Question

package pack;


public class sample{ 

 public static void main(String input[])
    {

        NumberFormat numberFormat = new DecimalFormat("#,##0.00##");
    System.out.println(numberFormat.format(44533125.00));

    } 
}

the code is working fine in the current dir.. (c:/myprogram/).

after that i copy the sample.class file and paste it in other dir(d:/myprogram).
i got error while running, like

Exception in thread "main" java.lang.NoClassDefFoundError: sample (wrong name: pack/sample)

In java .class file can run anywhere right? but why i am not able to run?

Answer 1

You should have the class file within the package – so it should be in a directory called pack. Then with the parent directory in the classpath, you’d run

java pack.sample

(You should also change the class name to Sample to follow conventions, btw – and run pack.Sample.)

If you’re building with javac, specify the “-d” option to tell it the base directory, and it will create the appropriate package structure if necessary. For example:

javac -d classes Sample.java

or

javac -d classes src/pack/Sample.java

will (in both cases) create

classes/pack/Sample.class

You could then run

java -cp classes pack.Sample