JSON to COBOL

It turns out it is fairly simple to transform JSON strings to COBOL using LegStar and Jackson.

To do this you would start from a COBOL fragment and use the usual LegStar COBOL to XSD translator and then generate transformers using LegStar COBOL Binding Generator.

Here is a sample JUnit code performing transformation from JSON to COBOL and vice versa:

package json.lsfileae.test;

import java.io.StringWriter;

import org.codehaus.jackson.map.AnnotationIntrospector;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.xc.JaxbAnnotationIntrospector;

import com.legstar.coxb.host.HostData;
import com.legstar.test.coxb.lsfileae.Dfhcommarea;
import com.legstar.test.coxb.lsfileae.bind.DfhcommareaTransformers;

import junit.framework.TestCase;

/**
* Unit test JSON/COBOL transformation.
*/
public class JacksonTest
extends TestCase {

 /** Hex EBCDIC data orignating from mainframe. */
 public static final String HOST_DATA =
     /*0 0 0 1 0 0 */
     "f0f0f0f1f0f0"
     /*  S .  D .   B O R M A N                  */
     + "e24b40c44b40c2d6d9d4c1d54040404040404040"
     /*  L A B A S   S T R E E T                 */
     + "e2e4d9d9c5e86b40c5d5c7d3c1d5c44040404040"
     /*  3 2 1 5 6 7 7 8 */
     + "f3f2f1f5f6f7f7f8"
     /*  2 6   1 1   8 1  */
     + "f2f640f1f140f8f1"
     /*  $ 0 1 0 0 . 1 1  */
     + "5bf0f1f0f04bf1f1"
     /*  * * * * * * * * *  */
     + "5c5c5c5c5c5c5c5c5c"
 ;

 /** JSON serialization of the host data. */
 public static final String JSON_DATA =
   "{\"comNumber\":100," +
   "\"comPersonal\":{\"comName\":\"S. D. BORMAN\"," +
   "\"comAddress\":\"SURREY, ENGLAND\"," +
   "\"comPhone\":\"32156778\"}," +
   "\"comDate\":\"26 11 81\"," +
   "\"comAmount\":\"$0100.11\"," +
   "\"comComment\":\"*********\"}";

 /** Jackson mapper. */
 private ObjectMapper _mapper;

 /** LegStar transformer. */
 private DfhcommareaTransformers _transformer;

 public void setUp() {
   _mapper = new ObjectMapper();
   AnnotationIntrospector introspector = new JaxbAnnotationIntrospector();
   _mapper.getDeserializationConfig().setAnnotationIntrospector(introspector);
   _mapper.getSerializationConfig().setAnnotationIntrospector(introspector);
   _transformer = new DfhcommareaTransformers();
 }

 /**
  * Transform host data to JSON and check
  * @throws Exception if transformation fails
  */
 public void testHostToJson() throws Exception {
   StringWriter sw = new StringWriter();
   _mapper.writeValue( sw, _transformer.toJava(HostData.toByteArray(HOST_DATA)));
   assertEquals(JSON_DATA,  sw.toString());
 }

 /**
  * Transform JSON to host data and check
  * @throws Exception if transformation fails
  */
 public void testJsonToHost() throws Exception {
   Dfhcommarea dfhcommarea = _mapper.readValue(JSON_DATA, Dfhcommarea.class);
   byte[] hostData = _transformer.toHost(dfhcommarea);
   assertEquals(HOST_DATA, HostData.toHexString(hostData));
 }
}