"The Jakarta Commons project encompasses several subprojects, which contain reusable Java components. Of these, the Logging, Validator, and Digester subprojects are the best known, if only because Struts uses them. A fairly new Commons subproject, still in development, is Chain. The Chain framework is an implementation of the Chain of Responsibility pattern, used to execute a flow of sequential process steps. In the near future, Chain will also be used by Struts (not entirely coincidental—some Struts committers are also Chain committers)."
"Note: Jakarta Commons is different from Apache Commons. The latter is a top-level project of the Apache Software Foundation. The former is a subproject of the top-level Jakarta Project, and the subject of this article. Furthermore, Jakarta Commons is solely based on the Java language. In this article, whenever I say Commons, I am referring to Jakarta Commons."
"Jakarta Ant has become a widely accepted standard for Java project build automation. It is not only a tool, but also a very powerful language that allows you to describe complex build and deployment scenarios. At the same time, it is not a scripting language, but a process-oriented language. The convenient thing about Ant is that it's XML-based, so you can easily generate and edit its build files with lots of tools. And finally, Ant is also an open platform and a framework allowing you to plug in new functionality. All of these things make Ant more than suitable for the role of a general purpose automation tool."
"Lucene is a Java library that adds text indexing and searching capabilities to an application. It is not a complete application that one can just download, install, and run. It offers a simple, yet powerful core API. To start using it, one needs to know only a few Lucene classes and methods."
"Jakarta Commons is a Jakarta subproject that creates and maintains independent packages unrelated to any other framework or product. The packages are a collection of components that serve small, useful purposes in their own right, and are usually server-centric."
"Base64 encoding is primarily used in the transfer of email. The RFC that defines the transfer of MIME documents specifies Base64 encoding, so that arbitrary binary data can be transferred safely using only the printable ASCII character set. For example, if you have an image that needs to be transferred using email, your email client will use Base64 encoding to convert this binary data into ASCII. Using this encoding, triplets of 8-bit octets are encoded as groups of four characters, each representing 6 bits of the source 24 bits. The encoded string is 1.3 times the size of the original. The = character is used to pad the end of the file. Besides MIME documents, this encoding is also used for encoding the user:password string in an HTTP Authorization header in BASIC Authorization."
"I develop and teach Java courses, some of which require specific versions of tools like Ant, Xalan, and Tomcat. I normally provide the lab administrators with a readme file explaining how to install each tool, but this approach sometimes fails. For example, I may decide to use a newer version of Tomcat at the last minute, or the person installing the software may install the wrong version of a critical tool."
"OJB can be downloaded from the Apache Jakarta Project home page. We will use version 0.9.7, the latest as of this writing, throughout this article. As a member of the Jakarta family, OJB makes extensive use of the Jakarta Commons Library. This is good news to everyone who is already familiar with the Commons library through other Jakarta projects like Struts."
"This article briefly describes the Jakarta Avalon project and defines the steps required to specify, implement, package, and deploy an application for the Jakarta Avalon Phoenix v4.0a4 application server."
"The Jakarta Digester framework grew out of the Jakarta Struts Web toolkit. Originally developed to process the central struts-config.xml configuration file, it was soon recognized that the framework was more generally useful, and moved to the Jakarta Commons project, the stated goal of which is to provide a "repository of reusable Java components." The most recent version, Digester 1.3, was released on August 13, 2002."
"So there you have it. Hours of coding (not to mention debugging) saved by using one of the many available taglibs from the Jakarta project. As you can see, there are many available taglibs, and chances are some of them have tags that you probably could use in your current applications that use JSP. So why reinvent the wheel? Post your comments"
"This article delves deep into the guts of Slide's transactional storage system. Guided by samples from real code, you can see how simple transactional caching might work and what issues need to be addressed. Based on this, you will learn how locks are used in Slide's transactional file system to get full ACID transactions."
"Jakarta Commons Net is a feature rich protocol factory that allows developers to write applications that require high level protocol access. This excerpt from the Jakarta Commons Online Bookshelf module 3 explains the building blocks of these protocols and then discusses the NET API, with a few protocol API examples."
"Mark Carges, CTO of BEA began by talking about it?s focus on Enterprise Java, and took a very different spin from most of the other keynotes. Looking at where innovations are occurring in Enterprise Java, ?aside from the IDE?s itself, the single biggest thing for productivity has been around application frameworks?."
"This article, the first of two parts, explores the Jakarta Taglibs Project (part of the not-for-profit Apache Software Foundation), which provides a wide array of open-source custom tag libraries for use in JavaServer Pages. First, a brief review of the concept of custom tag libraries is offered, followed by an overview of the workings of the Jakarta Taglibs Project and its various custom tag libraries, and concluding with the open-source development experiences of several members of the Jakarta community."
"Part II of the series explores several recently released Jakarta taglibs, as well as one that is currently in development, and offers sample code that uses these new tag libraries. This installment assumes a general familiarity with the concepts and syntax of JSP custom tag libraries. For a review of these concepts, see Part I of the series (link below)."
"This component also contains the DigestUtils class, which is useful for creating SHA and MD5 digest. The next section shows how to use these classes in real world examples."
"You may wonder why you need Commons Collections at all when the Java Collections Framework is available in the JDK. Well, Collections extends and enhances the Java Collections Framework's classes and interfaces. In fact, I strongly feel that it also should be part of JDK itself."
"The code uses the Commons Chain and Command pattern in the processing layer. For each command-line network command, it has a class to do the processing. These classes are connected to form a chain. When a command is invoked, the first command in the chain is given the arguments. The control flows through the chain until the desired command is identified to do the processing. The goal is to use Commons CLI to parse the arguments and populate the context object, so that the processing classes in the chain can use it."
"I have been developing with Eclipse since its early days, and have found that it is one of the best things that ever happened to me for my Java development. Coming from a background of Java programming on Linux® using nothing but vi and a JDK, Java programming and debugging was a tedious task. Now, thanks to Eclipse, I can throw together quick Java-based prototypes easily. My next thought was why not integrate my JSP development into my Eclipse environment as well? Then I would be able to work more easily with my Java code and JSPs. The goal of this article is to save JSP developers time setting up Eclipse to work with Tomcat."
"I began with the rather voluminous Apache Jakarta Tomcat 5 Servlet/JSP Container documentation with particular emphasis on the Application Developer's Guide. Unfortunately, after several hours with this document, I erroneously concluded that in order to deploy web applications in Tomcat, I would also need to learn how to use Apache Ant. I downloaded, installed, and tested Apache Ant."
