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"At this point, the only source of useful overview documentation for the Common Navigator are the excellent tutorials at Michael Elder's (the author of the CN) blog. Soon I hope to get some of this transferred into the Eclipse Plugin Developer's Guide. RCP applications can quickly and easily use the CN to show the resources in the workspace. This assumes that your RCP application uses resources (which is another discussion). The CN can also be used for non-resource RCP applications, in that case, these instructions don't apply, as the objects treated by the CN have to be created directly by the RCP application. If you are planning to use the CN in an RCP application that uses resources, there are 3 (2 of which are completely undocumented) things you must do:"

When you write Eclipse plug-ins sooner or later you will start thinking about testing your work. The very first steps will lead you to the Internet. But to my (and maybe your ;) ) surprise this information is not very easy to find. I know two ways to accomplish this task and I want to describe the first one - testing Eclipse plug-ins using build-in JUnit support.

There are many approaches available to scale PostgreSQL beyond running on a single server. An outline of the terminology and basic technologies involved is at High Availability and Load Balancing. There is a presentation covering some of these solutions. There is no one-size fits all replication software. You have to understand your requirements and how various approaches fit into that. For example, here are two extremes in the replication problem space: You have a few servers connected to a local network you want to always keep current for failover and load-balancing purposes. Here you would be considering solutions that are synchronous, eager, and therefore conflict-free. Your users take a local copy of the database with them on laptops when they leave the office, make changes while they are away, and need to merge those with the main database when they return. Here you'd want an asynchronous, lazy replication approach, and will be forced to consider how to handle conflicts in cases where the same record has been modified both on the master server and on a local copy. These are both database replication problems, but the best way to solve them is very different. And as you can see from these examples, replication has a lot of specific terminology that you'll have to understand to figure out what class of solution makes sense for your requirements. A great source for this background is in the Postgres-R Terms and Definitions for Database Replication. The main theoretical topic it doesn't mention is how to resolve conflict resolution in lazy replication cases like the laptop situation, which involves voting and similar schemes.

"The concept of automatic incremental compilation is not familiar to many developers. A very frequent question from Eclipse beginners is, "where is the compile button?" The answer is that an IDE with automatic compilation doesn't need a compile button. Every time you make a change to a file, or a group of files, the incremental builder immediately rebuilds every source file that was affected by the change. In this environment, the idea of compilation as a task the user is involved in disappears -- the world is just always in a compiled state. So what magic goes on behind the scenes to make this happen? How does the Java™ builder know which files need to be recompiled when a given source file changes? This is no easy task, but in broad brush strokes, this is what the Eclipse Java builder does: "

Caching is the most important performance optimization technique. There are many things that can be cached in persistence, objects, data, database connections, database statements, query results, meta-data, relationships, to name a few. Caching in object persistence normally refers to the caching of objects or their data. Caching also influences object identity, that is that if you read an object, then read the same object again you should get the identical object back (same reference). JPA 1.0 does not define a shared object cache, JPA providers can support a shared object cache or not, however most do. Caching in JPA is required with-in a transaction or within an extended persistence context to preserve object identity, but JPA does not require that caching be supported across transactions or persistence contexts. JPA 2.0 defines the concept of a shared cache. The @Cacheable annotation or cacheable XML attribute can be used to enable or disable caching on a class.

"Apache Tuscany simplifies the task of developing SOA solutions by providing a comprehensive infrastructure for SOA development and management that is based on Service Component Architecture (SCA) standard. With SCA as it's foundation, Tuscany offers solution developers the following advantages: Provides a model for creating composite applications by defining the services in the fabric and their relationships with one another. The services can be implemented in any technology. Enables service developers to create reusable services that only contain business logic. Protocols are pushed out of business logic and are handled through pluggable bindings. This lowers development cost. Applications can easily adapt to infrastructure changes without recoding since protocols are handled via pluggable bindings and quality of services (transaction, security) are handled declaratively. Existing applications can work with new SCA compositions. This allows for incremental growth towards a more flexible architecture, outsourcing or providing services to others. In addition, Tuscany is integrated with various technologies and offers: a wide range of bindings (pluggable protocols) various component types including and not limited to Java, C++, BPEL, Spring and scripting an end to end service and data solution which includes support for Jaxb and SDO a lightweight runtime that works standalone or with other application servers a modular architecture that makes it easy to integrate with different technologies and to extend Integration with web20 technologies Apache Tuscany SCA is implemented in Java and C++ (referred to as Native)"

