Re: Prototyping and Creating integer objects in RPG for callingJavaclasses

[meovino@xxxxxxxxxxxxxxxxx]

Barbara,

Thanks for the reply.  It compiles fine, but now something strange is
happening.

My RPG program has two parms

D file_in         S            255
D format          S             10I 0

And I'm trying to call it from the command line with the following command:

CALL PGM(ICR001) PARM('/JavaUtil/ImageConversion/in' 13)

In calling it from the command line, I am getting garbage in file_in,
because I'm not padding it out to 255 characters with blanks.  If I clean
it up by looking for the first blank and substringing out everything before
that and putting the result back in file_in, I get exception
"java.lang.NoSuchMethodError:" when calling method "<init>" with signature
(Ljava.io.file;I)V" in class "conversionTest".  If I comment out the
cleanup stuff, it runs, but it obviously does not find the correct
directory.

If I define file_in as

D file_in         S            255A   Varying

I get a "Length of varying length variable is out of range" error.  If I
look at the dump, it tells me that file_in  is 257 characters long.

Mike E.





                    Barbara Morris
                    <bmorris@ca.ibm.c       To:     rpg400-l@midrange.com
                    om>                     cc:
                    Sent by:                Subject:     Re: Prototyping and 
Creating integer objects in RPG for
                    rpg400-l-admin@mi        callingJavaclasses
                    drange.com


                    11/22/02 10:26 AM
                    Please respond to
                    rpg400-l






meovino=/SPx079MrvAgMxX8nMqP6gC/G2K4zDHf@public.gmane.org wrote:
>
> I have re-read the chapter several times, and it looks as if I need to
call
> the Java method passing an instance parameter as the first parm.
> Unfortunately, the book does not appear to give any examples of calling a
> non-static method that does not return a value.  The method is defined as
> follows:
>
> public class conversionTest
> {
>
>   public conversionTest(File f, int format)
>

Ok, I get it now.  A method whose name is the same as the class name is
called a "constructor".  It returns an object of the class.  In RPG, you
prototype it with the special method name *CONSTRUCTOR, and define it to
return an object.  (But you don't have to code the CLASS keyword for the
return value.)

D Class1          C                   'conversionTest'
 *  conversionTest constructor
 *  Java:  public conversionTest(File f, int format);
D newConversionTest...
D                 PR              O   ExtProc(*JAVA:
D                                            Class1:*CONSTRUCTOR)
 *  method parameters
D  f                              O   Class(*JAVA:'java.io.File')
D                                     Const
D  format                       10I 0 Value

D obj             S               O   Class(*JAVA:Class1)

c        eval   obj = newConversionTest (fFile : format)

It's a good idea to put the Java version of the method header as a
comment in the RPG.

Sorry if I was a bit snarky before.  As well as reading about RPG and
Java, I think it's important for you to read a bit about Java.  Sun has
a nice tutorial here:
http://java.sun.com/docs/books/tutorial/java/index.html.


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