Posts on Dejan Bosanac

Master your skills

Wed, 29 Jul 2026 00:00:00 +0000

We put a lot of effort into building context for our coding agents, but we rarely treat that context with the same engineering rigor as the rest of the project. I wanted to explore what it looks like when we do. Starting with the basics: what AGENTS.md and Agent Skills are and why they matter.

https://developers.redhat.com/articles/2026/07/27/standardize-project-context-agentsmd-and-agent-skills

Next up, I’ll dive into topics like authoring, testing, evals, CI integration, etc.

Messaging for IoT

Mon, 17 Aug 2015 00:00:00 +0000

Deploying message broker for an IoT use case introduces some new challenges to the broker scalability. We’re talking now about thousands of connections, consumers and destinations, which make us think of how we provision, configure and monitor our messaging infrastructure much more carefully. In this post I’ll try to sum up some of techniques that can be used with the current Apache ActiveMQ in terms to scale it better for IoT deployment. I’ll also describe some of the new features we developed for the 5.12.0 release to make it a better fit in this new world. And finally I’ll try to explain where we can go from here and what can we work on in the future.

ActiveMQ and HawtIO

Tue, 29 Apr 2014 00:00:00 +0000

We introduced HawtIO console as a tech preview in 5.9.0 ActiveMQ release, with an idea to replace the old and rusty web console in the distribution. Unfortunately, that idea didn’t go well with the rest of Apache community so it’s voted out and 5.9.1 is released without it. You can read more on the topic of distributing non-Apache developed web consoles in Apache projects in this (lengthy) thread if you’re interested.

Anyhow, there’s a lot of people out there who liked HawtIO and are asking questions on how to use it with the future (and some old) releases. So here, I’ll try to sum up different ways of how ActiveMQ and HawtIO can be used together.

MQTT over WebSocket transport in ActiveMQ

Fri, 05 Jul 2013 00:00:00 +0000

So, we have more and more users want to connect to ActiveMQ directly from the browser using WebSockets. For quite a while now we support Stomp clients which are really easy to use from JavaScript. Now, as more mobile users trying the same approach, we added support for very efficient binary MQTT protocol to the mix for upcoming 5.9.0 version.

The good thing is that you really don’t have to change anything on the broker side to support it. Both Stomp and MQTT can work over the same connector, as clients identify the protocol they want to use when they initialize the connection. We also provided a nice little demo using Eclipse Paho JavaScript client. You can play with the demo if you start the broker with activemq-demo.xml config like

Lightweight Messaging For Web And Mobile With Apache ActiveMQ

Tue, 14 May 2013 00:00:00 +0000

Messaging once was a thing of “enterprises” but times are changing fast and devs now want to use it from virtually any environment. I thought it’s important to talk about messaging technologies available for web and mobile, so I’ll give a talk about it at CamelOne and OSCON. If you’re attending one of those give me a ping, so we can have a chat over some beers.

Apache ActiveMQ 5.7.0 released

Mon, 08 Oct 2012 00:00:00 +0000

We managed to keep our goal of making more frequent releases and today we’re happy to announce Apache ActiveMQ 5.7.0. The main goal of this release was Java 7 compatibility. The project is built using JDK 6, but it’s tested to work properly with Java 7. This was needed as we now use Camel 2.10, which also added support for Java 7.

Besides this, there’s a couple of new features and close to two hundred bug fixes in this release. Some of the prominent new features are:

Pluggable ActiveMQ Storage Lockers

Thu, 13 Sep 2012 00:00:00 +0000

Shared storage master slave broker topologies depend on successful storage locking. Meaning that only a single broker (the master) is active and use the message database. So far locking was tied to a specific message store, so KahaDB was using shared file locking while JDBC store was using a specialized database table to keep slaves from starting. This work fine for the most use cases, but sometimes folks need to use a custom locker (like when the standard file locking doesn’t work on their NFS) or tune existing solutions.

Messaging Anti-Patterns: Part 3

Wed, 05 Sep 2012 00:00:00 +0000

OK, after basic anti-patterns discussed in part 1 and 2 of this series, it’s time to discuss a bit more sophisticated messaging anti-patterns and how to write better messaging-oriented applications.

Using appropriate message type
#

So let’s start with the first principles of messaging. Why we want to use a message broker in our architecture? The most probable answer is to exchange data in asynchronous and lously-coupled way between our systems. In that terms we should see how our data are best represented in terms of messages. JMS specification defines a few types of message types to be used which I’d classify in two groups. In the first group I’ll put TextMessages and ByteMessages which provides a kind of a plain-sheet in terms of what kind of data is carried in the message body. I think that you should strongly consider using only these message types as they provide a framework for loosely-coupled data exchange without introducing unnecessary complexity. Let’s cover briefly other message types and discuss what they bring to the picture:

Messaging Anti-Patterns: Part 2

Fri, 17 Aug 2012 00:00:00 +0000

OK, now that you promised that you won’t store your messages in the broker (see part one of this post series), let’s consider one more thing that you should avoid when dealing with messaging systems.

Short-lived connections
#

One thing that reoccur regularly is folks (knowingly or unknowingly) creating and tearing connections to the broker for every message they produce and consume.

Messaging Anti-Patterns: Part 1

Tue, 31 Jul 2012 00:00:00 +0000

If you have a hammer everything looks like a nail, right? So we all witnessed that people sometimes try to solve the problem with wrong technology. Heck we probably all did it at one point or another. Common reasons are familiarity with an exiting technology stack we have at hand or perception that some of the features will justify it all. But using any technology in a way it’s not designed for, will lead to all kind of problems and you’ll eventually be forced to do it properly (probably cursing at the project in question because it hasn’t met you wrong expectations).

Conference week wrap-up

Sat, 19 May 2012 00:00:00 +0000

I had a blast of a week at CamelOne and JEEConf. Both organized perfectly and awesome crowd all around.

CamelOne was packed with FuseSource customers and users with a great feedback on the things we do. There were a lot of interest in Fuse Fabric which should help folks provision their integration infrastructure with ease. I covered how Fabric can help with complex ActiveMQ deployments and you can find the slides embedded below.

ActiveMQ 5.6.0 and other news

Tue, 08 May 2012 00:00:00 +0000

We just released Apache ActiveMQ 5.6.0. It was a long-awaited maintenance release, but however there are a few very significant new features that was worth waiting for. Those include a new LevelDB store, MQTT and Stomp 1.1 protocols support and self-balancing cluster clients, to name a few. I already written about clustering here and there sure will be a lot of things to write about these other features as well in coming days.

ActiveMQ in the cloud

Tue, 10 Apr 2012 00:00:00 +0000

FuseSource just announced a public beta of new Enterprise products (Read more about it in Rob’s post). So it’s time to give you a bit more details on what we were working on for the past few months. One thing I want to emphasize in this post is how this project improves the experience of deploying and managing ActiveMQ brokers. Fuse Fabric (the central engine behind Fuse Enterprise) can help you provision and manage your brokers better and additionally help with cloud deployments.

New ActiveMQ failover and clustering goodies

Tue, 14 Feb 2012 00:00:00 +0000

For the last two weeks I’ve been working on some interesting use cases for the good ol’ failover transport. I finally have some time at my hands, so here’s a brief recap of what’s coming in 5.6 release in this area.

First there’s a new feature, called Priority Backup. It’s described in details here, but in a nutshell it provides you with the mechanism of prioritizing your failover urls and keep your clients connected to them as soon as they are available. The most obvious use case for this is to keep your clients connected to the broker in local data center whenever you can. By doing this, you can both have better performances and stability of your clients, but also save on your bandwidth bills.

ActiveMQ networks and advisory messages explained

Wed, 21 Dec 2011 00:00:00 +0000

Recently Jakub wrote an excellent blog post explaining more on how ActiveMQ networks work. The one thing that somehow always got unexplained and confused users over time is the connection between network of brokers and advisory messages. I finally took some time to document it and introduce some enhancements we have in this area for the upcoming 5.6 broker release. Read more here on how network connectors use advisory messages and how you can tune all that in complex and high load environments.

Advanced messaging with Apache ActiveMQ slides

Mon, 23 May 2011 00:00:00 +0000

Slides are available at slideshare now:

Advanced messaging with Apache ActiveMQ

View more presentations from dejanb

JEEConf Session

Wed, 11 May 2011 00:00:00 +0000

I’ll be speaking on “Advanced Messaging with ActiveMQ” at JEEConf in Kiev, Ukraine on Saturday May 21st.

Just arrived!