" Over the past few years, and actually the past year, a lot of new initiatives have surfaced in the area of creating so called language workbenches - aiming at facilitating the definition and use of DSLs and code generation. We believe each of these has its own strengths and weaknesses, and none is 'the best' for every purpose. Still, a lot of people keep asking for the best workbench. Based on that, we are now planning to have a Language Workbench Competition, in which we will be able to compare the strengths and weaknesses of these workbenches based on solutions for a predefined set of cases. Keep an eye on this page for more details in the coming, as the cases are being defined and the possibilities of co-hosting this initative at Code Generation 2011 in Cambridge are being investigated."

Imagine a scenario where you have some Word documents created in MS Word and you want to display them in your web application. So how would you view the content of the file? A suitable and easy solution is if you could get the HTML form of the Word document then it can be viewed in the web browser within your application. Isn't it great when you could view the documents without having installed some Office viewer? Let's now find out how did we make use of HTML format in making GroupDocs.Assembly more powerful and useful for you. Since version 19.5, the assembled Word Processing documents, Spreadsheets, Presentations, and Email files could be saved as HTML with external resources. This means that the generated reports can now be saved as HTML files along with the resources such as images and, as I have mentioned before, you would be able to embed and view the content of the generated reports within your web application. Read more - https://bit.ly/2WRtqqc

There is no migration system in vanilla grails (although possibly in Grails 2.0 …. ?) but there do exist several plugins that provide  some migration functionality. As of this post I am aware of three: dbMigrate, Liquibase, and Autobase. Of these, I prefer Liquibase and cannot recommend it enough. While it uses XML to describe its changesets it is a mature open-source Java project that works flawlessly (and has some excellent documentation). I did not have much luck using DbMigrate and Autobase when including in an existing project… which is a shame as Autobase (which is built on Liquibase) uses a nice DSL syntax to build the migrations.

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Setting up an infrastructure for Instant Messaging" article series. In my previous tutorials, I showed you how to setup the Openfire IM Server and how to configure the Spark client in order to connect to that server. In this tutorial, I will show you how to add XMPP messaging capabilities to your own application. I will use the Smack library, an Open Source XMPP (Jabber) client library for instant messaging and presence. Smack is a pure Java library and can be embedded into your applications to create anything from a full XMPP client to simple XMPP integrations.

Last weekend while pondering the question "Is Scala ready for the enterprise?" I decided to write a simple Java EE 6 app entirely in Scala, without using any Java. I had three main reasons for doing this: one was just to see how easy/difficult it would be to write everything in Scala (it was easy).  Another was to document the process for others journeying down the same road (the entire project is on github).  Finally, I wanted to identify advantages of using Scala instead of Java that are specific to Java EE apps (I found several). Background The specific app I created was an adaptation of the Books example from Chapter 10 of Beginning Java™ EE 6 Platform with GlassFish™ 3. It's a simple web app that displays a list of books in a database and lets you add new books. Although it's a pretty trivial app, it does touch on several important Java EE 6 technologies: JPA 2.0, EJB 3.1 and JSF 2.0.

I am working on a web site that will help students practice their Scala programming skills. As I labored along, writing my JSF app code, I thought "this is silly-why not practice Scala at the same time?" But I like JSF and wasn't ready to jump to Lift or Vaadin. With Eclipse, this isn't all that hard. Install the Java plugin. Make a dynamic web project in the usual way, using the Java EE perspective. Then, switch to the Scala perspective, right-click on the project, and, if all planets are aligned correctly, you will get a menu item "Add Scala nature". (If they are not, see here for a manual approach.) Add your managed beans as Scala classes. Finally, switch back to the Java EE perspective, select the project properties, and add the Scala library JAR as a Java EE module dependency. But I like NetBeans and wasn't ready to switch to Eclipse. (Unfortunately, JSF 2 support in Eclipse is pretty minimal, the Glassfish integration is a bit flaky, and the Scala plugin has very little usable code completion.) NetBeans doesn't let me add a "Scala nature" to a web project. If I add Scala files to the project, I can edit them with the Scala editor, but they just get copied to the WAR file, without any compilation. I had one look at the Ant scripts for a Scala and a web project and decided that I wasn't going to figure out how to merge them. This blog shows how you can use Maven to make a mixed Scala/Java project in NetBeans. So I gathered up JSF and Scala pom.xml files from here and here, cut out the considerable crud from the JSF POM file that was probably meant for supporting Tomcat, and merged the results to the best of my ability-see below. You use the usual Maven directory structure, but with a src/main/scala directory instead of src/main/java:

