java socket,该怎么处理

java socket
今天尝试java socket ,碰到了问题，服务器端和客户端可以连通，服务器端收到客户端链接后，给客户端发送一个信息，但是客户端不知道为什么收到这个信息，貌似开在readline那里了。
有人能帮忙看看吗：
客户端

Java code

import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.net.Socket;import java.net.SocketException;import java.net.UnknownHostException;public class mainJava {    //static String ip = "127.0.0.1";//    static int port = 8888;     /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        try {            Socket sc= new Socket ("127.0.0.1",8888);            if(sc!=null)            {                sc.setKeepAlive(true);                OutputStreamWriter os = new OutputStreamWriter(sc.getOutputStream());                 BufferedWriter bw = new BufferedWriter(os); //将字节流包装为字符流（根据大家需求而定）                 bw.write("发送一个请求给服务器"); //写入请求信息                 BufferedReader br = getReader(sc);                //sc.                String tmpstr = "";                boolean isFinish = false;                while(isFinish==false)                {                    tmpstr=br.readLine();                                        if(tmpstr!=null)                    {                        if(tmpstr=="end")                        {                            isFinish = true;                        }else                        {                            System.out.println(tmpstr);                        }                    }else                    {                                            }                    System.out.println("收到消息");                }            }                                } catch (UnknownHostException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }  catch(SocketException e)        {            System.out.println("连接失败");            //e.printStackTrace();            e.getCause();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    private static BufferedReader getReader(Socket socket) throws IOException {          InputStream in = socket.getInputStream();          return new BufferedReader(new InputStreamReader(in));      }  }

Java code

import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.IOException;import java.io.OutputStreamWriter;import java.net.ServerSocket;import java.net.Socket;public class testSocket {    /**     * @param args     */    static int port = 8888;    public static void main(String[] args) {        // TODO Auto-generated method stub         try {            ServerSocket listensocket = new ServerSocket(port);            Socket tmp = null;            int counter = 1;            boolean flag = true;            System.out.println("-------->Server");            while(flag)            {                tmp = listensocket.accept();                OutputStreamWriter os = new OutputStreamWriter(tmp.getOutputStream());                 BufferedWriter bw = new BufferedWriter(os);                 bw.write("发送给客户端一个相应");                 bw.flush();                //BufferedReader br = getReader(sc);                counter++;                if(counter == 10)                {                    flag = false;                }            }        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }       }}

socket的outputstream是向服务器发送信息，
socket的inputstream是读取服务器返回的信息，
你的getreader方法中取的就是inputstream
[解决办法]

Java code

 bw.write("发送给客户端一个相应"); bw.writr("\n");
[解决办法]
1. 我用了bw.close()也可以，为什么readline在接收一次之后，就开始返回null
bw.close() 意味着都关闭流了，readLine当然啥都读不到了。。。