Mon, 28 Mar 2011 00:00:00 +0000

ActiveMQ in Action released

Mon, 21 Mar 2011 00:00:00 +0000

Book projects always (at least for me) takes quite longer to finish than you anticipate at the beginning. But unlike everything we do in software development, when it is finally finished, you get the real physical thing you can hold in your hands. And that’s always a great feeling.

I’m happy to announce that ActiveMQ in Action is released. You can already get final eBook, while the print version will hit the shelfs on March 24th.

ActiveMQ 5.5: Audit Logging

Thu, 20 Jan 2011 00:00:00 +0000

The PCI DSS (Payment Card Industry (PCI) Data Security Standard) v2.0, specifies that all user actions must be audited, so they can be inspected later if needed. To be deployable in such environments, we added audit logging to ActiveMQ. In this article you can find the basics on how to configure and use it. Here, I’d like to expand the topic a bit and talk about add-ons you can find in Fuse Message Broker.

Software scalability | Belgrade meetup 04

Fri, 14 Jan 2011 00:00:00 +0000

Update: Slides are available at http://www.slideshare.net/fusesource/introduction-to-apache-camel

I’ll be introducing Apache Camel at next Software Scalability | Belgrade – meetup on January 29th. The full announcement can be found here

How to monitor ActiveMQ networks

Wed, 05 Jan 2011 00:00:00 +0000

If you’re running ActiveMQ in a distributed setup using network of brokers, you’re probably interested in techniques available to monitor your network. This usually implies viewing the status of the network bridges and generating events when the status changes. There were some improvements in this area for the next 5.5 release and here I’ll try to explain this topic a bit more.

To demonstrate these techniques we need a simple network, so take a look at the one shown in the following diagram.

ActiveMQ in Action in Production

Thu, 28 Oct 2010 00:00:00 +0000

It’s always a good feeling when the book project goes into the production, and that’s what happened to ActiveMQ in Action this week.

If you already bought MEAP access plus printed version of the book, you can expect your printed version in the next few months. If not, it’s still not too late as we’re offering 40% discount to celebrate going into the production. Just use activemq40 coupon code at the time of checkout.

ActiveMQ 5.4.1: Encrypted passwords

Fri, 03 Sep 2010 00:00:00 +0000

While configuring ActiveMQ for a production use, you usually need to store passwords in your configuration files. Passwords are usually needed for:

Simple authentication plugin
JDBC/LDAP passwords
Accessing secured brokers by Web Console, Camel, etc

Naturally, people don’t want to keep plain passwords in the configuration files. ActiveMQ 5.4.1 comes with a solution for that. Thanks to the integration with Jasypt library, your passwords can be now stored encrypted.

For a full description of this new feature see http://activemq.apache.org/encrypted-passwords.html.

What's new in Apache ActiveMQ 5.4.0

Tue, 17 Aug 2010 00:00:00 +0000

Apache ActiveMQ 5.4.0 is out. Beside our usual dedication to making it bullet-proof by adding a lot of test cases and resolving issues reported by our vibrant community, this release contains a lot of new features (some of which has already been covered here). In this post I’ll try to sum up the new features that we included in this release. As the development pace was very rapid, some of them haven’t been documented yet, but that’ll change soon too. So let’s start:

Fast producer failover with ActiveMQ

Mon, 16 Aug 2010 00:00:00 +0000

When you’re sending messages to a cluster of ActiveMQ brokers using failover protocol and the current broker dies, the transport will try to connect and send messages to the next one. If that one is unavailable it will try next and so on and so on. So what happens when all brokers in the cluster are down? You’ll get the feeling that send call is hanging. At least until one of the brokers gets up again.

ActiveMQ 5.4: Seamless OSGi Integration

Mon, 02 Aug 2010 00:00:00 +0000

For upcoming ActiveMQ 5.4.0 release we did a lot of work to make it a better citizen in OSGi land. Let’s walk through some of the stuff you can do now. First of all download and install recently released Apache Karaf 2.0.0.

Now if you want to play with all these stuff before the ActiveMQ 5.4.0 is officially released, you need to edit

${KARAF_HOME}/etc/org.ops4j.pax.url.mvn.cfg

and add

https://repository.apache.org/content/repositories/snapshots/

to the list of available repositories.

Software scalability | Belgrade meetup

Thu, 01 Jul 2010 00:00:00 +0000

I’ll be speaking on “Enterprise ActiveMQ” at “Software Scalability | Belgrade” first meetup on Saturday, July 03 2010. The full announcement could be found here

Securing ActiveMQ 5.3.1 console

Fri, 21 May 2010 00:00:00 +0000

In many environments, users want to restrict access to ActiveMQ web server (Jetty) and web console application in particular. Here’s how to do it for ActiveMQ 5.3.1 version of broker.

In 5.3.1, the whole web server configuration is placed in the ${ACTIVEMQ_HOME}/conf/jetty.xml file. The configuration file you can find at here is a drop-in replacement for a default jetty configuration and you should place it in your configuration folder.

Besides that you’ll need to create a ${ACTIVEMQ_HOME}/conf/jetty-realm.properties with the following content:

ActiveMQ 5.3.1 Released

Tue, 23 Mar 2010 00:00:00 +0000

Apache ActiveMQ 5.3.1 has just been released. It’s primarily the maintenance release, including nearly 100 bug fixes and improvements over the previous 5.3.0 version. The full list of improvements and bug fixes, as well as the download link, can be found at the release page.

JDBC message store - a big effort has been made to make JDBC store as reliable as other file-based stores for use in complex high-load use cases.
nio and stomp+nio transports - initial implementation of stomp+nio transport, introduced in 5.3.0 version contained some resource leaks, but also revealed some problems with the nio transport. All these are now fixed, thoroughly tested and ready for production use
OSGi integration - a lot of small improvements in this area should provide much better integration of the broker in OSGi environments. Especially, we provided resources for seamless deployment in Apache Karaf OSGi runtime. This will be the topic of the following blog post (so stay tuned!)
Web console security - Web console is now secured against XSS and XSRF attacks, so it’s safe to be deployed publicly (of course with proper authentication set in place)

Enjoy this release, while we work on delivering 5.4.0 in coming months (or even weeks) with more bug fixes and features, such as scheduled messages and web socket support

ActiveMQ 5.4: Stomp over Web Sockets

Mon, 22 Feb 2010 00:00:00 +0000

Exchanging messages with the broker directly from the web browser was always interesting use case (and used by many developers). That’s why ActiveMQ was supporting Ajax API for the long time. It uses Jetty Continuations to implement threadless waiting and asynchronous delivery of messages to the web page.

HTML 5 introduced web sockets, as a standardized way to communicate asynchronously with the server from a web page. This is practically an ideal channel for implementing asynchronous messaging for web pages, so it’s no surprise we had it on a todo list for a long time. Also, since JavaScript easily handles text and JSON formatted data, Stomp protocol is a natural choice for the wire protocol to be used over web sockets.

ActiveMQ producer flow control with timeout

Fri, 29 Jan 2010 00:00:00 +0000

ActiveMQ producer flow control feature allows you to prevent overflowing the broker by slowing down fast producers. Thus far you had two options, the producer send() method will either wait until space becomes available, or fail if it’s configured through sendFailIfNoSpace property, like this:

<systemUsage>
 <systemUsage sendFailIfNoSpace="true">
   <memoryUsage>
     <memoryUsage limit="20 mb"/>
   </memoryUsage>
 </systemUsage>
</systemUsage>

For 5.3.1 version of the broker we added a third option. You can now configure the broker to do the producer flow control with timeout. If you configure <systemUsage> like this (using sendFailIfNoSpaceAfterTimeout property),

Jettison 1.2 Released

Mon, 18 Jan 2010 00:00:00 +0000

Jettison version 1.2 has been released. The highlights of this release are:

Refactored MappedXMLStreamWriter - which solved many issues with serializing arrays
Plugable type converters and support for 64-bit long conversion

You can find the full change log for this release on the Download page. Enjoy

Handling IOException in ActiveMQ

Fri, 20 Nov 2009 00:00:00 +0000

When you encounter IOException trying to persist a message on the disk, you know something has gone wrong. One of two things usually happen:

Either your disk is dead, or disconnected in case you use network disks
Or you just don’t have more space on the disk

Depending on the type of the exception you may encounter, you might want to take a different action. For upcoming 5.3.1 release we implemented fully configurable IOException handling which can be tuned to your need.

