Wrong Name Error

Question

Hi,
I created a package in eclipse with 3 .java files under it.
In each of the three java files I have included the "package testpackage;" clause at the top.
My first 2 files (lets call them one.java and two.java) is referenced in three.java, thus I use the import statement for both one and two in three.java.
After I compile all 3 successfully in Eclipse, I go to the command line, to the specific directory (testpackage) and run: java one, but I get the message:
NoClassDefFoundError: 1 (wrong name: testpackage/one)
What is wrong?

Answer 1

I found that you need to be in the PACKAGE directory when you execute the "java" command, not the directory containing the .class file(s). For example, if you have the following statement in your java program:
package buServer;
Your .class files (BUreceiver.class in my case) will reside in a directory named buServer. You need to be in the directory ABOVE the one that contains your class files (the package directory) and execute the program as shown below:
java buServer/BUreceiver
The above assumes that the current directory is in your CLASSPATH or is given by the " -cp ." on the java command line.
The basic problem, I think, is that CLASSPATH points to directories that are supposed to contain .class files. When you use a package, you have to give the fully quallified name of the class with a root beginning in one of the directories in the CLASSPATH. In my case, the "package" statement says my class should be in a <CLASSPATH>\buServer\ directory. When I was in the buServer directory (containing my .class files) and added it to the CLASSPATH, there was no <CLASSPATH>\buServer\ directory, since the buServer\ directory was inside CLASSPATH. However, when I tried to execute it without qualifying it with the "buServer", it saw the package statement in the class file that was there and gave me the "wrong name" error.
Another solution would have been to take out the package statement from the program.