Example: Say, you have a class named �Pet� in a project folder �c:\myProject� and package named com.xyz.client, will you be able to compile and run it as it is?
package com.xyz.client;
public class Pet {
public static void main(
String[] args) {
System.out.println("I am found in the classpath");
}
}
To run c:\myProject> java com.xyz.client.Pet
The answer is no and you will get the following exception: �Exception in
thread "main" java.lang.-NoClassDefFoundError: com/xyz/client/Pet�. You need to set the classpath. How can you do that? One of the following ways:
1.Set the operating system CLASSPATH environment variable to have the project folder �c:\myProject�. [Shown in the above diagram as the System �classpath class loader]
2.Set the operating system CLASSPATH environment variable to have a jar file �c:/myProject/client.jar�, which has the Pet.class file in it. [Shown in the above diagram as the System �classpath class loader].
3.Run it with �cp or �classpath option as shown below:
c:\>java �cp c:/myProject com.xyz.client.Pet
OR
c:\>java -classpath c:/myProject/client.jar com.xyz.client.Pet