Special Edition Using Java 2 Standard Edition

Using JAR Files

Java introduced Java Archive files (JAR files) back in JDK 1.1. JAR files bundle multiple files into a single deployable archive file that can be used in Java applications and/or applets. JAR files provide many valuable features for Java applications. Some of the features are

• Bundling

• Compression

• Portability

• Versioning

• Security

• Decreased Download Time

Each of these features is described in more detail in the following sections.

Bundling

A complex applet or application might consist of dozens or hundreds of Java classes, each stored in a separate class file (recall that each public class must be stored in a separate file). For applets, the Web browser makes an HTTP connection to load each file, as needed, from the server. Establishing ...