Fuse Stomp project

Thu, 29 Oct 2009 00:00:00 +0000

In our attempt to provide better future for Stomp protocol, we already moved specification under ActiveMQ project umbrella, where all future specification improvements will be done. Another necessary step is to provide high-quality Stomp clients for use in different development environments. For that purpose, we created Stomp project on FUSE Forge. It should provide a project hosting environment for various Stomp clients.

For starters I released PHP Stomp Client 1.0.0. It’s a natural extension of all the work previously hosted on Codehaus + Google Code. It is now stabilized, with a lot of bug fixes and released as 1.0.0. All future development will be continued on the FUSE Forge as it provides much better hosting environment than we used thus far.

Python messaging: ActiveMQ and RabbitMQ

Tue, 20 Oct 2009 00:00:00 +0000

I found myself recently with a task of testing various Python messaging clients. In this article I’ll present my findings regarding performance and scalability on two Python clients connecting to ActiveMQ and RabbitMQ message brokers.

For ActiveMQ Python client, I used pyactivemq library version 0.1.0. It’s basically a Python wrapper for ActiveMQ-CPP library, allowing Python clients to communicate with the broker using both OpenWire (ActiveMQ specific binary protocol) and Stomp (Simple text-oriented protocol) protocols. Since it uses ActiveMQ-CPP, installation requires special attention and some of those details you can find in a related blog post.

Apache ActiveMQ 5.3.0 Released

Tue, 13 Oct 2009 00:00:00 +0000

After more than a year in development, we finally released 5.3.0 version of ActiveMQ. It contains over 300 bug fixes, but also some of the neat new features. The full list of features and bug fixes, as well as the download link can be found at the release page

Here, I would like to emphasize just some of the new features:

New KahaDB persisten store, which improves recovery times and scalability in a great deal
A default configuration now focused more on production then demoing all features. You can also find some useful configuration examples for different scenarios, like vertical scaling or throughput
Camel 2.0.0 integrated along with it’s web console for managing endpoints and routes
… and much, much more

You can expect more useful resources on ActiveMQ 5.3.0 in coming days.

XML to JSON

Mon, 21 Sep 2009 00:00:00 +0000

While working on Jettison, I often have need to convert XML to JSON. Here’s a simple method that uses XStream and Jettison to do this conversion.

import java.io.StringReader;
import java.io.StringWriter;

import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.io.copy.HierarchicalStreamCopier;
import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
import com.thoughtworks.xstream.io.xml.XppReader;

public class Test {

	public static void main(String[] args) throws Exception {

		String xml = "ToveJaniReminder" +
				"Don't forget me this weekend!";

        HierarchicalStreamReader sourceReader = new XppReader(new StringReader(xml));

        StringWriter buffer = new StringWriter();
        JettisonMappedXmlDriver jettisonDriver = new JettisonMappedXmlDriver();
        jettisonDriver.createWriter(buffer);
        HierarchicalStreamWriter destinationWriter = jettisonDriver.createWriter(buffer);

        HierarchicalStreamCopier copier = new HierarchicalStreamCopier();
        copier.copy(sourceReader, destinationWriter);

        System.out.println(buffer.toString());
	}

}

All conversion problems, like lists representation are handled by Jetttison. This example uses Mapped convention, but of course, BadgerFish notation can be used as well.

Wire format negotiation timeout and log4j jms appender FAQs

Tue, 11 Aug 2009 00:00:00 +0000

Some folks have been experiencing problems with wire format negotiation timeouts. Sometimes it was due to overloaded brokers or lousy networks, but misconfiguration of log4j jms appender could also be one of the causes. So, I wrote two FAQ entries that covers this topic:

Using log4j appender with ActiveMQ

Wire format negotiation timeout exception

Enjoy

Stomp Future

Tue, 21 Jul 2009 00:00:00 +0000

While thinking about the future of Stomp protocol, we concluded that the best place for future maintenance of the specification is under umbrella of ActiveMQ project. There are a couple reasons for this, but it basically boils down to two facts:

Apache infrastructure is much better suited for this task than the one currently used at Codehaus
Most of the Stomp contributors are also ActiveMQ committers, so this transition feels natural in this respect.

As a starting point, we created an ActiveMQ sub-project http://activemq.apache.org/stomp/ which will be the home of the all future work on the protocol. At the moment, we only ported information related to Stomp version 1.0 (specification and related articles) to this new project. Soon, we’ll start working on protocol specification version 1.1, using the current idea pool as a base.

pyactivemq on Ubuntu

Tue, 07 Jul 2009 00:00:00 +0000

pyactivemq is a Python library that enables Python clients to communicate with ActiveMQ using both OpenWire and Stomp protocols. To do that it wraps ActiveMQ-CPP library, so it involves some compiling to make it all work. While building instructions for both ActiveMQ-CPP and pyactivemq and clear and concise, I found some additional steps were need to make it all work on Ubuntu box. I’ll post it here for my future reference and hopefully it can be useful to other folks.

ActiveMQ in Action MEAP update

Fri, 12 Jun 2009 00:00:00 +0000

There are new chapters available on ActiveMQ in Action book in Manning Early Access Program (MEAP). This time you can read:

Chapter 12 - Tuning ActiveMQ for performance - gives detailed explanation on various techniques you can use to improve your brokers’ performances
Chapter 14 - Administering and managing ActiveMQ - explains how to monitor your broker using JMX, advisory messages and such

Enjoy reading!

Fuse Message Broker 5.0.0.28 released

Fri, 12 Jun 2009 00:00:00 +0000

Another month, another Fuse message broker 5.0 branch update. This time, it comes with HTTP transport and a message consumer improvements.

ActiveMQ OSGi integration

Wed, 10 Jun 2009 00:00:00 +0000

OSGi containers are becoming a deployment platform of choice for many developers these days. That’s why nearly all server-side Java software is packaged as OSGi bundles and ActiveMQ is not an exception. I wrote an article that goes into the details on how to deploy and use ActiveMQ broker and web console in Apache Karaf (and ServiceMix) OSGi environments. I hope you’ll enjoy reading it.

Fuse Message Broker 5.3.0.2 released

Mon, 01 Jun 2009 00:00:00 +0000

We’ve cut and thoroughly tested another Fuse Message Broker 5.3 release. If you need a stable 5.3 ActiveMQ version, try it out. You can find more info about this release here.

Fuse Message Broker 5.0.0.27 released

Tue, 19 May 2009 00:00:00 +0000

Another incremental improvement of the ActiveMQ 5.0 branch. Check release notes for more details.

Fuse Message Broker 5.3.0.1 released

Thu, 23 Apr 2009 00:00:00 +0000

While waiting for Apache ActiveMQ 5.3, you can try our latest cut of Fuse Message Broker 5.3.0.1. A lot of issues are already merged and thoroughly tested. Also, it very easy to do a switch back and forth (take a look at this article for more details).

Jettison 1.1 released

Thu, 23 Apr 2009 00:00:00 +0000

Jettison 1.1 has been released. New features in this release are:

DOM API
Type converters
OSGi bundle packaging

You can find the full change log for this release on the Download page. Enjoy!

ActiveMQ continuos intergration

Fri, 17 Apr 2009 00:00:00 +0000

ActiveMQ has been added to Hudson continuous-integration server instance at Apache http://hudson.zones.apache.org/hudson/job/ActiveMQ/. Now you can have more insight into test runs and snapshot builds. Hudson will also send failure reports to our dev mailing list, making us address them promptly. As a part of this change, the snapshots location and Maven repository has changed. If you’re using ActiveMQ snapshots in your projects, be sure to add the following repository to your Maven configuration:

Asynchronous messaging for web sites

Tue, 07 Apr 2009 00:00:00 +0000

Nice explanation of importance of asynchronous messaging by Dooplr CTO Matt Biddulph at dConstruct 2008

And I am not going to any update, but I just want to say to every developer in the room that you need to be playing with asynchronous messaging right now on your servers. You need to grab Apache ActiveMQ or Beanstalk, or play with Amazon’s Simple Queue system. And start building a different sort of gearing into your website.

ActiveMQ in Action discount

Wed, 11 Mar 2009 00:00:00 +0000

If you were planning to buy ActiveMQ in Action (ebook, print or both), you’re in luck. Until March 23rd, you can use coupon code activemq40 at Manning site and get 40% off the regular price.

Fuse Message Broker 5.0.0.26 released

Wed, 25 Feb 2009 00:00:00 +0000

Fuse Message Broker 5.0.0.26 is just released. It’s mostly a work towards better stability, but there is also a couple of important bug fixes (release notes). If you’re still on ActiveMQ 5.0 branch, be sure to give it a try.