The aim of this paper is a brief introduction to MDA technology and a summary / comparison to the approachments to MDA of AndroMDA and Acceleo, intending to be a practical and understandable summary Introduction Model-driven architecture (MDA) is a software design approach for the development of software systems. It provides a set of guidelines for the structuring of specifications, which are expressed as models. It was launched by the Object Management Group (OMG) in 2001 The Model-Driven Architecture approach defines system functionality using a platform-independent model (PIM) using an appropriate domain-specific language (DSL). One of the main aims of the MDA is to separate design from architecture. As the concepts and technologies used to realize designs and the concepts and technologies used to realize architectures have changed at their own pace, decoupling them allows system developers to choose from the best and most fitting in both domains. The design addresses the functional (use case) requirements while architecture provides the infrastructure through which non-functional requirements like scalability, reliability and performance are realized. MDA envisages that the platform independent model (PIM), which represents a conceptual design realizing the functional requirements, will survive changes in realization technologies and software architectures.

Gaelyk is a lightweight Groovy toolkit for Google App Engine Java. Gaelyk lets you deploy small applications on Google App Engine Java. Gaelyk gives you the choice to use Groovy for developing your applications. Gaelyk builds upon Groovlets. and the Groovy template servlet Gaelyk allows you to cleanly seperate your views with Groovy templates and your actions in Groovlets. Gaelyk simplifies the usage of the Google App Engine SDK by providing more concise and more powerful shortcuts when using the datastore, memcache, the blobstore, the images service, the URL fetch service, when sending and receiving emails or Jabber messages, and much more. Gaelyk lets you define friendly REST-ful URLs thanks to its URL routing system Gaelyk provides a simple plugin system for improving code reuse and code sharing You can: download Gaelyk in the download area, learn how to create Gaelyk applications by reading the extensive tutorial, and participate in the community.

In this article I'll describe the setup I use to do develop Lift applications. While more heavy-weight than if an interpreted language is used, I find this setup provides fairly decent turnaround times. So, it took a little longer than expected to write this article which continues where the previous stopped. But all good things come to he who waits The software used in the previous article all had major updates in the meantime: Scala 2.8 (2.8.1 is just around the corner) Eclipse 3.6 Scale IDE for Eclipse (though a nightly build is currently needed for Eclipse 3.6) Gradle 0.9 RC1 Lift 2.1 RC2

Last week I decided to challenge Scala's downscalability by trying to replace a Groovy script with a Scala pendant. In this article you will read about this little experiment and a comparision of the Scala result with the Groovy predecessor. But first some background about the script: Some time ago my company introduced a new spam notification system.  When it thinks that a mail contains spam, it keeps it in quarantine and once or twice a day sends an email to the recipient (me) reporting all the kept mails, together with an intranet web link for each  to release it. Here you see an example of such a mail (note: I have my mails displayed in plain text format):

The Fornax-Platform is a development platform for tools related to the Model-Driven-Software-Development - MDSD. In this context tools are cartridges, transforms, ready-to-use generators or simple enhancements to make it easier to work in a MDSD environment. Another approach is to provide Howto's and tutorials that simplify the undestanding of MDSD. The Fornax-Platform provides infrastructure and tools to simplify the management and the development of such components and tools. It is independent from companies in this area of software development.

"Besides a rich user interaction many applications need to display a big amount of data sets as diagrams or reports as part of their applications. In order to bridge the gap the BIRT project was created as part of the eclipse ecosystem. BIRT is an open source Eclipse-based reporting system that integrates with your Java/J2EE application to produce compelling reports. That BIRT integrates well with classic RCP applications is a well known fact. But the need for rich internet applications is still growing. And here the RAP comes into play. As a platform for developing Web 2.0 applications with the same patterns as for RCP it paves the way for single sourcing applications running on both platforms. In this talk we will show how to integrate diagrams and reports known from BIRT into RAP applications. Topics covered include how to setup the environment to let BIRT and RAP play well together. In addition we will give advices how to use the reports inside RAP applications and which problems may arise. As a final outcome of we will know everything to bring reporting capabilities into RAP applications. "