Android中 SOCKET发送HTTP请求例证

Android中 SOCKET发送HTTP请求例子
目的：客户端用socket连接web服务器发送ｈｔｔｐ请求，访问一个Servlet /service .并接收servlet的相应数据。
我客户端代码可以访问到servlet可是servlet用request.getPrameter("data") 取不到请求内容.
请指点：代码如下

public class Client {        public static void main(String[] arg) {            Socket socket;            try {                socket = new Socket("10.20.64.203", 7001);                OutputStream os = socket.getOutputStream();                InputStream ins = socket.getInputStream();                String data= getXmlString();                StringBuffer sb = new StringBuffer();                sb.append("POST /service HTTP/1.1\r\n");// 注意\r\n为回车换行                sb.append("Accept-Language: zh-cn\r\n");                sb.append("Connection: Keep-Alive\r\n");                sb.append("Host:localhost\r\n");                sb.append("Content-Length:11\r\n");                sb.append("\r\n");                sb.append("data=abc\r\n");                sb.append("\r\n");                      // 接收Web服务器返回HTTP响应包                os.write(sb.toString().getBytes());                os.flush();                byte[] b = new byte[1000];                ins.read(b); //读取http头                InputStreamReader ireader = new InputStreamReader(ins);                java.io.BufferedReader reader = new java.io.BufferedReader(ireader);                String s =  reader.readLine(); //读取内容                System.out.println("response:"+s);                System.out.println(reader.readLine());                System.out.println(reader.readLine());                System.out.println(reader.readLine());                System.out.println(reader.readLine());                System.out.println(reader.readLine());                System.out.println(reader.readLine());                            } catch (UnknownHostException e) {                e.printStackTrace();            } catch (IOException e) {                e.printStackTrace();            }        }