Calling JAVA method from RPGLE

[Bull_A_]

Hi all,

hopefully this should be an easy one to solve! I have just started doing a bit of a refresher on creating JAVA objects and calling their methods from and RPG program. However, I cannot for the life of me remember how all of this stuff worked (or rather does work). I started off with something simple: attempt to retrieve the current time (in milliseconds) from the system.

In JAVA this would simply look like:

long milliSeconds = System.currentTimeMillis();

I have this in my RPG routine:

//=======================================================================*
      // Variable Declarations                                                 *
      //=======================================================================*

       dcl-pr   System object(*JAVA:'java.lang.System')
                       extproc(*JAVA:'java.lang.System':*CONSTRUCTOR);
       end-pr;

       dcl-pr   CurrentTime int(20:0)
                       extproc(*JAVA:'java.lang.System':'currentTimeMillis');
       end-pr;

       dcl-s    systemObject           like(System);
       dcl-s    milliSeconds           like(CurrentTime);

      //=======================================================================*
      // Program Mainline                                                      *
      //=======================================================================*

        systemObject = System();
        milliSeconds = CurrentTime(systemObject);

        *inlr = *ON;
        return;

      //=======================================================================*
      // Subroutines                                                           *
      //=======================================================================*
       begsr *pssr;
         dump;
         return;
       endsr;

      //=======================================================================*

Retrieving the system object to call the method from is working fine, but I am falling short on the call to the method implementation. The error I get is:

Java exception received when calling Java method.

RPG procedure SLAVETEST in program QDEVOPLIB/SLAVETEST received Java exception "java.lang.NoSuchMethodError: java/lang/System.currentTimeMillis()J" when calling method "currentTimeMillis" with signature "()J" in class "java.lang.System".

Now I checked the signature of the method using (JAVAP -S java.lang.System) and this was the result:

public static native long currentTimeMillis();
  descriptor: ()J

I am at a loss as to what I am getting this error, maybe because it is static but I am not sure. Any ideas or comments would be appreciated. Thanks

[JonBoy]

Yep - I think you need to add STATIC to the currentTimeMillis prototype, and that in turn means removing the parm from the call so it should be:

dcl-pr   CurrentTime int(20:0) static                           
         extproc(*JAVA:'java.lang.System':'currentTimeMillis');                                                                 
end-pr;                                                         
systemObject = System();     
milliSeconds = CurrentTime();

Seems to work for me - although I didn't check if the result was accurate.

[jtaylor___]

Make your CurrentTime ptototype static, and delete the System prototype (you don't need it).