gcj and '-Wall'?

Sat Apr 1 00:00:00 GMT 2000

It seems that '-Wall' is not supported with gcj.
Is this correct? I was hoping to use gcj to let me
know about any unused variables, and any other possible
bugs..
For that matter, does anyone know any other java compiler which has -Wall
like feature? 
bash$ cat hello.c 
#include<stdio.h>
main () {
 char ch;
 printf("hello\n");
}
bash$ gcc -Wall hello.c 
hello.c:2: warning: return-type defaults to `int'
hello.c: In function `main':
hello.c:3: warning: unused variable `ch'
hello.c:5: warning: control reaches end of non-void function
bash$ cat HelloWorld.java 
public class HelloWorld {
 public static void main(String [] args) {
 char ch;
 System.out.println("Hello");
 }
}
bash$ gcj -Wall --main=HelloWorld HelloWorld.java 
bash$