Unacking messages with Stomp

Tue, 17 Feb 2009 00:00:00 +0000

Quite often people ask how to “unacknowledge” the message using Stomp. I wrote a brief FAQ entry (with an example):

http://activemq.apache.org/how-do-i-unack-the-message-with-stomp.html

Also, be sure to use 5.3-SNAPSHOT (or later), since there were some improvements in that area recently.

Fuse Message Broker 5.2.0.2 released

Mon, 09 Feb 2009 00:00:00 +0000

Fuse Message Broker 5.2.0.2 has just been released, with a couple of issues fixed. You can find release notes here.

I would like to take this chance to explain Fuse releases a bit and how you can easily switch between Apache and Fuse releases of ActiveMQ. Apache ActiveMQ and Fuse Message Broker are practically the same software (created from the same code base), but while you can expect Apache ActiveMQ releases every six months or so we try to have a monthly release cycle at Fuse. So, if you wait for version 5.3 to be released and you don’t want to use snapshot releases, you can use Fuse Message Broker releases 5.2.0.x which every month include a couple of new fixes. Fuse releases are thoroughly tested, so you can safely use it in your production environment.

New chapters of ActiveMQ in Action are available online

Thu, 05 Feb 2009 00:00:00 +0000

If you’re looking for ActiveMQ documentation, you can try reading online chapters of “ActiveMQ in Action” using Manning Early Access Program (MEAP) - http://www.manning.com/snyder/

New chapters has just been added:

Chapter 2 provides a detailed overview of ActiceMQ
Chapter 4 explains ActiveMQs message persistence options
Chapter 7 addresses the aspects related to providing messaging services to different platforms
Chapter 12 explains performance tuning techniques

I hope you’ll enjoy reading them.

Message groups just got a bit better

Mon, 26 Jan 2009 00:00:00 +0000

As the first sentence of the message groups documentation page says: message groups rock. One of the problem with them, however, was an inappropriate behavior in case you’re adding your consumers for the messages already stored in the broker (with appropriate message group parameters set). This also causes that message groups are not honored in master slave environment, because when master goes down you can end up with your producer sending some messages to the slave before your consumers subscribe.

Sending over failover transport with timeout

Mon, 12 Jan 2009 00:00:00 +0000

The failover transport proved to be useful for many use cases, but had one drawback. When no browsers are available, your send operation will hang. One of the ways to deal with this is to use TransportListener to detect and handle those cases.

From 5.3 version onwards, you will be able to use new timeout option on the protocol that should solve this problem naturally. So, if you use an URL like this:

Apache ActiveMQ 5.2

Fri, 21 Nov 2008 00:00:00 +0000

Apache ActiveMQ 5.2 is finally released. It is mainly a maintenance release, but there are also a couple of new features, like extended Advisory support and such. If you use ActiveMQ, be sure to give this release a try.

Stomp v1.1 thoughts

Tue, 23 Sep 2008 00:00:00 +0000

Update: There is now a wiki page on Stomp site for this, please go there if you are interested in Stomp v1.1

As discussed in this thread some time ago, there is a need to start working on Stomp version 1.1 protocol specification (and implementation), if nothing else then to support types for message properties. I would like to discuss some of the ideas regarding this, before I start working on it. So any thoughts and comment are more than welcomed.

Jettison in practice

Wed, 17 Sep 2008 00:00:00 +0000

Joel Confino of Chariot Solutions, LLC wrote an article on building Web 2.0 Web applications using jQuery, Spring MVC, and XStream/Jettison. It’s good to see Jettison in practice :)

links for 2008-08-11 [delicious.com]

Mon, 11 Aug 2008 00:00:00 +0000

Home - Adhearsion.com

rails-like framework for developing with asterisk

(tags: voip ruby framework)

ActiveMQ in Action

Fri, 08 Aug 2008 00:00:00 +0000

As Bruce and Rob already said, our current work on “ActiveMQ in Action” book is available in Manning Early Access Program (MEAP).

We will try to cover all aspects of ActiveMQ, from basic stuff such as JMS basics and how to run ActiveMQ for the first time to complex broker topologies and performance tunning.

I hope you’ll enjoy reading it.

links for 2008-07-21

Mon, 21 Jul 2008 00:00:00 +0000

Handling Joins in Ibatis

Missing from the manual

(tags: ibatis java)

Jettison 1.0.1 released

Mon, 09 Jun 2008 00:00:00 +0000

We’re proud to present Jettison 1.0.1 release. This is just a bugfix release, while new features (such as new APIs (DOM and SAX) and type converters) are planed for 1.1 release (which is expected soon). Download 1.0.1 from the Download section and refer to the User’s Guide for more information.

links for 2008-04-10

Thu, 10 Apr 2008 00:00:00 +0000

Virtualbox VM + Ubuntu

Have to try this out

(tags: vm ubuntu)

links for 2008-04-04

Fri, 04 Apr 2008 00:00:00 +0000

Java Community News - Sun Releases Beta of Deployment-Focused Java SE 6 Update

JRE 6 update with Java kernel and better support for desktop integration

(tags: java update kernel)

Indexing repositories

Mon, 31 Mar 2008 00:00:00 +0000

Dependency management was always one of the crucial Java project management tasks. It’s where tools such as Maven and Ivy make all the difference and allow developers to maintain their project dependencies in an easy way. There are two important elements for this to happen:

Centralized repositories - containing library JARs
Metadata - describing those JARs and creating repository structure

This is something we have for years thanks to the Maven developers. But if you ever tried to manage dependencies manually in your project, you know how tedious this task can be:

links for 2008-03-18

Tue, 18 Mar 2008 00:00:00 +0000

John Resig - Cross-Site XMLHttpRequest

one small step for Firefox, one giant leap for browsers

(tags: cross-domain ajax firefox)

links for 2008-02-25

Mon, 25 Feb 2008 00:00:00 +0000

O p t i m i z i n g

thoughts that just make sense

(tags: Java optimization)
Project SAM - Simple Asynchronous Messaging -

Looks a lot like PHP Stomp client

(tags: php messaging)

Customizing Enums

Mon, 11 Feb 2008 00:00:00 +0000

Enumerated types (enums) are a way to define fixed set of constants, so helpful in many areas of software development. In the most common case, in your Java code written for Java 5 or newer, you will use enums for int constants and replace chunks of code that look like this

    public static final int DIRECTION_NORTH     = 0;
    public static final int DIRECTION_SOUTH     = 1;
    public static final int DIRECTION_EAST      = 2;
    public static final int DIRECTION_WEST      = 3;

with something like this

links for 2008-02-08

Fri, 08 Feb 2008 00:00:00 +0000

The year 2038 bug

will it ever end?

(tags: 2038 bug programming)

Jettison 1.0 RC3 Snapshot

Wed, 06 Feb 2008 00:00:00 +0000

For those who can’t wait for 1.0 RC3 to be released (with fixed behavior for converting nested lists and maps from XStream), you can download patched snapshot from here

links for 2008-01-17

Thu, 17 Jan 2008 00:00:00 +0000

Jonathan Schwartz’s Blog: Helping Dolphins Fly

sun buys mysql form $1billio

(tags: sun mysql)
Java SE 6 Update 4 Release Notes.

a lot of bug fixes

(tags: java)

links for 2008-01-09

Wed, 09 Jan 2008 00:00:00 +0000

How To Install Internet Explorer On Ubuntu (Feisty Fawn, Edgy Eft And Dapper Drake) | HowtoForge - Linux Howtos and Tutorials

installed 2.0.5 on gutsy … works like a charm

(tags: ubuntu linux ie)

links for 2008-01-04

Fri, 04 Jan 2008 00:00:00 +0000

Sam Ruby: WORA

django on jython

(tags: django jython jvm)

Dealing with large code bases

Wed, 02 Jan 2008 00:00:00 +0000

If you haven’t already, be sure to read Steve Yegge’s post on his experience of dealing with large code bases (it’s a bit long post but an excellent read).

He explains the maintenance nightmare of his 500.000 lines of code game written in Java and quite correctly concludes that code size is a crucial problem for big software projects.

My minority opinion is that a mountain of code is the worst thing that can befall a person, a team, a company. I believe that code weight wrecks projects and companies, that it forces rewrites after a certain size, and that smart teams will do everything in their power to keep their code base from becoming a mountain. Tools or no tools. That’s what I believe.

Securing Stomp

Tue, 25 Dec 2007 00:00:00 +0000

If you ever wanted to use Stomp messaging protocol with secured ActiveMQ broker, you can now do it by downloading a 5.1 snapshot distribution. For more Stomp messaging security over unsecured networks you can additionally use Stomp over SSL, which makes Stomp + ActiveMQ perfectly secure messaging environment over unsecured networks. If PHP is your environment of choice, the PHP Stomp client implements these security mechanisms completely (including SSL connectivity).

