Using the Jarray Class

Restriction: This applies to native code only.

The jarray class provides an OO COBOL wrapper for manipulating Java arrays. It is fully documented in the Java Run-time Class Library Reference, which is in docs/ in your COBOL development system installation.

The following COBOL program gets an array from a Java object, finds its dimensions, and displays the contents of the array.

$set ooctrl(+p-f)
 Program-id. ReadArray.
     arraydemo is class "$Java$arraydemo"

 thread-local-storage section.
 01 aJavaObj             object reference.

 01 theTotal        pic 9(9).
 01 CDims           pic x(4) comp-5.
 01 Dims.
   03 Dims-entry    pic x(4) comp-5 occurs 256.
 01 Bounds.
   03 Bounds-entry  pic x(4) comp-5 occurs 256.
 01 ind0            pic x(4) comp-5.
 01 ind1            pic x(4) comp-5.
 01 arrayElement    pic x(4) comp-5.
 01 wsTable         object reference.
 01 wsResult        pic x(4) comp-5.

 procedure division.
   invoke arraydemo "new" returning aJavaObj
   invoke aJavaObj "getArray" returning wsTable

*> find out the number of elements in the array
     invoke wsTable "getDimensions" returning CDims
     display "The array has " CDims " dimension(s)"

*> get the number of elements in each dimension
     display "dimensions are " with no advancing
     invoke wsTable "getBounds" using Bounds
     perform varying ind0 from 1 by 1 until ind0 > CDims
          display Bounds-entry(ind0) with no advancing
          if ind0 < CDims
             display " by " with no advancing
     display " "

*> display each element in the array
     perform varying ind0 from 0 by 1
             until ind0 = Bounds-entry(1)
         move ind0 to Dims-entry(1)
         perform varying ind1 from 0 by 1
                   until ind1 = Bounds-entry(2)
             move ind1 to Dims-entry(2)
             invoke wsTable "getElement" using
                             by value CDims
                             by reference Dims
                             by reference arrayElement
             display "Element " ind0 ","
                   ind1 " is " arrayElement
*> modify the contents of the array
             add 50 to arrayElement
             invoke wsTable "putElement" using
                             by value CDims
                             by reference Dims
                             by reference arrayElement

This is an implementation of the Java arraydemo class used by ReadArray. This program creates a two-dimensional array.

import com.microfocus.cobol.*;

public class arraydemo extends RuntimeSystem
    int myArray[][];
    public arraydemo()
        myArray = new int[5][2];
        int i,j;
        for (i = 0; i < 5; i++)
            for (j = 0; j < 2; j++)
                myArray[i][j] = i * 100 + j;
    public int[][] getArray()
        return myArray;