Apache Overview HOWTO: Java projects

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## 15. Java projects

For historical reasons, Java projects can be found both under the java.apache.org and jakarta.apache.org umbrellas. The final goal is that over time all Java projects will move under the Jakarta umbrella.

The goal of the Jakarta Project is to provide commercial-quality server solutions based on the Java Platform that are developed in an open and cooperative fashion.

The Java on Apache community is a very dynamic and active one, as shown by the quantity and quality of its subprojects, which are described now.

## 15.1 Ant

You can think of Ant as the Java equivalent of make. It is a big success with Java related projects. Developers can write Java instead of shell commands. This means increased portability and extensibility. Instead of Makefiles Ant has XML files. You can learn more about ANT here.

Related talk

- F19: Using Ant to build Java code

## 15.2 ORO and Regexp

ORO is a complete package that provides regular experession support for Java. It includes Perl5 regular expression support, glob expressions, etc. All under the Apache license. You can learn more about ORO here. You can find another lightweight regular expression package, Regexp.

## 15.3 Slide

Slide is a high-level content management framework. Conceptually, it provides a hierarchical organization of binary content which can be stored into arbitrary, heterogenous, distributed data stores. In addition, Slide integrates security, locking and versioning services.

If you are familiar with WedDAV, Slide uses it extensively. In simple words, what Slides provides is an unified, simple way to access resources and information. These resources can be stored in a database, the filesystem, etc. and accessed either thru a WebDAV interface or Slide's own API.

You can learn more at the Slide home page.

## 15.4 Struts

Struts is an Apache project that tries to bring the Model-View-Controller (MVC) design paradigm to web development. It builds on Servlet and JavaServer Pages technologies. The model part is made up of Java server objects, which represent the internal state of the application. Enterprise Java Beans are commonly used here. The view part is constructed via JavaServer Pages (JSP), which is a combination of static HTML/XML and Java. JSPs also allow the developer to define new tags. The controller part consists of servlets, which take requests (GET/POST) from the client, perform actions on the model and update the view by providing the appropriate JSP. You can learn more at the Struts project pages.

## 15.5 Taglibs

The JavaServer pages technology allows developers to provide functionality by adding custom tags. The Taglibs project intends to be a common repository for these extensions. It includes tags for common utilities (i.e. date), SQL database access, etc.

You can learn about TagLibs here. More documentation is included in the package.

## 15.6 Tomcat

Tomcat is the flagship product of the Jakarta project. It is the official reference implementation for the Java Servlet 2.2 and JavaServer Pages 1.1 technologies.

You can learn more in the Tomcat homepage. The Tomcat project was started with a code donation from Sun Microsystems.

## 15.7 Velocity

Velocity is a Java based template engine. It can be used as a stand-alone utility for generating source code, HTML, reports, or it can be combined with other systems to provide template services. Velocity has a Model View Controller paradigm that enforces separation of Java code and the HTML template.

You can learn more about Velocity here. Velocity is part of other projects like Turbine

## 15.8 Watchdog

The Watchdog project provides the validation tests for the Servlet and JavaServer Pages specifications. You can find more information here

## 15.9 JServ

Apache JServ is in a maintenance only mode at this point. This means that there will be no new official releases and that only well tested patches are being committed. No new features are being added. If you are looking for the latest implementation of a Java Servlet Engine and/or Java Server Pages (JSP) then you should consider using the Jakarta Tomcat product available from the Jakarta Project.

## 15.10 JSSI

JSSI is an implementation of server side included in the Java language. Server side includes are tags includes in files that get processed before the page is served to the client (for example to include the current date) You can find more information here.

## 15.11 Apache JMeter

The Apache JMeter is a 100% pure Java desktop application designed to load test functional behavior and measure performance. It was originally designed for testing Web Applications but has since expanded to other test functions.

It can be used to test static and dynamic resources and get inmediate visual feedback.

You can see some screenshots and learn more here.

## 15.12 Server Pages Foundation Classes

SPFC is a set of libraries to help solve common problems in server side application development. They focus on two of them:

- Mixing HTML and Java: Provides a library of classes that takes care of the HTML generation and that can be integrated with the rest of the Java code.
- HTTP is a stateless protocol: SPFC provides session support, so applications can keep track of users as they navigate the website. The application developer does not need to worry about the specific details of page generation. He can think in more general traditional application terms. You can learn more about SPFC here

## 15.13 Element Construction Set

Element Construction Set (ECS) is a JAVA API for generating elements for various markup languages. It directly supports HTML 4.0 and XML, but can easily be extended to create tags for any markup language.

It allows the generation of mark up tags using Java function calls, leading to a much cleaner solution than mixing HTML and Java code. You can learn more at the ECS project page.

## 15.14 Avalon

If you are familiar with Perl or BSD systems, Avalon is roughly the equivalent of CPAN or the Ports collection for Java Apache technologies. It does not only provide guidelines for a common repository of code, it goes one step further: is an effort to create, design, develop and maintain a common framework for server applications written using the Java language. It provides the means so server side Java projects can be easily integrated and build on each other.

## 15.15 JAMES (Java Apache Mail Enterprise Server)

Complementary to the other Apache server side technologies, JAMES provides a 100% pure Java server designed to be a complete and portable enterprise mail engine solution based on currently available open protocols (SMTP, POP3, IMAP, HTTP)

More information can be found here.

## 15.16 PicoServer

A lightweight HTTP/1.0 server in pure Java. The project seems to be stalled and no code is available. The website and CVS are no longer available.

## 15.17 Jetspeed

Jetspeed is a web based portal written in Java. It has a modular API that allows aggregation of different data sources (XML, SMTP, iCalendar)

Related talk:

- TH11: Writing an enterprise information portal with JetSpeed

## 15.18 Turbine

Turbine is a servlet based framework that allows experienced Java developers to quickly build secure web applications. Turbine brings together a platform for running Java code and reusable components, everything under the Apache license. Some of its features include:

- Integration with template systems
- MVC style development
- Access Control Lists
- Localization support
- etc.

If you are interested, you can visit the Turbine web site.

## 15.19 Jyve

The Jyve project is built on top of the Turbine framework. It is an application that provides a web based FAQ system

## 15.20 Alexandria

Alexandria is an integrated documentation management system. It brings together technologies common to many open source projects like CVS and JavaDoc. The goal is to integrate source code and documentation to encourage code documentation and sharing. More information here

Related talk

- W06: An introduction to Alexandria

## 15.21 Log4j

This package provides a logging framework that Java applications can use. It can be enabled at runtime without modifying the binary and has been designed with performance in mind. It can be found here

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