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What's the difference between java class (.class) and .jar ? Can I say .jar may contains serveral java classes ?<br />
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If there are serveral .class inside a .jar, how can I know which class to run first when I run the jar file ?<br />
<br />
Thx
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What's the difference between java class (.class) and .jar ? Can I say .jar may contains serveral java classes ?

If there are serveral .class inside a .jar, how can I know which class to run first when I run the jar file ?

Thx

Java class and jar

Java is a platform-independent, object-oriented programming language and run-time environment, designed to have as few implementation dependencies as possible such that developers can write one set of code across all platforms using libraries. Most devices will not run Java natively, and require a run-time component to be installed in order to execute a Java program.

Java

Java Enterprise Edition (Java EE) is a specification defining a collection of Java-based server and client technologies and how they interoperate. Java EE specifies server and client architectures and uses profiles to define technology sets targeted at specific classes of applications. All Java EE profiles share a set of common features, such as naming and resource injection, packaging rules and security requirements.