Reading COBOL datastructures from Java

paweloque picture paweloque · Apr 29, 2009 · Viewed 22.5k times · Source

Is there a way to read COBOL data in a Java program? More concretely I'm confronted with the following case:

I have a file with fixed length records of data. The data definition is done as COBOL copybooks. I think of a library which is taking into account the copybooks and would be able to read those records.

Ideally, it should be possible to generate basic Java classes and structures based on the copybook information. In a later step the datarecords would be parsed and the data filled into objects of those generated classes.

Do you know a library providing this kind of functionality? Or any other techniques to cope with the problem of reading COBOL data?


There are some commercial tools which provide this functionality. They are, however, very expensive. Do you know any open-source alternative or a combination of different tools to provide the entire functionality? For example the cb2xml reads copybook structures and transforms them into XML. A later step would be to generate a record reader based on the cb2xml XML information. Or to use a record reader which is configurable. Do you know a COBOL record reader (decoder)?

Answer

Bruce Martin picture Bruce Martin · May 4, 2009

You could look at JRecord or cb2java. Both allow you to access COBOL files, but neither will generate the full classes.


Update Jan 2011

Since the original answer:

  • JRecord continues be developed. There is now a JRecord Code generator available as either a standalone program or in the Recordeditor. This Code Generator will build JRecord JRecord code from a COBOL Copybook. See RecordEditor Jrecord CodeGen)
  • Development on cb2java has stopped
  • cobol2j has been written. There have been no updates for a year.
  • There is also Legstar again nothing published for a few years

Update Aug 2017

The RecordEditor has a Generate option for generating Java / JRecord code from a COBOL Copybook. See RecordEditor Code Generation notes for details.

Update Jan 2018

There is some information on generating Java~JRecord code in this question / answer:

How do you generate java~jrecord code for a Cobol copybook