In addition to building Web and console applications with Ruby, you can write complex GUI desktop applications that run unmodified on multiple platforms. Thanks to JRuby, a robust alternative to the traditional C implementation of Ruby, Ruby GUI toolkits can use UI tools available to the Java platform. This article introduces Monkeybars, a library that uses JRuby and Swing for building applications, and takes you through an example application.

Although many development teams use version-control systems to manage code changes, they can struggle when developers code off the same code base, in parallel. In this Automation for the people installment, automation expert Paul Duvall shows how to effectively tag, branch, and merge source code using the open source, freely available Subversion version-control system.

The multitenant nature of Software as a Service (SaaS) applications makes security an essential concern. This article introduces a viable and practical approach to securing a multitenant Java application with the open source Spring Security framework combined with Apache Directory Server. The authors present a multitenant example Web application to demonstrate this approach.

The latest release of the IBM JRE for Java SE 6 enhances IBM's class sharing feature first introduced in Version 5. In this article, performance analysts Adam Pilkington and Graham Rawson detail the changes, which include improvements in application startup times and memory utilisation.

In Part 2 of this brief series, Bilal Siddiqui explains how to use BPEL to express the logic of configurable business workflows. You'll learn how to host your BPEL applications on a BPEL engine and make them work in conjunction with an IoC implementation.

The WebSphere sMash environment enables rapid development of interactive Web applications based on popular Web technologies such as PHP, and it lets you reuse existing Java assets from PHP scripts. This article introduces the Java Bridge and shows how to access Java classes from PHP.

The session state management mechanism provided by the Servlets framework, HttpSession, makes it easy to create stateful applications, but it is also quite easy to misuse. Many Web applications that use HttpSession for mutable data (such as JavaBeans classes) do so with insufficient coordination, exposing themselves to a host of potential concurrency hazards.

We live in the era of mashups. Creating Web pages that give users the information they want is a good start, but offering a source of raw data that other Web developers can easily mix in with their own applications is better. In this installment of Mastering Grails, Scott Davis introduces various ways to get Grails to produce XML instead of the usual HTML.

Start with a Java applet and build a server-based proxy system that uses your browser to access an arbitrary Web service. You'll use JavaScript code to access applet-based information and call a servlet, which retrieves the remote information. Thus, you bypass the same-server restrictions on what an applet can and cannot do.

This article explains how you can improve the performance of I/O-intensive Java applications running on Linux and UNIX platforms through a technique called zero copy. Zero copy lets you avoid redundant data copies between intermediate buffers and reduces the number of context switches between user space and kernel space.

Domain-specific languages have become a hot topic; much of the buzz around functional languages is their applicability to build such languages. In this, the eighth article in The busy Java developer's guide to Scala, Ted Neward starts building a simple calculator DSL that demonstrates the power of functional languages for building "external" DSLs. Toward that end, he explores a new feature of Scala, case classes, and revisits an old functional friend, pattern matching.

Apache XMLBeans does not inherently support multiple versions of an XML schema. For applications that need this type of support to manage compatibility, this limitation is serious. But there is a solution, and in this article, you'll learn how dynamic class loading techniques can help.

Elliotte Rusty Harold demonstrates Java 5's new XPath API.

This tutorial takes you beyond the basics of the JAX-RPC and shows how to customize your JAX-RPC Web services and clients with the help of Apache Axis. On the client side, you can autogenerate much of the code required to connect with new JAX-RPC Web services, focusing your time on the interactions themselves rather than on routine Web service calls. On the server side, you can add additional options, limit the methods you expose, and restrict parameters you'll accept. All of this is possible with a little customization and a deeper understanding of the Apache Axis toolset.

Get started with configuring, testing, and modifying the Universal Services.

pureQuery is a high-performance Java data access platform focused on simplifying the tasks of developing, managing and optimizing applications and services that access data. It consists of tools, APIs and a runtime engine. The previous articles in this series introduced the two programming styles to help users access the database through simple but powerful APIs. This article summarizes some best practices for development using the pureQuery API and gives you real-world scenarios to see how to implement these practices.

The third and final installment in this series on run-time monitoring of Java applications focuses on strategies and techniques for monitoring the performance and availability of an application's supporting and dependent services. These include the underlying host operating system, the operational database, and messaging infrastructures. The article concludes with a discussion of performance data management issues and data reporting and visualization.

Everything in Grails, from build scripts to individual artifacts such as domain classes and controllers, throw events at key points during an application's life cycle. In this Mastering Grails installment, you'll learn how to set up listeners to catch these events and react to them with custom behavior.

Download and try the IBM Cognos Validation tool, a command line utility written in Java using the IBM Cognos SDK. This tool can run a complete validation check of all the reports in the Content Store by automating the Report Studio validate process.

