Chapter 1. Overview


The Apache Jakarta Commons project (http://jakarta.apache.org/commons/) is a collection of reusable Java software components. Each Commons project represents a unit of functionality smaller than a full applicationall of the various Commons projects are intended to help a Java developer build a useful application more quickly by leveraging existing components. Despite the range of functionality included in the various Commons projects, many developers have not taken the time to understand or make use of these libraries, despite their inclusion in many of the most popular open source projects such as Tomcat and Hibernate. On the other hand, considering that the Commons project (as of this writing) consists of twenty-nine released proper components and twenty sandbox components, it's easy to understand why some developers may find the project intimidating. Nonetheless, virtually every development project of any scope can benefit from the introduction of an appropriate Commons package. The Lang package alone contains a broad suite of simple utilities needed by almost every web application, such as a utility function for escaping a bit of HTML or SQL, or a quick class to make it easier to return a Date object formatted to a particular locale.

The difficult thing about the Commons package is not the complexity associated with any particular project, but rather simply remembering what functionality is present. Therefore, the goal of this book is to provide an overview of the most useful Commons package for the broadest array of Java developers. Certain packages solve hard problemsfor example, it's easy to identify a need for the HttpClient package after hitting a wall with the built-in JDK HTTP connectivity suite. Implementing HTTP file upload capability from scratch is somewhat difficult, but the FileUpload package takes care of things nicely. Introspection is great, but BeanUtils is easier. And so on.

Even the small bits add up quicklyit may seem easy to write your own utility methods, but those thirty minute one-offs can start to add up, especially considering the time needed to track down and fix minor bugs. Even more critically, other developers familiar with various Commons packages will immediately know where to find and how to use the utility routines in your project.



    Apache Jakarta Commons(c) Reusable Java Components
    Real World Web Services
    ISBN: N/A
    EAN: 2147483647
    Year: 2006
    Pages: 137
    Authors: Will Iverson

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