Monday, February 18, 2013

Jersey Mutipart - Resource that Produces MULTIPART Response and Client code to process it



Handling 'MULTIPART/MIXED'  using Jersery Apis.

Jars required:

a. ) jersey-bundle-1.13.jar
b. ) jersey-multipart-1.13.jar

Jersey Client to GET a Multipart Http Request

______________________________________--

Lets build a client equired to GET a Multipart Response. This Response that has two BodyParts.

1. An xml Input : This is the first body part. It is an Xml representation for a JAXB object  ,MyEntity E
2. Byte[] array : This array of bytes is the second body part. This byte array is the content of the file produced by a REST resource

So the aim is to create a jersery client and GET a MULTIPART request.


                  final long resourceId = 1026l;
final String exportUrl =  "get Export Resource URL"
final String path = "/" + resourceId ;

Client c = Client.create();
WebResource service = c.resource(exportUrl );

MultiPart multipart = service.path(path).type(MediaType.APPLICATION_XML).header( headerKey, headerValue).get(MultiPart.class);

List bodyParts = multipart.getBodyParts();
String xmlResponse = bodyParts.get(0).getEntityAs(String.class);
byte[] exportedContent = bodyParts.get(1).getEntityAs(byte[].class);
System.out.println("XML  = " + xmlResponse);
System.out.println("\n\n");
System.out.println("ExportedContent : \n");
System.out.println(new String(exportedContent ));


/////////////// The FileExport Resource that would Produce this Multipart Request ///////////////////////

       @GET
@Path("{id}")
@Produces("multipart/mixed")
public Response read(@PathParam("id") String resourceId , @Context HttpHeaders headers,
@Context UriInfo uriInfo) // add other @Context arguments if required
{
          // process Request and fetch Xml Response Strinrg
           String responseStr = getResponseStrForResourceId( reesource Id );
         
           // build Multipart Web Response
           MultiPart multipart = buildMultipartResponse(responseStr);
 
            Response response = Response.status(status).header( headerKey, headerValue ) .entity(multipart).type(MultiPartMediaTypes.MULTIPART_MIXED).build();

return response;

       }

  // build Multipart Data
   MultiPart buildMultipartResponse(String xmlResponseStr)
{
MultiPart multiPart = new MultiPart();
multiPart.bodyPart(new BodyPart(xmlResponseStr, MediaType.APPLICATION_XML_TYPE)).bodyPart(
new BodyPart(getAttachmentBytes(), MediaType.APPLICATION_OCTET_STREAM_TYPE));

return multiPart;
}

Jersey Mutipart - Resource that Consumes MULTIPART and Client that POSTs such a request


Handling 'MULTIPART/MIXED'  using Jersery Apis.

Jars required:

a. ) jersey-bundle-1.13.jar
b. ) jersey-multipart-1.13.jar

Jersey Client to POST Multipart Http Request

______________________________________--

Lets build a client that requires to POST to a REST resource a multipart request that has two body parts

1. An xml Input : This is the first body part. Let the JAXB object created for this be Represented by MyEntity E
2. Byte[] array : This array of bytes is the second body part. This byte array is the content of the file that needs to imported , along with the above xml input

So the aim is to create a jersery client and post a multipart request.

        String fileImporUrl = "URl to the resource that would handle this request"

   Client c = Client.create();
   WebResource service = c.resource(fileImporUrl );

   // Construct a MultiPart with two body parts

    // Construct the JAXB object for the Input Xml 
   MyEntity E = new MyEntity ();
          // E.setname( "anbc" );
          //E.setId(123 );
          .............
         ..... Build the Entity
 
            // read the file and get bytes to import
   byte[] bytesToImport = getBytesToImport();
 
               // Construct Multipart Request. Content-type of the first part is 'application/xml '
              // and second part is 'appication/octet-stream'
   MultiPart multiPart = new MultiPart().
    bodyPart(new BodyPart(E, MediaType.APPLICATION_XML_TYPE)).
     bodyPart(new BodyPart(bytesToImport, MediaType.APPLICATION_OCTET_STREAM_TYPE));

   // POST the request
   ClientResponse response = service.path("/import").
     type("multipart/mixed").header( headerKey, headerValue).post(ClientResponse.class, multiPart);

   System.out.println( "Import Response status = " + response.getStatus() );


/////////////// A FileImport Resource that would consume this Multipart Request ///////////////////////

    @POST
@Consumes("multipart/mixed")
@Produces({ MediaType.APPLICATION_XML, MediaType.TEXT_XML })
public Response importFile(MultiPart multipart, @Context HttpHeaders headers, @Context UriInfo uriInfo) // add other context if required
{

final int INDEX_XML = 0; final int INDEX_FILE_CONTENT = 1; MultipartBodyEntityContent bodyEntityContent = new MultipartBodyEntityContent(); MyEntity E = null; BodyPartEntity fileContentAsBodyPart = null; try { E = multipart.getBodyParts().get(INDEX_XML).getEntityAs(MyEntity.class); fileContentAsBodyPart = (BodyPartEntity) multipart.getBodyParts().get(INDEX_FILE_CONTENT).getEntity(); byte[] byteContent = getByteArrayFromInputStream( fileContentAsBodyPart .getInputStream() );

// Process the MyEntity E and byteContent and return Response }

}

// get byte[] from Input Stream byte[] getByteArrayFromInputStream(InputStream in) { ByteArrayOutputStream buffer = new ByteArrayOutputStream(); int nRead; byte[] data = new byte[4096]; while ((nRead = in.read(data, 0, data.length)) != -1) buffer.write(data, 0, nRead); buffer.flush(); buffer.close(); return buffer.toByteArray(); }