Happy Holidays.

links for 2007-12-17

Mon, 17 Dec 2007 00:00:00 +0000

Andreas Sterbenz’s Blog : Weblog

useful utility class/application for adding server ssl certificates to keystores

(tags: java ssl jsse)

links for 2007-12-07

Fri, 07 Dec 2007 00:00:00 +0000

GNOME Do

quick-launcher for gnome

(tags: gnome launcher ubuntu)
xo-laptop: On the Open-Sourcing of Business « The Wayward Word Press

business side of open source

(tags: opensource business)

Extension methods proposals

Wed, 05 Dec 2007 00:00:00 +0000

There’s a quite interesting discussion in the blogosphere about proposed extension methods feature for Java 7. The problem tackled by this proposal is how to extend an API (interface) with new methods without breaking existing implementations. The example used in a discussion is a List interface and the sort() method. In order to add another method to the existing interface, Java developers today create static utility functions. Take for example the java.util.Collections class, which is a set of static helper methods for working with collections. Among them is of course the aforementioned sort method. Here’s a simple example:

links for 2007-11-29

Thu, 29 Nov 2007 00:00:00 +0000

Programming less (Scripting News)

The design of the central data structure of an app determines the quality of the app, in every way.

(tags: complexity development software)
Open Flash Chart -

Beautiful flash chart library

(tags: flash graph opensource charts)

Multiple Apache instances on Gentoo box

Tue, 27 Nov 2007 00:00:00 +0000

I’ve started looking how to enable both PHP4 and PHP5 on our (relatively) new dev box running Gentoo. The box is already running PHP4 so the task was to add PHP5 support as well.

The official guide is rich in options you can use to achieve this. I didn’t want any CGI since we use PHP vhost configurations extensively and I didn’t want to deal with suPHP as well. Since it is a dev box, it is totally OK to have two instances with similar configurations running on two different ports. Unfortunately, it is the part of the official docs that is not as complete as other parts and not working as advertised. So, here’s a mental note (for me) and perhaps a few hour saver for others.

Groovy StAX builder

Mon, 26 Nov 2007 00:00:00 +0000

I’ve always loved Groovy builders concept for handling (mostly creating) hierarchical documents. On the other hand I find StAX, pull-based processing API, to be one of my favorite methods for dealing with simple XML processing. It’s simple and fast, so what more can I ask for? Additionally, thanks to the Jettison project you can also use the StAX API to handle JSON documents. So, basically we can use one simple (standard) API to handle both XML and JSON documents in the same manner. The next logical step is to merge these two great pieces of technology into one.

links for 2007-11-26

Mon, 26 Nov 2007 00:00:00 +0000

Ctrl-Shift-B: Interactive Application Architecture Patterns

article discussing/comparing MVC and a few similar design patterns

(tags: Patterns programming architecture)

links for 2007-11-20

Tue, 20 Nov 2007 00:00:00 +0000

Zdot » Blog Archive » Building a Megajar with Maven2 - The Right Way

Use assembly plugin to create uberjar

(tags: maven2 uberjar assembly)

XStream and Spring OXM (Object/XML Mapping framework)

Fri, 16 Nov 2007 00:00:00 +0000

It all started when I tried to find a solution for customizing an XStream instance for my ActiveMQ XStream message transformer that would be better than currently used (extending a base transformer and providing a custom factory method that will do things like alias, converter, annotation, etc. settings). I wanted an easy solution to configure XStream instance in a Spring xml configuration file used in my application and provide that instance to all beans that need it (message transformer among others).

IJTC Wrap up

Mon, 12 Nov 2007 00:00:00 +0000

I had some really great time in Dublin at IJTC last week. Good people, good sessions and a lot of fun; what else could one expect?

There were a few sessions that covered projects that I’ve had on my radar for some time but never found time to look closer, such as Apache Camel and Spring Batch. Also, it’s always good to hear about good ol’ stuff (and what’s new about them), so sessions about Spring 2.5, ActiveMQ, Groovy & Grails were well appreciated.

Future of Java

Tue, 06 Nov 2007 00:00:00 +0000

Tomorrow, on Wednesday 7th, there will be a panel at IJTC with Joel Spolsky and James Strachan discussing the future of Java. It sounds very compiling to me and I hope to meet you there.

CVS, CentOS and SELinux

Fri, 02 Nov 2007 00:00:00 +0000

I was migrating a CVS repository from one server to another today and ran on the interesting issue. I was getting a “Permission denied” error on the CVSROOT/config file no matter what privileges were set. It turns out that problem is with SELinux on CentOS, so the easiest solution is to just turn it off.

/usr/sbin/setenforce 0

If you want to be sure that it will be turned off after the server restart, just edit the /etc/sysconfig/selinux file and set SELINUX to permissive

links for 2007-11-01

Thu, 01 Nov 2007 00:00:00 +0000

Move or migrate user accounts from old Linux server to a new Linux server

nice checklist for migrating linux servers - just copy/paste commands and you’re done

(tags: linux migration sysadmin server)

links for 2007-10-26

Fri, 26 Oct 2007 00:00:00 +0000

Mozilla Labs Blog » Blog Archive » Prism

thank you!

(tags: mozilla web applications)

IJTC Session

Wed, 24 Oct 2007 00:00:00 +0000

I will be speaking on Scripting with balance at Irish Java Technology Conference in Dublin (IJTC) on November 9th, 2007. The full announcement could be found here

links for 2007-10-18

Thu, 18 Oct 2007 00:00:00 +0000

Migrating data centers with zero downtime on Dion Almaer’s Blog

often forgotten knowledge of web application migration

(tags: web application migration)
InfoQ: Read/Write Splitting with MySQL-Proxy

very nice stuff

(tags: database mysql)

Multi-Language VM

Wed, 17 Oct 2007 00:00:00 +0000

OpenJDK community has a new project, Multi-Language VM (or just mlvm). It is announced by John Rose, from Sun, on the announcement list. The focus of the project will be to prototype JVM features beneficial for dynamic languages and remove “pain points” that current dynamic language developers have with standard JVM.

Here’s the snippet from the announcement:

This project will be open for prototyping JVM features aimed at efficiently supporting languages other than Java.

links for 2007-10-06

Sat, 06 Oct 2007 00:00:00 +0000

Software Is Hard

the title says it all

(tags: software development complexity)

links for 2007-09-26

Wed, 26 Sep 2007 00:00:00 +0000

Monitor and diagnose performance in Java SE 6

Java SE 6 Monitoring and management enhancements

(tags: Java jmx)
Welcome to ntop.org

network monitoring tool

(tags: network monitoring)

Scripting with Balance in Design and Performance

Fri, 21 Sep 2007 00:00:00 +0000

java.net has published an article titled Scripting with Balance in Design and Performance

JUG-NS session

Tue, 18 Sep 2007 00:00:00 +0000

I will be speaking on Scripting in Java in Novi Sad on September 19th, 2007. The full announcement could be found here (in Serbian)

links for 2007-09-12

Wed, 12 Sep 2007 00:00:00 +0000

Jayasoft Community Site - Ivy

Dependency manager for Ant

(tags: Java Ant opensource)
LiquiBase: Database Refactoring

Nice database refactoring tool

(tags: database refactoring java opensource)

Scripting API for everyone

Wed, 12 Sep 2007 00:00:00 +0000

I definitely think that dynamic languages for Java platform is an important topic. In that context, a Scripting API as a standardized scripting framework has its own role for Java developers. It is definitely a good thing it is included in JDK 6, but the lack of proper support for earlier JDK’s, in my opinion, slows down its wider adoption.

Why is this important? On one side, there are developers that work on “in-house” applications and solutions. Although it may seem that JDK (or JRE) upgrade process in such environments is not a big deal, it is usually a process that is pretty inertial. Many arguments are used in discussions, from compatibility issues and testing needs to “don’t fix it if it ain’t broken”, but also the inertia factor could be often associated to plain laziness.

Daily Snapshots

Fri, 27 Jul 2007 00:00:00 +0000

From today on, continuous integration process is set up for JQR and daily snapshots are available in the repository.

Asynchronous job execution

Wed, 18 Jul 2007 00:00:00 +0000

In software development we are often encouraged to decouple things in order to achieve greater flexibility in our code. So we decouple model objects from views, interfaces from their implementation, etc.