This article explains how to use IBM Rational Software Architect v7.0 to develop Ajax-supported JSF components.

Part 1 of this three-part series on run-time monitoring of Java applications focuses on the JVM's health and ways to instrument source code to capture performance metrics. This second installment presents techniques for instrumenting Java classes and constructs without modifying the original source code.

Databases are often out of sync with the applications they support, and getting the database and data into a known state is a significant challenge to manage. In this installment of Automation for the people, automation expert Paul Duvall demonstrates how the open source LiquiBase database-migration tool can reduce the pain of managing the constant of change with databases and applications.

Get the details on how to use the common SQL API (CSA), a set of stored procedures that exist across all IBM data servers. Learn to employ the common SQL API and integrate it in an application. Explore a small J2EE Web application, based on the common SQL API, that compares the subsystem parameters of two IBM DB2 for z/OS subsystems by employing the GET_CONFIG CSA stored procedure.

Run-time performance monitoring is critical to achieving and maintaining a well-performing system. In this article, the first in a three-part series, Nicholas Whitehead explains how to do low-level granular monitoring of Java performance efficiently. The data you generate can provide valuable insights into system operation and reveal constraints and influences that affect an environment's stability and performance.

JavaServer Pages (JSP) and JavaServer Faces (JSF) used to have different variants of the Expression Language (EL). Their unification in JSP 2.1 opened new possibilities, allowing you to use deferred values and deferred method attributes in your custom JSP tags. This article shows how to develop Java Web components based on JSP tag files, which are much simpler and easier to build than the JSF components.

In the real world, code has to be referenced and packaged. In this installment of The busy Java developer's guide to Scala series, Ted Neward covers Scala's package and access modifier facilities before continuing to explore of the functional side of Scala by examining the "apply" mechanism.

This article introduces using the Ruby Development Tools (RDT) plug-in for Eclipse, which allows Eclipse to become a first-rate Ruby development environment. Ruby developers who want to learn how to use the rich infrastructure of the Eclipse community to support their language will benefit, as will Java developers who are interested in using Ruby.

XML serialization has a myriad of uses, including object persistence and data transport. However, some XML-serialization technologies can be complex to implement. XStream is a lightweight and easy-to-use open source Java library for serializing Java objects to XML and back again. Learn how to set up XStream, and discover how to use it to serialize and deserialize objects as well as to read configuration properties from an XML configuration file.

Representational state transfer (REST) is a style of designing loosely coupled applications that rely on named resources rather than messages. The hardest part of building a RESTful application is deciding on the resources you want to expose. Once you've done that, using the open source Restlet framework makes building RESTful Web services a snap. This tutorial guides you step-by-step through the fundamental concepts of REST and building applications with Restlets.

XML parsing is a part of nearly every enterprise application. Error handling, though, is absent from most of those same applications. Learn how to use the Simple API for XML (SAX) to deal with errors in your XML parsing -- even if your applications are using the DOM, JAXP, or another API to deal with XML.

In the first part of this series, you saw how to generate JavaScript code for sending Ajax requests and processing Ajax responses. The second part showed how to create HTML forms, using conventions and JSP tag files to minimize setup and configuration. In this third part of the series, you'll learn how to develop client-side validators based on JavaScript as well as server-side validators, which are implemented as JSP tag files backing up their JavaScript counterparts. You'll also learn how to use resource-bundles that are reloaded automatically when changed, without requiring the restart of the application.

Remote procedure calls (RPCs) are the precursors to modern Web services that are based on the Simple Object Access Protocol (SOAP) or Representational State Transfer (REST). Because all of the Java platform's Web service APIs are built on the concepts introduced in RPC, understanding the Java APIs for XML-Based RPC (JAX-RPC) is an almost mandatory step for writing efficient and effective Web services in the Java language. This tutorial takes you through getting and installing JAX-RPC, configuring it, and building a server-side RPC receiver and a simple client-side application.

In this Mastering Grails installment, Scott Davis explores the various ways that Grails can use database tables that don't conform to the Grails naming standard. If you have Java classes that already map to your legacy databases, Grails allows you to use them unchanged. You'll see examples that use Hibernate HBM files and Enterprise JavaBeans 3 annotations with legacy Java classes.

If you've been curious about the new release of WebSphere Customer Center (now named IBM InfoSphere Master Data Management Server), then this series is for you! This series describes how and why pureQuery technology was used in the new release, the implementation and migration to pureQuery, and the results of performance and capability testing to validate this critical decision. Part 2 focuses on our productivity and performance measurements in making the decision to user pureQuery and also provides some hints and tips for working with pureQuery.

XPath makes selecting elements, attributes, and text in an XML document easy. Learn how to evaluate XPaths from Java programming, and work with the returned nodes.

