Can anyone help me on how I have to run a java application which is in a package, from cmd? Please give me the necessary line that I have to type.

EDIT开发者_开发问答: (Copied a clarifying comment from one of the answers below)

No I mean a normal Java aplication that belongs to a package, like:

package x; class SampleOnly{ }

How you compile (and run) that file.

No i mean a normal java aplication that belongs 2 a package, like package x; class sampleOnly{ } hw u comple dat file

This little "bash session" should explain it:

$ ls .                   # Current directory contains the "x" package
x

$ ls x                   # The "x" package contains a Sample.java file...
Sample.java

$ cat x/Sample.java      # ...which looks like this.
package x;
public class Sample {
    public static void main(String... args) {
        System.out.println("Hello from Sample class");
    }
}

$ javac x/Sample.java    # Use "/" as delimiter and
                         # include the ".java"-suffix when compiling.

$ java x.Sample          # Use "." as delimiter when running, and don't include
                         # the ".class" suffix.
Hello from Sample class

$ 

How to execute an arbitrary jar file, depends on how the jar file in question is pcakaged:

If it's packaged with a manifest containing a Main-class declaraton, you simply do

java -jar program.jar

If it's a regular jar-file you need to know the main class. Let's say it's package.Main:

java -cp program.jar package.Main

(I answered this (indirectly) here: How to convert Java program into jar?) -->

A simple class is written as:

package com.demo.pack;

public class Demo {

public static void main(String[] args) {
    System.out.println("Demo class from package : '"
            + Demo.class.getPackage().getName() + "'");

}

}

This Demo class will be stored under these folders.. Folder sequence will be com/demo/pack. Then the class will be found under pack folder. Now open the command prompt.. I have stored that package in my 'D' drive. Type the following command.

D:>javac com/demo/pack/Demo.java -- press enter

D:>java com.demo.pack.Demo-- press enter..

Done!

By package you mean a .jar file?

java [ options ] <class> [ arguments ... ]
java [ options ] -jar <file.jar> [ arguments ... ]
javaw [ options ] <class> [ arguments ... ]
javaw [ options ] -jar <file.jar> [ arguments ... ]

Running Java applications

If it is a jar that you are talking about then java -jar filename.jar

And not to forget setting the main class and optional classpath in META-INF/MANIFEST.MF

Main-Class: org.example.HelloWorld
Class-Path: greetings.jar

Have a look to the JAR specs at http://java.sun.com/javase/6/docs/technotes/guides/jar/jar.html