Here, I would like to write about different kind of decoupling, front-end from back-end. In many cases, projects tend to depend on resources that are either unreliable or overloaded. For example, besides your “main” database, you may need to write data to some LDAP server that is overloaded or you need to provide some data to the resources over the unreliable network connection. In most of these use cases, these operations are triggered by users through the user interface (web or stand-alone application). It is totally unnecessary (and usually unacceptable) to have your users wait a few minutes for operation to complete or in worse case to have dysfunctional system just because one resource is unavailable.

JQR 1.2.0 released

Fri, 29 Jun 2007 00:00:00 +0000

Sensatic JQR 1.2.0 has been released.

Eclipse Europa

Fri, 15 Jun 2007 00:00:00 +0000

On 29 June, Eclipse community will be richer for the new Europa release. It is a coordinate release of 21 Eclipse Foundation projects. The main component of this release is certainly new 3.3 version of the Eclipse Platform. Others include prominent projects from domains of administration, modeling, development and tools, such as Eclipse Communications Framework (ECF), Eclipse Modeling Framework Project (EMF), Dynamic Languages Tool Kit (DLTK) and Business Intelligence Reporting Tools (BIRT). This is definitely an important Eclipse release and a good news for all Eclipse users.

Integrating ActiveMQ Web Console

Thu, 07 Jun 2007 00:00:00 +0000

If you build an application that integrates ActiveMQ broker, it makes sense that you want to integrate its web console as well. It provides your users with basic monitoring and management operations. One road you can take is to integrate it as a WAR archive, but as you already have a whole lot of ActiveMQ integrated, you probably want to include just necessary subset of libraries and files and always have most up to date version of it.

JQR 1.1.0 released

Sat, 02 Jun 2007 00:00:00 +0000

Sensatic JQR 1.1.0 has been released.

(Not yet)Commons SSL

Wed, 30 May 2007 00:00:00 +0000

If you ever tried to work with SSL Socket connections in Java, you probably know that Java, by default, supports its own JKS and PKCS12 certificate formats. For those who need to work with OpenSSL it is usually suggested to convert keys and certificates to PKCS12 and then import them in the keystore using the keytool command provided with the JDK.

While all this is not a big deal for most of the applications, there should be a better solution for projects that rely heavily on SSL. Not-yet-commons-ssl project, called liked this because it is still in the Apache incubation process, aims to simplify Java and SSL integration.

XStream 1.2.2

Fri, 25 May 2007 00:00:00 +0000

XStream 1.2.2 is released with JettisonMappedXmlDriver used for serialization and deserialization from JSON. It is the driver first presented in Java and JSON post. All modifications are submitted to Jettison and XStream projects respectfully and documented in an appropriate tutorial (http://xstream.codehaus.org/json-tutorial.html). From now on, XStream has a full support for JSON serialization. Enjoy.

Changing CVS Root from shell

Thu, 24 May 2007 00:00:00 +0000

Here’s a simple script that recursively changes CVS/Root files in the project tree

find . -name Root -exec sh -c 'echo :pserver:example@cvs.example.com:2401/var/cvsroot 
> {}' \;

Note sh -c segment of -exec switch, which is necessary in order to successfully redirect to appropriate files.

This could be useful for updating deployed projects with the repository that has moved (for any reason).

Scripting and asynchronous messaging

Fri, 04 May 2007 00:00:00 +0000

One of the lessons we can learn from early success of the Web was making of ideal environment for use of scripts. There were two main components of the Web platform:

Web server (Apache), as an infrastructural component that had to be fast and reliable
Web application as a collection of scripts (Perl, PHP, Python), providing the content in an easy manner

The Web as we know it today is a much different place; applications talk to each other through variety of web service protocols, we have Ajax and all these new cool toys. But one principle remains the same: we need reliable infrastructure software with easy integration of scripts for fast creation of content and logic.

Can Servlet containers scale?

Wed, 04 Apr 2007 00:00:00 +0000

Filip Hanik of Covalent Technologies wrote an excellent article in which he describes his series of performance/scalability tests of the new NIO connector that has been added to Tomcat 6. In tests he also includes Jetty and Glassfish containers. The article contains very good explanation of challenges in adapting NIO environment to blocking IO requirements. The good news is that the answer to the question from the title is yes, servlet containers can scale, led by Tomcat 6 that handled 16000 concurrent connections without problems.

Velocity 1.5

Wed, 21 Mar 2007 00:00:00 +0000

As you all have probably heard, Velocity 1.5 was released last week. It is the first release of this project in last three years. This is certainly a long release cycle and it is not unusual that some people considered it a “dead project”.

I have some projects that use Velocity as a template engine of choice and over the time I’ve collected a “wish list” of features that I missed. Due to lack of new releases, I’ve considered switching to other template engines, such as FreeMarker and WebMacro, but actually never found time to do that.

New Date/Time and Rest APIs for Java

Thu, 22 Feb 2007 00:00:00 +0000

There has been some very interesting activity in JCP land lately, namely acceptance of new Date and Time API (JSR 310) and proposal of the JavaTM API for RESTful Web Services (JSR 311).

Usual first reactions to the JSR 310 that I saw on the web were “finally” or “too late”, but I think that “better late then never” should be applied in this case. People behind this specification are developers of Joda time and this API will be heavily based on Joda time, which has been an excellent replacement for traditional Java date/calendar API (and must-have tool in your toolbox) for years. Beside the initial goal, to provide lightweight and simple API, one of the area of interest will be interoperability with JDBC. The general attitude toward this spec is maybe best described by the Google’s voting comment: On 2007-01-30 Google Inc. voted Yes with the following comment: We are thrilled to see this happen! Hopefully, this specification will be included in Java 7.

Tuning Derby

Wed, 31 Jan 2007 00:00:00 +0000

OnJava has published an article titled Tuning Derby

Singletons and lazy loading

Fri, 26 Jan 2007 00:00:00 +0000

Probably the first design pattern that every software developer learns is Singleton and lazy loading of Singleton classes.

The usual example, goes something like this:

public class Singleton {

 static Singleton instance;

  public static synchronized Singleton getInstance() {
    if (instance == null)
      instance == new Singleton();
    return instance;
  }

}

The problem with this solution is that synchronized method getInstance() is called every time, while synchronization is actually needed only for the first call of the method (which introduces performance overhead in your application). There were attempts to tackle this problem by using Double-checked locking pattern, which although great in theory didn’t work in practice.

Java and JSON

Fri, 12 Jan 2007 00:00:00 +0000

It seems that JSON vs. XML debate was one of the hot topics for this winter. Again, I think that “vs.” part is sufficient and that both XML and JSON should have their place in overall technology landscape. One of the obvious JSON advantages is that it can be directly evaluated in JavaScript. And for the Ajax-world we live in, it is not a small thing.

For one project, I started looking for a library that would enable me easy transformations between Java and JSON data. JSON in Java looks nice, but what I really want is a more automated and configurable library like those we have for XML processing. My first thought was XStream since I like its simple API, extensible architecture, powerful converters and support for annotations. After first check I found that from version 1.2 on there is a partial support for JSON (which was logical thing to expect). So, currently you can serialize your Java objects to JSON format. Here’s a little example:

Apache XML-RPC 3.0 - No thanks

Fri, 01 Dec 2006 00:00:00 +0000

I have this project that started years ago and still uses old Apache 1.1 version of the XML-RPC library. A few days ago I needed to add an extra functionality to the services it exposes. The underlying API for the new service works a lot with array of objects which is not friendly with that version of XML-RPC library.
The thing is that up until version 3.x of Apache library, Vector and Hashtable were only Java classes that could be used for transferring collections (<array> and <struct> XML-RPC types respectively). So naturally, I thought this was an ideal opportunity to upgrade to 3.x version, which is much better in handling various Java constructs (Object[] among them) as XML-RPC types. This is where surprises started to pop up.

Playing with XFire

Fri, 17 Nov 2006 00:00:00 +0000

Every once in a while I get some WSDL file and a task to create a Java client (and a service for testing purposes) that will use a defined service. I’ve tried XFire a couple of times before (version was 1.1 in those days). But it never actually managed to create stub client and servers classes from “my” WSDL files. So, without much time left to investigate I usually decided to give it a bit more time and fallback to good old Axis. But, a few weeks ago everything changed. I got a definition file and decided to try XFire again. This time I found an Eclipse plugin for it, which does exactly what I needed to do. It needs Java 5 and Eclipse 3.2 … checked and checked … I ran the wizard that plugin provides, entered some basic facts (location of the file, package and the location for the generated sources) and that was all. I was up and running in under five minutes. Excellent. But that is not the end of the story. The real surprise came when I browsed the generated code. It was much more “elegant” (readable) then equivalent Axis stub. With a heavy use of annotations it will be much easier to maintain in the coming years. Also, support for XBeans and Spring definitely makes my life much easier with XFire. I didn’t have time to verify whether it is as efficient as people say, but it doesn’t matter for me at this moment. And with all good coding that has been put into that project, I don’t see how it could be any different. So with all modern features, elegant stub classes and “probably” good performance, I think that I will stick to the XFire for my future SOAP coding.