Refactoring is a well-accepted practice for improving existing code. Yet, how do you find the code that should be refactored, in a consistent and repeatable manner? In this installment of Automation for the people, you'll learn how to use static analysis tools to identify code smells to refactor, with examples showing how to improve odiferous code.

Inversion of Control (IoC) and Web Services Business Process Execution Language (WS-BPEL) can be effective tools for implementing dynamic business workflows. In this article, the first in a two-part series, Bilal Siddiqui describes business workflows' dynamic nature and proposes a two-layer workflow model that lets you use XML to build configurable and flexible solutions.

If you've been curious or confused about the new release of WebSphere Customer Center (now named IBM InfoSphere Master Data Management Server), then this series is for you! This series describes how and why pureQuery technology was used in the new release, the implementation and migration to pureQuery, and the results of performance and capability testing to validate this critical decision. Part 1 focuses on the evaluation of persistence mechanisms and our plan to validate the technology.

Wildcards can be very confusing when it comes to generics in the Java language, and one of the most common mistakes is to fail to use one of the two forms of bounded wildcards ("super T" and "? extends T") when needed. You've made this mistake? Don't feel bad, even the experts have, and this month Brian Goetz shows you how to avoid it.

Objects have their place in Scala, but so do functional types such as tuples, arrays, and lists. In this installment of Ted Neward's popular series, you'll begin to explore the functional side of Scala, starting with its support for types common to functional languages.

pureQuery is IBM's new platform within Data Studio for developing Java database access applications. Its simple API and integrated tooling make data access developers more productive and encourages coding best practices for improved performance. Spring is an open source Java/J2EE application framework that offers higher level data access features like transaction management, resource management, and Data Access Object hierarchies which, when integrated with pureQuery, lead to a simpler application development and maintenance experience. This tutorial guides you in creating a pureQuery application that uses the Spring Framework's Data Access features.

Program performance is always a concern, even in this era of high-performance hardware. This article, the second in a two-part series, covers the statistics of benchmarking and offers a framework you can use to benchmark Java code ranging from self-contained microbenchmarks to code that calls a full application.

Program performance is always a concern, even in this era of high-performance hardware. This article, the first in a two-part series, guides you around the many pitfalls associated with benchmarking Java code. Part 2 covers the statistics of benchmarking and offers a framework for performing Java benchmarking. Because almost all new languages are virtual machine-based, the general principles the article describes have broad significance for the programming community at large.

Part 1 of this tutorial gave you a foundational understanding of XPath. Using slash notation, wildcards, unions, and simple text, you learned how to locate elements and attributes anywhere within an XML document. However, sometimes you need more than just matching based on the name of a node. Predicates give you advanced and refined searching capabilities, allowing you to evaluate the values of attributes and the parent and child nodes of a targeted element. Rather than find a wider node set and refine or filter that set programmatically, you can add predicates to your XPaths to find exactly the nodes you want.

The number of cell phone users worldwide is at 3.3 billion and rising, and Internet access from mobile phones is on a rapidly upward trajectory. Developing for the mobile Web has its unique demands. In this Mastering Grails installment, Scott Davis shows you how to make your Grails applications mobile phone friendly.

XML is a data format concerned primarily with compatibility and flexibility. But as useful as XML is, it's limited without the abilities to find specific portions of a document quickly and to filter and selectively locate data within a document. XPath provides the ability to easily reference specific text, elements, and attributes within a document -- and with a fairly low learning curve. Additionally, XPath is key to many other XML vocabularies and technologies, such as XSL and XQuery. This tutorial will teach you the fundamentals of XPath, including all of its various selectors and semantics, in an example-driven and hands-on manner.

Project documentation is often one of the necessary evils in delivering a software product. But imagine being able to generate your documentation at the click of a button. In this installment of Automation for the people, automation expert Paul Duvall explains how you can use open source tools to automate the generation of Unified Modeling Language (UML) diagrams, build figures, entity-relationship diagrams (ERDs), and even user documentation.

The Ruby Java Bridge (RJB) lets you load Java classes directly to, and call them from, Ruby on Rails applications. This tutorial shows how you can put this toolkit to work by reusing your legacy Java Web application code in a modern Web development platform.

The open source World Wind Java (WWJ) SDK by NASA creates new possibilities for the open Geographic Information Systems (GIS) community. World Wind, a 3D interactive world viewer written in the Java language and OpenGL, lets users zoom from outer space into any place on Earth. This article explains how GIS developers who want to enhance their Eclipse-based applications can embed the WWJ SDK as an Eclipse plug-in.

Scala gives you just as much support for implementation inheritance as the Java language does -- but Scala's inheritance yields a few surprises. This month, Ted Neward introduces you to polymorphism done the Scala way, blending functional and object-oriented language styles while still mapping perfectly to the Java platform's inheritance model.