How to handle uploaded file data (multipart) at the Camunda App in any Listener class?

I am uploading a document with some other parameters in the process task.
Now I need to handle all the parameters and the uploaded document in the Listener class.
How to handle the multipart (uploaded document) in the listener class ?
Is there any builtin class available for this ?

I want to upload file on the alfresco using the camunda. I receive all the parameters separately and the uploaded file data as a stream in the execute method of the JavaDelegate implementor class. But I do not get the metadata for the uploaded file. I want complete detail for the uploaded file. How can I get the metadata for the file? We can achieve the same using the Multipart in the servlet class. I want to achieve the same in the listener class associated with the task form.

I found the solution.
Instead of JavaDelegate class, I used the TaskListener interface.
Here is the code.

public class DocumentDataTaskListener implements TaskListener{
private final static Logger LOGGER = Logger.getLogger(“DOC-DATA-LISTENER”);

public void notify(DelegateTask delegateTask) {
	try {
		LOGGER.log(java.util.logging.Level.INFO, "Called method notify()");
	    FileValue fileValue  = (FileValue) delegateTask.getVariableTyped("documentFile");
               String fileName = fileValue.getFilename(), 
               InputStream fileData = fileValue.getValue(), 
               String mimeType = fileValue.getMimeType()

catch(Exception e) {
LOGGER.log(java.util.logging.Level.INFO, "Error while uploading file data. Reason: "+e.getMessage());