.ear, .war, and .jar files are simply files zipped using Java jar tool. Each file is created for a different purpose:
.jar files
Jar (Java Archive) files contain libraries, resources and accessory files such as property files.
.war files
War (Web Archive) files contain web applications that can be deployed on any servlet/jsp container. It also contains other files required by the web application such as html, javascript, css, etc.
.ear files
Ear (Enterprise Archive) files contain EJB modules.
To open an archive file created with JAR such as .jar, .war, ear files, use the following command:
$ jar -xf file.jar $ jar -xf file.war