same classname, different package

[Claire Yang]

I wrote two programs with the same classname and saved them in different directories:
(1)current-directory/p1-->A.java

package p1;
public class A {
public void amethod() {
System.out.println("p1.A");
}
public static void main(String[] args) {
A a=new A();
a.amethod();
}
}

(2)current-directory/p2-->A.java

package p2;
public class A {
public void amethod() {
System.out.println("p2.A");
}
public static void main(String[] args) {
A a=new A();
a.amethod();
}
}

My question is that how to use the 2 classes in the program "P.java"?
current-directory-->P.java

import p1.*;
import p2.*;
class P {
public static void main(String[] args) {
p1.A a1=new p1.A();
a1.amethod();
p2.A a2=new p2.A();
a2.amethod();
}
}

I tried many ways and I got the error messages like: "cannot resolve symbol" or "reference to A is ambiguous" or "p1.A is already defined in a single-type import". What did I miss? Please help, thanks a lot.

[Graeme Brown]

Your code, package and directory structure are fine. My guess is you do not have the current directory in your CLASSPATH. Try adding it then recompile.

[mei l.h.]

I agree with Brown

[Ilja Preuss]

If you use fully qualified classnames (which you have to), you don't need the import statements. Try removing them.
Did that help?

[Claire Yang]

Thanks for all your replies.
I set "classpath=.", remove the first two import lines in P.java.

class P {
public static void main(String[] args) {
p1.A a1=new p1.A();
a1.amethod();
}
}

And I STILL got the following error messages:

P.java:3: cannot resolve symbol
symbol  : class A
location: class p1
                p1.A a1=new p1.A();
                  ^
P.java:3: cannot resolve symbol
symbol  : class A
location: class p1
                p1.A a1=new p1.A();
                              ^
2 errors

I tried to use javac -classpath" and got the same error messages.
Why? I thought I understood what the package is and how to use it, but now I'm confused!
[ November 13, 2002: Message edited by: Claire Yang ]

[Ron Newman]

What directory is the file "A.class" in?
It should be in the "p1" subdirectory of the directory that contains "P.java".

[Rene Liebmann]

Maybe it is wrong, but you need to write the CLASSPATH in upper case letters. So please set in your environment the CLASSPATH=.;
If you do this, then you don't need javac -classpath, you simply need javac.

[Claire Yang]

Thanks, Ron & Rene.
I changed "classpath=." to "CLASSPATH=." and got the same error messages.
The structure of all the files and classes is drawn as the following:

current-dir
    |-- P.java
    |-- P.class
    |-- p1(dir)
    |   |-- A.java
    |   |-- A.class
    |-- p2(dir)
        |-- A.java
        |-- A.class

What's wrong with the programs?
[ November 14, 2002: Message edited by: Claire Yang ]

[Ron Newman]

Nothing is wrong with it. The files are exactly where they should be, and the program runs fine on my system.

[Claire Yang]

Ron, thanks a lot for testing my programs. I finally found the "suspect" that caused all these problems. For testing the programs, I wrote another file "p1.java" with classname P1: ( p1.java is in the same directory of P.java)

import p1.*;
class P1 {
public static void main(String[] args) {
A a=new A();
System.out.print("In class P1: ");
a.amethod();
}
}

"p1.java" can run completely but cause "P.java" compile error. If I changed "p1.java" to "P1.java", then each program runs fine. Since "p" & "P" are not the same to java, how come "p1.java" will affect "P.java"? Could you explain that to me? Or I still miss something? But I'm sure for one thing: not to use the ambiguous filename & classname to test programs!
[ November 14, 2002: Message edited by: Claire Yang ]

[Ron Newman]

The class and the file MUST have exactly the same name, including the same capitalization.

[Claire Yang]

But I didn't declare the class with public.

[Ron Newman]

That makes no difference. The class name and file name must match in spelling and capitalization, always. The same goes for package names and directory names.

[Claire Yang]

I understand now, thanks a lot, Ron.

[fred rosenberger]

Palak Agarwal,
Your post was moved to a new topic.