Jar packages and dynamic link libraries

1 jar package closer to dynamic link library

Java at compile time, although the import of other jar package, but it does not copy the other jar in the source code into its own class file, it just uses the name in the jar package.

At the time of execution, both your own and dependent jar packages are loaded into the JVM, and the link is completed before execution, which is more like a dynamic-link library.

2 JVM Find jar Package

Various class loader go to the specified directory to find the jar package.

Bootstrap class loader go to Jre/lib directory,

Extention class loader go to Jre/lib/ext directory,

Application class loader to classpath the specified directory. Manually specify the classpath at the time of execution,

Java-classpath [Some path to the jar, for Example-classpath C:\\java\\myclasses.jar] MyProgram

3 classpath in Eclipse, which is the use of third-party libraries

Jar packages and dynamic link libraries