Step Through java.* Classes With JDB

Question

Here is a simple program:
public final class HelloWorld {
  private HelloWorld() {
  public static void main(String[] args) {
    System.out.println("Hello, World!");
}I compile it with the -g option, and run it in jdb:
javac -g HelloWorld.java
jdb HelloWorld
I set a breakpoint in the main function...now I'm wondering why I can't step through the String constructor (or whatever magic happens behind the String literal syntax) and the println method calls. When I use step, it just skips over them! I find that I can set breakpoints in library methods, and use list to see the source, but as soon as I step it flies out of the library method and back to mine. Does anybody know what gives? Is it because the libraries aren't compiled with the -g option???

Answer 1

Thanks for your quick input. It seems you're right about the libraries. I made a dummy class compiled with the -g:none option, added some more lines in the first class (compiled with -g), and ran it through jdb. It stepped over the methods from the class with no debug info...same way as before.
This is annoying. Sun should really provide debug versions of their libraries.
So how does JBuilder let you step through library methods? Did they take the Sun source and recompile it? Do they have a magic debugger?