SoftwareMining COBOL-to-Java Converter: Code Comparison

SoftwareMining's automated, rule-based Translation Toolkit converts COBOL applications into maintainable Java. This page compares a small COBOL program with the Java source code generated by the SoftwareMining converter.

The example demonstrates how COBOL business logic, data definitions and program flow are represented in readable, object-oriented Java code. Functional behaviour must ultimately be validated against the original COBOL application.

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This introductory example focuses on readability and structural clarity. It does not demonstrate more advanced conversion requirements such as GO TO handling, dead-code analysis, REDEFINES, CICS integration or pointer translation.

Case Study: ING Bank mainframe modernization case study

For detailed coverage of these capabilities, see the Enterprise COBOL Translator Feature List .

COBOL-to-Java Conversion Features

01-level COBOL declarations are converted into Data Access Objects (DAO) capable of handling REDEFINES, COMPUTATIONAL, OCCURS-DEPENDING, and other COBOL data features (see the WS-DATA structure).
01-level declarations in the FILE SECTION are translated into Object Relational Model (ORM) classes.
01-level WORKING-STORAGE definitions used in CICS READ / WRITE statements are also converted into ORM classes.
Unreferenced 01-level declarations are automatically commented out to keep the generated code clean.
The translator removes references to unused DAOs and reuses shared structures where possible.
Many GO TO statements are removed automatically; remaining ones are supported through the SoftwareMining Framework libraries.
Batch programs: The translated Java code can be executed from the command line or through Unix Shell scripts translated from JCL.
Online applications: The translated Java system can be deployed on Java application servers such as Apache Tomcat, Jakarta EE servers, or Spring-based environments.

See: Runtime Performance Comparisons

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COBOL to Java: Side-by-Side Code Comparison

  PROGRAM-ID. LOAN.
  DATA DIVISION.
  FILE SECTION.

  WORKING-STORAGE SECTION.
  01  WS-DATA.
    05 PRINCIPAL          PIC 9(9) VALUE 0.
    05 INTEREST-RATE      PIC 99V99 VALUE 0.
    05 LOAN-LENGTH        PIC 99 VALUE 0.
    05 NEXT-INTEREST      PIC 99V99.
    05 NEXT-YEAR          PIC 99.
  01 CLIENT-RECORD.
    05 NAME               PIC X(20).
    05 ADDRESS            PIC X(20) OCCURS 3 TIMES.
    05 ID                 PIC 9(4) COMP.

  ...

// Sample COBOL to Java translated code

public class Loan extends BaseService  {
  
// Notes: 01 level WS-DATA name is simplified (Optional)
// and converted to a DAO
// The DAO handles REDEFINES, COMP, OCCURS-DEPENDING, ...
  
  private WsData data = new WsData(this);
  
// Client-RECORD has been translated to ClientRecord DAO,
// but since the program does not reference ClientRecord,
// it will automatically be commented out.
  
  
// private ClientRecord clientRecord = new ClientRecord(this);
  
  ...

  * Main entry point to program
   LOAN-MAIN-001.

  *  -
  * CLEAR SCREEN AND READ DATA
  *  -

       IF LOAN-LENGTH > 4 THEN
          COMPUTE START-YEAR = LOAN-LENGTH - 4
       ELSE
          COMPUTE START-YEAR = 0.

       IF INTEREST-RATE > 0.4 THEN
          COMPUTE START-INTEREST = INTEREST-RATE - 0.4
       ELSE
          COMPUTE START-INTEREST = 0
       END-IF

       MOVE 1 TO YEAR-ROW.

  *  -
  * GO THRU THE NUMBER OF YEARS
  *  -

       MOVE "% Rate->" TO DSP-NO-YRS(1).
       MOVE START-YEAR TO NEXT-YEAR
       PERFORM VARYING YEAR-ROW FROM 2 BY 1 UNTIL YEAR-ROW = 11
         PERFORM DO-NEXT-ROW
         ADD 1 TO NEXT-YEAR
       END-PERFORM.

  *  -
  *  AND EXIT
  *  -
       STOP RUN.

/**
 * Main entrance to program
 */
protected void loanMain () {
  //  -
  // CLEAR SCREEN AND READ DATA
  //  -
  if (data.getLoanLength() > 4) {
    data.setStartYear(data.getLoanLength() - 4);
  } else {
    data.setStartYear(0);
  }
  if (data.getInterestRate() > 0.4) {
    data.setStartInterest(data.getInterestRate() - 0.4);
  } else {
    data.setStartInterest(0.0);
  }
  data.setYearRow(1);

  //  -
  // GO THRU THE NUMBER OF YEARS
  //  -
  displayResult.setNoYrs(0, "% Rate->");
  data.setNextYear(data.getStartYear());
  // initialize loop variable
  data.setYearRow(2);
  while (data.getYearRow() != 11) {
    doNextRow();
    data.setNextYear(data.getNextYear() + 1);
    data.setYearRow(data.getYearRow() + 1);
  }

  //  -
  // AND EXIT
  //  -
  stop();
}

  *
  * Calculates values for individual rows
  *
   DO-NEXT-ROW.

       MOVE START-INTEREST TO NEXT-INTEREST

       PERFORM VARYING INTEREST-COL FROM 1 BY 1
         UNTIL INTEREST-COL = 10
         MOVE NEXT-INTEREST TO DSP-RESULT(1, INTEREST-COL)
         PERFORM CALCULATE
         MOVE NEXT-RESULT TO DSP-RESULT(YEAR-ROW, INTEREST-COL)
         ADD 0.1 TO NEXT-INTEREST
       END-PERFORM.

/**
 * Calculates values for individual rows
 */
protected void doNextRow () {
  data.setNextInterest(data.getStartInterest());

  data.setInterestCol(1);
  while (data.getInterestCol() != 10) {
    displayResult.setResult(
      0,
      data.getInterestCol() - 1,
      data.getNextInterest()
    );
    calculate();
    displayResult.setResult(
      data.getYearRow() - 1,
      data.getInterestCol() - 1,
      data.getNextResult()
    );
    data.setNextInterest(data.getNextInterest() + 0.1);
    data.setInterestCol(data.getInterestCol() + 1);
  }
}

  *
  * The next paragraph calculates CELL values
  *
   CALCULATE.
       COMPUTE INTDEC = NEXT-INTEREST / (12.0 * 100.0)
       COMPUTE NUMMONTHS = NEXT-YEAR * 12.0
       ...

/**
 * The next paragraph calculates CELL values
 */
protected void calculate () {
  data.setIntdec(data.getNextInterest() / (12.0 * 100.0));
  data.setNummonths((double) data.getNextYear() * 12.0);
  ...
}