Retrotranslator

Thu, 02 Nov 2006 00:00:00 +0000

Reading this interview with Jean Elliott, director of product marketing for the Java SE platform at Sun Microsystems, got me into thinking about adoption of Java platform editions among developers (and plain users). I think that 1.4 is still very widely deployed runtime environment out there and that it is the main reason why many developers still hesitate to use Java 5 syntax and features in their projects.

There are three kinds of projects that we can differentiate:

Spring and Flex

Fri, 27 Oct 2006 00:00:00 +0000

In this excellent article Christophe Coenraets gives few examples of how you can use Adobe Flex as a presentation layer for your Spring applications.

It is good to see that my Spring middle-layer classes could be reused with one more presentation technology. I like to have options.

Cross-Domain Ajax support for ActiveMQ

Wed, 18 Oct 2006 00:00:00 +0000

In this post I will try to summarize a case-study for implementing Cross-Domain Ajax support for ActiveMQ.

Use Case
#

In the current implementation of Ajax support for ActiveMQ, you can use JavaScript to consume and send messages, but only directly in your application. This stands mostly due to “same-domain” restriction of the XmlHttpRequest calls.

This makes impossible to use those messages in “trusted” applications and make them all use the same underlying mechanism. For example, you might want to create an embeddable Ajax message browser that could be used in various related applications to allow “operators” (non-technical people) to work with messages in certain queues and topics.

Jetty 6 and XBean

Thu, 12 Oct 2006 00:00:00 +0000

As you probably know, Jetty is a web server (and servlet container) written purely in Java. Because it is small, fast and has a well designed configuration API it is often used as a embedded server in various Java applications (Continuum, FishEye, …).

Of course, when you use Jetty in a Spring-based application, you will want to configure it as you configure the rest of your application (as a Spring bean). Since it has a well defined configuration API, this is not a problem to achieve.

Multiple table generator in Hibernate3

Tue, 26 Sep 2006 00:00:00 +0000

Some time ago I needed a unique identifier generator that will look up a value in a simple name-value kind of database table. Project’s database layer was based on Hibernate2 and since I couldn’t find such a solution I have implemented a MultiTableGenerator which I have blogged about here.

The project was finished and I moved on. Since then, many people reported that my solution was not compatible with Hibernate3 but unfortunately I never found time to fix it. Luckily, I was recently reported that Hibernate team introduced this functionality in Hibernate3. The class is called org.hibernate.id.MultipleHiLoPerTableGenerator. As I can see, it is not documented in the latest version of the reference documentation yet, but you can find a description in a JavaDoc documentation.

Stomp and JSON

Mon, 18 Sep 2006 00:00:00 +0000

As I said in the previous post, one of my main intentions is to use Stomp to send map messages from PHP to Java. So in this iteration, I have added support for JSON encoding/decoding of message content.

Before I dig deeper into new functionalities and changes, let me explain which JSON libraries (PHP and Java) I have used and why.

Dependencies
#

Even though since version 5.2.0, PHP has native support for JSON, I have used pure PHP implementation from Michal Migurski. I did this for only one reason: There is no any restriction to use it in PHP4.

PHP Stomp client

Thu, 14 Sep 2006 00:00:00 +0000

Download
#

This work is based on Hiram Chirino’s excellent library. It would be great if this “extended” version become part of that project too, but for now you can grab it from here.

While the original library is well written, there were few things that prevented me to use it in my project. I started by fixing those things, but then gone too far and now it is quite different from the original, so I’m putting it here.

Tomcat 5.x, Commons Logging and Log4J

Tue, 29 Aug 2006 00:00:00 +0000

First of all, I never use Jakarta Commons Logging (JCL) directly in my applications (Log4J is my tool of choice for logging tasks), but as you probably know many frameworks and libraries do all of their logging through JCL. In most cases you will want to catch some of these log messages, so that you can better monitor your application. For example, you will probably want to log all SQL queries that Hibernate issues, at least in the early development phase, so that you can have a better perspective of what is going on.

Will we have closures in Java 1.7?

Mon, 21 Aug 2006 00:00:00 +0000

It seems like growing interest in dynamic languages will finally move Java syntax toward local functions and closures. Gilad Bracha, Neal Gafter, James Gosling and Peter von der Ah

Java open-source roadmap

Tue, 15 Aug 2006 00:00:00 +0000

It’s finally here. According to news and blogs, Sun announced that it will open source Java ME platform and some components of the SE platform by the end of the year. Sun plans to open source javac compiler and HotSpot virtual machine, two crucial components of the Java SE platform, by the end of the year. The rest of the SE platform should be open sourced during the next year.

They will use some of the proven OSI licenses, but the particular license and governance model is yet to be settled. You can visit the official site for this project and make your contribution to these discussions in the forum.

Handling ADO.NET DataSets with Axis

Mon, 14 Aug 2006 00:00:00 +0000

First of all, SOAP is not my web service protocol of choice since I think it is overkill for the most of applications. I prefer the simplest possible solution for the problem, but when the service that you need is only available through SOAP, you don

On Derby…

Thu, 27 Jul 2006 00:00:00 +0000

There were a lot of discussions lately about inclusion of Derby (aka JavaDB) in the Sun JDK. First of all, I personally think that it will not really change anything.

Parsing form-data multiparts

Wed, 28 Jun 2006 00:00:00 +0000

If you ever needed to parse form-based multipart data, you are probably aware of the Jakarta Commons FileUpload library. But while this library is primarily intended to parse data directly from HttpRequest objects and thus handle uploading of files in your web application, it could be used to parse an arbitrary InputStream and extract multiparts from it too.

As you can probably guess, the part of the library that is related to handling file uploads is well documented, but for the low-level API you can only find the broken example in the JavaDocs. I know that this funcionality is rarely needed, but still it deserves a working example, so here it is.

Syntax support for collections?

Mon, 05 Jun 2006 00:00:00 +0000

It is common to use final static fields to define constants in your Java applications. For example, you will often find the code similar to this in various Java APIs

public class Example {
  public static int one = 1;
}

which is used in the following manner

System.out.println(Example.one);

Of course, Java supports more complex initialization of static properties through static initializer blocks. One of the most common usages for these blocks is initialization of static collections with known values.

XAP proposal in Apache incubator

Fri, 26 May 2006 00:00:00 +0000

There is an interesting Ajax-related proposal in Apache incubator, named XAP (eXtensible Ajax Platform). It is a project donated by Nexaweb Technologies Inc and represents XML-based declarative framework for building rich internet applications based on Ajax. You can find more information about this project on Nexaweb site

In the proposal there is the following paragraph:

Although these toolkits ease development of Ajax-powered web applications, there are still significant development and maintenance challenges, mainly associated with writing, debugging and maintaining JavaScript code. In particular, some developers would prefer not to use JavaScript.

Spring MVC: Exposing cookies to the view

Mon, 01 May 2006 00:00:00 +0000

Recently I needed to display some information on the web page according to the value of a cookie. I think that this is one of the common web application functionalities that have been around for a decade. If you have ever used Spring MVC you know that view resolvers could be instructed to expose request and session attributes as view variables. It is done through the

<property name="exposeSessionAttributes"><value>true</value></property>
<property name="exposeRequestAttributes"><value>true</value></property>

properties in the appropriate view resolver configuration. I wonder why there is no similar functionality for cookies, such as:

DWR 2.0

Wed, 12 Apr 2006 00:00:00 +0000

I just saw the release note for DWR 2.0 milestone 1. It introduces many new features, but the most interesting is certainly “Reverse Ajax”, which allows Java code to asynchronously call JavaScript code in the browser.

I’ve used DWR on few projects in the past and I find it to be a very good AJAX implementation for Java. Also, I can think of some very good use-cases for these new features, so I will certainly put my hands on this new release soon. How about you? What is your experience with DWR and what do you think of these new capabilities?

JUG-NS session

Tue, 11 Apr 2006 00:00:00 +0000

I will be speaking on Quartz scheduler in Novi Sad on April 19th, 2006. The full announcement can be found here (in Sebian).

