Java code to import JAR file

Question

I created a JAR file and then added it to my project's build path. Now how do I import it to my class so I can use it? I've only tried import java-class.jar; so far.

Answer 1

You import classes, not jar files, in your Java source code.

Lets assume you have someJar.jar which contains class definitions for 3 classes, FirstClass.class, SecondClass.class and ThirdClass.class, all of which are in package org.somepackage.

Given the above, you would add

import org.somepackage.FirstClass

at the top of a source file to import the class called FirstClass.

Answer 2

To do this, you need to add it to the classpath when compiling and running, like

java -cp myJar.jar a.b.myMainClass

or

javac -cp myJar.jar a/*