Read packed decimal and convert to numeric in spring boot

All,

I am using a Spring boot application to store data in DB. I am getting this data from IBM MQ through Kafka topic. I am getting messages in EBCDIC format, so used cobol copybook, JRecord, cb2xml jars to convert to readable format and store in DB.

Now i am getting another file also in the same manner, but after conversion the data looks like this:

10020REFUNDONE
10021REFUNDTWO ·"   ÷/
10022REFUNDTHREE   oú^  " 
10023REFUNDFOUR              ¨jÄ ò≈

Here is how i am converting to readable format from ebcdic:

AbstractLineReader reader = null;
StringBuffer finalBuffer = new StringBuffer();
        try {
            String copybook = "/ds_header.cbl";
            reader = CustomCobolProvider.getInstance().getLineReader(copybook, Convert.FMT_MAINFRAME, new BufferedInputStream(new ByteArrayInputStream(salesData)));
AbstractLine line;
        while ((line = reader.read()) != null) {
            if (null != line.getFieldValue(REC_TYPE)){
                finalBuffer.append(line.getFullLine());
            }
        }
            }
        

and this is my getLineReader method:

public AbstractLineReader getLineReader(String copybook, int numericType, InputStream fileStream) throws Exception {

        String font = "";
        if (numericType == 1) {
            font = "cp037";
        }

        InputStream stream = CustomCobolProvider.class.getResourceAsStream(copybook);

        if(stream == null ) throw new RuntimeException("Can't Load the Copybook Metadata file from Resource....");
        LayoutDetail copyBook = ((ExternalRecord)this.copybookInt.loadCopyBook(stream, copybook, CopybookLoader.SPLIT_REDEFINE, 0, font, CommonBits.getDefaultCobolTextFormat(), Convert.FMT_MAINFRAME, 0, (AbsSSLogger)null).setFileStructure(Constants.IO_FIXED_LENGTH)).asLayoutDetail();
        AbstractLineReader ret = LineIOProvider.getInstance().getLineReader(copyBook, (LineProvider)null);
        ret.open(fileStream, copyBook);
        return ret;
    }

I am stuck here with the numeric conversion, i got to know it is coming in packed decimal. I have nil knowledge on cobol and mainframe, referred few sites and got to know how to convert from ebcdic to readable format. Please help!

The problem is getFullLine() method does not do any field translation; you need to access individual fields. You can use the line.getFieldIterator(0) to get a field iterator for the line.

Also unless you are using an ancient version of JRecord, you are better off using the JRecordInterface1 class.

Some thing like the following should work:

    StringBuffer finalBuffer = new StringBuffer();

    try {
        ICobolIOBuilder iob = JRecordInterface1.COBOL .newIOBuilder(copybookName)
                               .setFont("cp037") 
                               .setFileOrganization(Constants.IO_FIXED_LENGTH)
                                   ;  


        AbstractLineReader reader = iob.newReader(dataFile);
        while ((line = reader.read()) != null) {
            String sep = "";
            for (AbstractFieldValue fv : line.getFieldIterator(0)) {
                finalBuffer.append(sep).append(fv);
                sep = "\t";
            }
            finalBuffer.append("\n");
        }

        reader.close();
    } catch (Exception e) {
       // what ever ....
    }

Other points

With MQ data source you do not need to create line-readers. You can create lines directly from a byte array:

        ICobolIOBuilder iob = JRecordInterface1.COBOL .newIOBuilder(copybookName)
                               .setFont("cp037") 
                               .setFileOrganization(Constants.IO_FIXED_LENGTH)
                                   ;  

        AbstractLine line = iob.newLine(byteArrayFromMq);
        for (AbstractFieldValue fv : line.getFieldIterator(0)) {
            // what ever
        }