Why does a public class with another public subclass in the same code itself errs?

[Deepa Marupaka]

public class PublicTest{
public static void main(String args[]){
}
}
public class SubTest extends PublicTest{
}

This gives the following error when compiled:
javac PublicTest.java
PublicTest.java:5: class SubTest is coderanch, should be declared in a file named SubTest.java
public class SubTest extends PublicTest{
^
1 error
Can anyone please explain...

[huiying li]

Java source file can only have, at most, one public class, it must have the same name as the file name.
Either change one of the class to package access or put it in a separate file, the code should be fine.

[Yoo-Jin Lee]

Deepa,
You cannot have two top-level classes that are both declared public- only a max of one is allowed in a file.
If you remove the public access modifier from SubTest it'll compile.
cheers,
Yoo-Jin.

[Yoo-Jin Lee]

Huiying,
I guess you beat me to the punch.
Yoo-Jin.

[Deepa Marupaka]

Thanks Huiying and Yoo-jin!