Configuring a resource to receive multipart/form-data parts from an HTML form submission in JAX-RS 2.0

HTML forms that transmit file data must be configured with the POST method and the multipart/form-data action. This data can be received in one of the two ways by the JAX-RS resource method that accepts it with the IBM Java™ API for RESTful Web Services (JAX-RS) implementation.

About this task

This task provides instructions for configuring a JAX-RS method to use and produce the multipart/form-data parts. The following example illustrates an HTML form:

<form action="http://www.example.com/" method="POST" enctype="multipart/form-data">
    <input type="text" name="fileid" />
    <br />
    <input type="text" name="description" />
    <br />
    <input type="file" name="thefile" />
    <br />
    <input type="submit" name="submit" value="submit"/>
</form>

You can implement the IBM JAX-RS to receive the data in parts, so you can process these parts yourself, if needed.

Procedure

Create a resource method.

You must declare one of the following resource methods to receive and echo multipart/form-data content from an HTTP POST:



@POST
@Consumes("multipart/form-data")
@Produces("multipart/form-data")

public Response postFormData(IMultipartBody multipartBody) {
  List <IAttachment> attachments = multipartBody.getAllAttachments();
         String formElementValue = null; 
         InputStream stream = null;
         for (Iterator<IAttachment> it = attachments.iterator(); it.hasNext();) {
              IAttachment attachment = it.next();
              if (attachment == null) {
                  continue;
              }
              DataHandler dataHandler = attachment.getDataHandler();
              stream = dataHandler.getInputStream();
              MultivaluedMap<String, String> map = attachment.getHeaders();
              String fileName = null;
              String formElementName = null;
              String[] contentDisposition = map.getFirst("Content-Disposition").split(";");
              for (String tempName : contentDisposition) {
                  String[] names = tempName.split("=");
                  formElementName = names[1].trim().replaceAll("\"", "");
                  if ((tempName.trim().startsWith("filename"))) {
                      fileName = formElementName;
                  }
              }
              if (fileName == null) {
                  StringBuffer sb = new StringBuffer();
                  BufferedReader br = new BufferedReader(new InputStreamReader(stream));
                  String line = null;
                  try {
                      while ((line = br.readLine()) != null) {
                          sb.append(line);
                      }
                  } catch (IOException e) {
                      e.printStackTrace();
                  } finally {
                      if (br != null) {
                          try {
                              br.close();
                          } catch (IOException e) {
                              e.printStackTrace();
                          }
                      }
                  }
                  formElementValue = sb.toString();
                  System.out.println(formElementName + ":" + formElementValue);
              } else {
               //handle the file as you want
               File tempFile = new File(fileName);
               ...
              }
         }
         if (stream != null) {
             stream.close();
         }
         return Response.ok("test").build();
}



@POST
@Consumes("multipart/form-data")
@Produces("multipart/form-data")

public Response postFormData(List<IAttachment>attachments) {
  List <IAttachment> attachments = multipartBody.getAllAttachments();
         String formElementValue = null; 
         InputStream stream = null;
         for (Iterator<IAttachment> it = attachments.iterator(); it.hasNext();) {
              IAttachment attachment = it.next();
              if (attachment == null) {
                  continue;
              }
              DataHandler dataHandler = attachment.getDataHandler();
              stream = dataHandler.getInputStream();
              MultivaluedMap<String, String> map = attachment.getHeaders();
              String fileName = null;
              String formElementName = null;
              String[] contentDisposition = map.getFirst("Content-Disposition").split(";");
              for (String tempName : contentDisposition) {
                  String[] names = tempName.split("=");
                  formElementName = names[1].trim().replaceAll("\"", "");
                  if ((tempName.trim().startsWith("filename"))) {
                      fileName = formElementName;
                  }
              }
              if (fileName == null) {
                  StringBuffer sb = new StringBuffer();
                  BufferedReader br = new BufferedReader(new InputStreamReader(stream));
                  String line = null;
                  try {
                      while ((line = br.readLine()) != null) {
                          sb.append(line);
                      }
                  } catch (IOException e) {
                      e.printStackTrace();
                  } finally {
                      if (br != null) {
                          try {
                              br.close();
                          } catch (IOException e) {
                              e.printStackTrace();
                          }
                      }
                  }
                  formElementValue = sb.toString();
                  System.out.println(formElementName + ":" + formElementValue);
              } else {
               //handle the file as you want
               File tempFile = new File(fileName);
               ...
              }
         }
         if (stream != null) {
             stream.close();
         }
         return Response.ok("test").build();
}

The originator of the form POST submission can generate a Content-Transfer-Encoding header for one or more parts of the multipart message. The IBM JAX-RS implementation attempts to auto-decode the payload of the part according to this header when the header is of base64 or quoted-printable encoding type.

Results

You have received and echoed data from an HTTP POST with multipart/form-data Content-Type, by allowing the IBM JAX-RS implementation to split and auto-decode the parts for you, and by receiving the still encoded parts to process yourself.