I am trying to update the values by passing the account id

but i am getting the ERROR has RESPONSE CODE 400.

CAN ANY ONE HELP ME WHAT WENT WRONG IN MY CODE.

package com.JSON.Response;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Collection;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.PostMethod;
import org.json.JSONArray;
import org.json.JSONObject;
import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.methods.*;
import org.apache.commons.httpclient.params.HttpMethodParams;
import org.apache.http.impl.client.DefaultHttpClient;


public class EndPointQuery {
    


    private static final Collection newname = null;

    private static JSONObject oauthLogin(String loginUri, String clientId, String clientSecret, String username, String password) {
          //  HttpRequest req = new HttpRequest(); u
        
        return null;
        }
        
    private static JSONArray posturlconnection(String loginUri, String clientId, String clientSecret, String username, String password) {
        try {
            String strUrl = loginUri + "/services/oauth2/token", strInstanceURL = "", strAccessToken = "";
            String strURLParameter = "grant_type=password&client_id=" + clientId + "&client_secret=" + clientSecret + "&username=" +
            URLEncoder.encode(username, "UTF-8") + "&password=" + URLEncoder.encode(password, "UTF-8");
            URL wsURL = new URL(strUrl);
            HttpURLConnection wsCon = (HttpURLConnection) wsURL.openConnection();
            wsCon.setRequestMethod("POST");
            wsCon.setDoInput(true);
            wsCon.setDoOutput(true);
            wsCon.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            //wsCon.setRequestProperty("Content-Type", "application/json");
            wsCon.setRequestProperty("Contect-Length", "" + Integer.toString(strURLParameter.getBytes().length));
            wsCon.setRequestProperty("charset", "utf-8");
            OutputStreamWriter writer = new OutputStreamWriter(wsCon.getOutputStream());
            writer.write(strURLParameter);
            writer.flush();
            writer.close();
            String line = "";
            BufferedReader reader = new BufferedReader(new InputStreamReader(wsCon.getInputStream()));
            while ((line = reader.readLine()) != null)
            {
                JSONObject jsnObj = new JSONObject(line);
                strInstanceURL = jsnObj.getString("instance_url");
                strAccessToken = jsnObj.getString("access_token");
                
            }
            JSONArray jsnArray = null;
                        
            String accountId="0019000000SvJkt";
            PostMethod patch = new PostMethod(strInstanceURL + "/services/data/v20.0/sobjiects/Account/" + accountId + "?_HttpMethod=PATCH");
            HttpURLConnection wsConQry = (HttpURLConnection) wsURL.openConnection();
            System.out.println("Open Connection@@@@@@@@@@@@@@@@@@@"+wsConQry);
            wsConQry.setRequestMethod("POST");
            wsConQry.setRequestProperty("Authorization", "OAuth " + strAccessToken);
            System.out.println("ResponseCode"+wsConQry.getResponseCode());
            if(wsConQry.getResponseCode() == HttpURLConnection.HTTP_OK)
                
            {
                
                jsnArray = new JSONArray(line);
                JSONObject update1=new JSONObject();
                update1.put("Name", newname);
                System.out.println("Updatename");
                HttpClient httpclient = new HttpClient();
                httpclient.executeMethod(patch);
                
                /*BufferedReader readerRes = new BufferedReader(new InputStreamReader(wsConQry.getInputStream()));
                while ((line = readerRes.readLine()) != null) {
                    jsnArray = new JSONArray(line);
                    JSONObject update1=new JSONObject();
                    update1.put("Name", newname);
                    System.out.println("Updatename");
                    HttpClient httpclient = new HttpClient();
                    httpclient.executeMethod(patch);
                }*/
                System.out.println(jsnArray.toString());
                return jsnArray;
                
                
                                        
            }
            /*System.out.println(jsnArray.toString());
            return jsnArray;*/
            
        } catch(Exception ex) {
            System.out.println(ex.getMessage());
        }
        return null;
    }
    
        public static String restTest(String name) {
                      posturlconnection("https://login.salesforce.com", "3MVG9Y6d_Btp4xp4O7MWPf5592ThVeMSzmSMxLE.c8Efg.._MSWi1TIkCuwgg0n6INTp8C",
                        "4455896129340", "username","Password");
           
                return null;
        }


}
REGARDS

sailer