communicate with xml-rpc

[tah_206207]

hello everyone i want to communicate with xml-rpc in my code but i can't! and get error when i compile my code.
my code

package com.thr.FireEagle;
import java.net.MalformedURLException;
import org.apache.xmlrpc.XmlRpcException;
import org.apache.xmlrpc.client.XmlRpcClientConfigImpl;
import java.net.URL;
import org.apache.xmlrpc.client.XmlRpcClient;
//import java.util.Vector;

public class JavaClient {
	private static Object[] params;
	   public JavaClient( )
	   {
	      params = new Object[] { "http://dl4.mihandownload.com/2011/Alipour0c/2011.4/Welcome_MAC_World_Mihandownload.com.rar" };
	   }
	       public static void main( String[] args )
	       {
	          System.out.println( "execute" );
	          XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();
	          try {
	            config.setServerURL(new URL("http://127.0.0.1:6800/rpc"));
	         } catch (MalformedURLException e) {
	            // TODO Auto-generated catch block
	            e.printStackTrace();
	         }
	          XmlRpcClient client = new XmlRpcClient();
	          client.setConfig(config);
	                   
	          try {
	            client.execute("aria2.addUri", params );
	         } catch (XmlRpcException e1) {
	            // TODO Auto-generated catch block
	            e1.printStackTrace();
	         }
	         

	    }

}

i get this error when i compile my code!

execute
org.apache.xmlrpc.XmlRpcException: URI is not provided.
	at org.apache.xmlrpc.client.XmlRpcStreamTransport.readResponse(XmlRpcStreamTransport.java:197)
	at org.apache.xmlrpc.client.XmlRpcStreamTransport.sendRequest(XmlRpcStreamTransport.java:156)
	at org.apache.xmlrpc.client.XmlRpcHttpTransport.sendRequest(XmlRpcHttpTransport.java:143)
	at org.apache.xmlrpc.client.XmlRpcSunHttpTransport.sendRequest(XmlRpcSunHttpTransport.java:69)
	at org.apache.xmlrpc.client.XmlRpcClientWorker.execute(XmlRpcClientWorker.java:56)
	at org.apache.xmlrpc.client.XmlRpcClient.execute(XmlRpcClient.java:167)
	at org.apache.xmlrpc.client.XmlRpcClient.execute(XmlRpcClient.java:137)
	at org.apache.xmlrpc.client.XmlRpcClient.execute(XmlRpcClient.java:126)
	at com.thr.FireEagle.JavaClient.main(JavaClient.java:29)

error occurred at line:

client.execute("aria2.addUri", params );

but i don't no how to fix it!
unfortunately aria2 has the method aria2.addUri but i surprised what in code i can't communicate with aria2!
please help me to fix this problem.

[tah_206207]

No everyone can help me?

[tah_206207]

If i want to create gui for aria2c you encourage me to use xml-rpc or JSON-RPC? which is better in java programming language? i can't communicate with xml-rpc in my code!
please help me to choose best approach.
tnx