Basic capabilities

• Compile .java or .class to .o
• Compile .java to .class
• Compile .jar to .so
• C++ native interface
• Generate C++ headers from .class

  $ gcj -C hi.java
  $ gcjh hi
  $ cat hi.h
  // DO NOT EDIT THIS FILE - it is machine generated -*- c++ -*-
  
  #ifndef __hi__
  #define __hi__
  
  #pragma interface
  
  #include <java/lang/Object.h>
  #include <gcj/array.h>
  
  extern "Java"
  {
    class hi;
  }
  
  class hi : public ::java::lang::Object
  {
  public:
    static void main (JArray< ::java::lang::String *> *);
    hi ();
  
    static ::java::lang::Class class$;
  };
  
  #endif /* __hi__ */
  

• Simple example:

  $ cat hi.java
  public class hi
  {
    public static void main (String[] args)
    {
      System.out.println ("hi");
    }
  }
  $ gcj --main=hi -o hi hi.java
  $ ./hi
  hi
  $ ls -l hi
  -rwxr-xr-x    1 tromey   users       13056 Feb 18 19:47 hi*
  

• Eclipse screen shot from Mark Wielaard