Apache XML-RPC adapter continued

Fri, 07 Apr 2006 00:00:00 +0000

In the previous post I showed how you can make a Spring wrapper around the WebServer object and thus configure it easily in Spring-based applications. This solution is good for standalone applications that use Spring as a configuration mechanism. But if you are using Spring MVC to develop web applications you probably don’t want to start another web server to handle XML-RPC calls. Instead, we have to find a way to configure XML-RPC to work with the web server that hosts our application and again to use our beans as XML-RPC handlers.

Advanced Configuration of the Spring MVC Framework

Fri, 24 Mar 2006 00:00:00 +0000

OnJava published an article titled Advanced Configuration of the Spring MVC Framework

Apache XML-RPC Adapter for Spring

Mon, 20 Mar 2006 00:00:00 +0000

I tend to use XML-RPC to implement simple requirements for connecting applications. The reason is that it is a simple, straighforward remote-procedure protocol that has good-enough performance for most of such applications. Also, it is very wide-spread so you can find a stable implementation for whatever platform you need it (for example you can use it to connect Java and PHP applications).

When it comes to Java, I use the Apache XML-RPC library (http://ws.apache.org/xmlrpc/). Reasons: it’s been long time in development, it’s stable and I never had any problems with it.

Proper handling of database-related exceptions

Fri, 10 Mar 2006 00:00:00 +0000

This is the issue that I keep running into on various projects, so even if it seems obvious I think it is worth spending a post on it.

Some OR mapping frameworks tend to use batch update operations when dealing with the database. The “problem” that this approach introduces is that if any problem occurs during the update, a java.sql.BatchUpdateException exception will be thrown instead of the regular java.sql.SQLException. If we don’t handle BatchUpdateException properly the message it will give us will not be very useful.

SMS-Powered applications

Wed, 09 Jun 2004 00:00:00 +0000

onJava.com published an article on texting with Java

Hibernate MulitpleTableGenerator

Sun, 06 Jun 2004 00:00:00 +0000

This key generator is designed to enable Hibernate to generate unique keys using the table structure like this one

The keys that you get from database can be used directly or with HiLo algorithm (use MultipleTableHiLoGenerator class in that case).

Job Scheduling in Java

Wed, 10 Mar 2004 00:00:00 +0000

onJava.com published article on job scheduling with Java and Quartz

Quartz recent jobs patch

Mon, 01 Dec 2003 00:00:00 +0000

Introduction
#

This patch is made for Quartz 1.2.3

Java job scheduler and it extends original Scheduler interface with getExecutedJobs() method that returns list of recently executed jobs. Size of the list is configurabile with org.quartz.scheduler.executedJobsListSize parameter in property file (quartz.properties). It could be also turned off by specifying value 0 or by deleteing this entry from the property file. This patch works even for volatile Jobs and Triggers and doesn’t use database.

Quartz recent jobs patch

Mon, 01 Dec 2003 00:00:00 +0000

This patch is made for Quartz 1.2.3

Introduction to Version Control with CVS

Wed, 12 Nov 2003 00:00:00 +0000

php|architect published introductory article on version control with CVS

Quartz XML-RPC plugin

Sat, 01 Nov 2003 00:00:00 +0000

Quartz is a powerful job scheduling system for Java. Here you can find a XML-RPC plugin that can enable you to use the Quartz as a web service using XML-RPC protocol. You can use this plugin for accessing Quartz API from other languages than Java, such as PHP for example. Also, you can use it from your distributed Java application if you find this way more appropriate than RMI.

Introduction to Bug Management

Mon, 08 Sep 2003 00:00:00 +0000

php|architect published introductory article on Bug management

Scripting the enterprise

Tue, 08 Jul 2003 00:00:00 +0000

In the beginning …
#

PHP was designed as scripting language used to develop Web based applications. Because of its flexibility, extensibility and ease of use it became widely popular among developers, and pretty fast the large community was created. As time was passing, people wanted to develop more complex applications with it, but PHP was designed for page centric architecture with very limited support for object-oriented programming. Also, there was no system support for transactions, caching, software components and all the other things that developers of the enterprise applications have used to have. There was no application container that would take care of all the system staff that we need in our applications, so that we can focus on business requirements. As applications are getting larger and more complex scalability becomes a new issue. PHP does not scale well and there is no easy and standard way to make a cluster to achieve better scalability. So, PHP applications (with respectable exceptions) were left in the area of small and middle complex web applications.

Arno

Thu, 05 Jun 2003 00:00:00 +0000

Introduction
#

This is version 0.1 of small application that demonstrates how to use EJB technology and Struts web development framework together. It is a personal organizer that let’s its users to manage their tasks and events. Don’t expect high usability of this software (in some future versions it will be considered) because it is only ment to be a demo.

Apache XMLRPC 1.1 authentication patch

Tue, 31 Dec 2002 00:00:00 +0000

When you are using XML RPC, you often want to have some security mechanism that will protect your system from malicious users.

One mechanism that could be used is basic HTTP authorization. When this approach is used username and password from the client are sent as a plain text in the HTTP header of the request. If authorization is valid, server will process the request or send response with status code 401 which means that client has not been successfully authorized. You may argue that plain text as a transport is not secure enough, but you can always use this mechanism with SSL what will give you more secure system.

PHP Iterator

Mon, 11 Nov 2002 00:00:00 +0000

PHP arrays are generally very powerful object container. But still, we can easily add a little more fuel to them. Imagine Iterator object that is a kind of wrapper around our arrays. What we will try to accomplish here is to create unique interface for traversing arrays and to add a little more control over how our objects are created and finally, to support lazy loading.

Posts on Dejan Bosanac

Master your skills

Messaging for IoT

ActiveMQ and HawtIO

MQTT over WebSocket transport in ActiveMQ

Lightweight Messaging For Web And Mobile With Apache ActiveMQ

Apache ActiveMQ 5.7.0 released

Pluggable ActiveMQ Storage Lockers

Messaging Anti-Patterns: Part 3

Using appropriate message type #

Messaging Anti-Patterns: Part 2

Short-lived connections #

Messaging Anti-Patterns: Part 1

Conference week wrap-up

ActiveMQ 5.6.0 and other news

ActiveMQ in the cloud

New ActiveMQ failover and clustering goodies

ActiveMQ networks and advisory messages explained

Advanced messaging with Apache ActiveMQ slides

JEEConf Session

Just arrived!

ActiveMQ in Action released

ActiveMQ 5.5: Audit Logging

Software scalability | Belgrade meetup 04

How to monitor ActiveMQ networks

ActiveMQ in Action in Production

ActiveMQ 5.4.1: Encrypted passwords

What's new in Apache ActiveMQ 5.4.0

Fast producer failover with ActiveMQ

ActiveMQ 5.4: Seamless OSGi Integration

Software scalability | Belgrade meetup

Securing ActiveMQ 5.3.1 console

ActiveMQ 5.3.1 Released

ActiveMQ 5.4: Stomp over Web Sockets

ActiveMQ producer flow control with timeout

Jettison 1.2 Released

Handling IOException in ActiveMQ

Fuse Stomp project

Python messaging: ActiveMQ and RabbitMQ

Apache ActiveMQ 5.3.0 Released

XML to JSON

Wire format negotiation timeout and log4j jms appender FAQs

Stomp Future

pyactivemq on Ubuntu

ActiveMQ in Action MEAP update

Fuse Message Broker 5.0.0.28 released

ActiveMQ OSGi integration

Fuse Message Broker 5.3.0.2 released

Fuse Message Broker 5.0.0.27 released

Fuse Message Broker 5.3.0.1 released

Jettison 1.1 released

ActiveMQ continuos intergration

Asynchronous messaging for web sites

ActiveMQ in Action discount

Fuse Message Broker 5.0.0.26 released

Unacking messages with Stomp

Fuse Message Broker 5.2.0.2 released

New chapters of ActiveMQ in Action are available online

Message groups just got a bit better

Sending over failover transport with timeout

Apache ActiveMQ 5.2

Stomp v1.1 thoughts

Jettison in practice

links for 2008-08-11 [delicious.com]

ActiveMQ in Action

links for 2008-07-21

Jettison 1.0.1 released

links for 2008-04-10

links for 2008-04-04

Indexing repositories

links for 2008-03-18

links for 2008-02-25

Customizing Enums

links for 2008-02-08

Jettison 1.0 RC3 Snapshot

links for 2008-01-17

links for 2008-01-09

links for 2008-01-04

Dealing with large code bases

Securing Stomp

Using appropriate message type
#

Short-lived connections
#

Use Case
#

Dependencies
#

Download
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