How to resolve packaging problem

Question

I have created 2 packages
1) Pack3 2) Pack4
Pack3 contains MyClass1.java and
Pack4 contains MyClass2.java
but in actual java files ,I have given package names as Pack1 and Pack2 respectively......
package pack1;
public class MyClass1{
     public void find(){
          System.out.println("GOT..?");
package pack2;
import pack1.MyClass1;
public class MyClass2{
     public static void main(String args[]){
               MyClass1 m1=new MyClass1();
               m1.find();
               System.out.println("......");
If I COMPILE WHOLE SOURCE AT A TIME then it compiles correctly and create directories pack1 and pack2 and respective classes in those directories but IF I TRIED TO COMPILE ONLY PACK4 DIRECTORY....THEN IT FAILS TO COMPILE......AND GIVES ERROR AS PACK1 DOES NOT EXIST...this is quite obvious..because MyClass2.java refers to MyClass1.java which is in PACK1 and pack1 does not exist on disk.
How to solve this problem...?
I want to compile only single directory at a time...I mean HOW TO COMPILE ONLY PACK2 even though actual package name is different than directory name in which it resides...?and I am not getting why it compiles when I compile whole source at a time.
Thanks,
Archan
Edited by: Archana144 on Apr 25, 2008 7:17 AM

Answer 1

First off, Pack3 and Pack4 are not packages. If they were, they would be included in your package declarations.
When you compile a class, you need to include package roots and .jar files in the classpath such that all the classes you're using can be found. When you compile both classes at the same time, the compiler knows about both of them and can find them. When you only compile one of the classes, you need to tell the compiler where the package root for the other class is.
[Link to Packages Tutorial|http://java.sun.com/docs/books/tutorial/java/package/index.html]