public MultipartUrlConfig() 
{
        this(null);
}

 public MultipartUrlConfig(String boundary) 
{
        args = new Arguments();
        files = new HTTPFileArgs();
        this.boundary = boundary;
}

 public  void addArgument(String name,
    String value) 
{
        Arguments myArgs = this.getArguments();
        myArgs.addArgument(new HTTPArgument(name, value));
}

 public  void addArgument(String name,
    String value,
    String metadata) 
{
        Arguments myArgs = this.getArguments();
        myArgs.addArgument(new HTTPArgument(name, value, metadata));
}

 public Arguments getArguments() 
{
        return args;
}

 public String getBoundary() 
{
        return boundary;
}

 public HTTPFileArgs getHTTPFileArgs() 
{
        return files;
}

 public  void parseArguments(String queryString) 
{
        String[] parts = JOrphanUtils.split(queryString, "--" + getBoundary()); //$NON-NLS-1$
        for (int i = 0; i <  parts.length; i++) {
            String contentDisposition = getHeaderValue("Content-disposition", parts[i]); //$NON-NLS-1$
            String contentType = getHeaderValue("Content-type", parts[i]); //$NON-NLS-1$
            // Check if it is form data
            if (contentDisposition != null && contentDisposition.indexOf("form-data")  > -1) { //$NON-NLS-1$
                // Get the form field name
                final String namePrefix = "name=\""; //$NON-NLS-1$
                int index = contentDisposition.indexOf(namePrefix) + namePrefix.length();
                String name = contentDisposition.substring(index, contentDisposition.indexOf("\"", index)); //$NON-NLS-1$
                // Check if it is a file being uploaded
                final String filenamePrefix = "filename=\""; //$NON-NLS-1$
                if (contentDisposition.indexOf(filenamePrefix)  > -1) {
                    // Get the filename
                    index = contentDisposition.indexOf(filenamePrefix) + filenamePrefix.length();
                    String path = contentDisposition.substring(index, contentDisposition.indexOf("\"", index)); //$NON-NLS-1$
                    if(path != null && path.length()  > 0) {
                        // Set the values retrieved for the file upload
                        files.addHTTPFileArg(path, name, contentType);
                    }
                }
                else {
                    // Find the first empty line of the multipart, it signals end of headers for multipart
                    int indexEmptyLfCrLfLinePos = parts[i].indexOf("\n\r\n"); //$NON-NLS-1$
                    int indexEmptyLfLfLinePos = parts[i].indexOf("\n\n"); //$NON-NLS-1$
                    String value = null;
                    if(indexEmptyLfCrLfLinePos  > -1) {
                        value = parts[i].substring(indexEmptyLfCrLfLinePos).trim();
                    }
                    else if(indexEmptyLfLfLinePos  > -1) {
                        value = parts[i].substring(indexEmptyLfLfLinePos).trim();
                    }
                    this.addNonEncodedArgument(name, value);
                }
            }
        }
}

This method allows a proxy server to send over the raw text from a browser's output stream to be parsed and stored correctly into the UrlConfig object.