Web Application Archives

Web Application Archives

If you want to distribute a Web application and run it on another server you package it in a Web application archive (WAR), which is a JAR similar to the package used for Java class libraries, and installed (or deployed) into a Web container. In addition to Web components, a Web application archive usually contains other files including:

• Server-side utility classes (database beans, shopping carts, and so on). Often these classes conform to the JavaBeans component architecture.

• Static Web content (HTML, image, and sound files, and so on).

• Client-side classes (applets and utility classes).

Web components and static Web content files are called Web resources.

A WAR has a specific directory structure. The top-level directory of a WAR is the document root of the application. The document root is where JSP pages, client-side classes and archives, and static Web resources are stored.

The document root contains a subdirectory called WEB-INF, which contains the following files and directories:

• web.xml— the Web application deployment descriptor

• Tag library descriptor files (see Tag Library Descriptors (page 440)).

• classes— a directory that contains server-side classes: servlets, utility classes, and JavaBeans components.

• lib— a directory that contains JAR archives of libraries (tag libraries and any utility libraries called by server-side classes).

You can also create application-specific subdirectories (that is, package directories) in either the document root or the WEB-INF/classes directory.

The ant build files distributed with the tutorial examples construct this directory structure in the build subdirectory.

1 Creating a WAR File

You can manually create a WAR in two ways:

• With the JAR tool distributed with the J2SE SDK. You simply execute the following command in the build directory of a tutorial example:

  
  jar cvf archiveName.war

• With the war task of the ant portable build tool