急求socket编程阻塞问题

我想做个测试，用cs模式，从客户端传一个对象给服务器，服务器修改这个对象的属性，再传回客户端。但是出了个问题。客户端运行到ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());这一行时，停住了。
服务器端也是运行到ObjectInputStream ois= new ObjectInputStream(socket.getInputStream());这一行停住了。
请大侠解释一下，为什么。

 public class Client {

    public static void main(String[] args) {
         Good good = new Good();
         User user = new User();
         good.setName("good one");
         good.setPrice(18);

         user.setAge(21);
         user.setName("jack");
                try {
                    Socket socket =new Socket("192.168.52.129",30000);
                    System.out.println("socket successful");
                    ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());
                    ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
                    System.out.println("oos is ok");

                    oos.writeObject(good);
                    socket.shutdownOutput();
                    ois.readObject();
                    System.out.println(good.getName()+good.getPrice());


                    oos.close();
                    ois.close();
                    socket.close();
                } catch (UnknownHostException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (ClassNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }


    }
}

 public class Server {

    public static void main(String[] args) throws Exception {

        try {
            ServerSocket serverSocket = new ServerSocket(30000);
            System.out.println("服务器已经启动，等待连接");
            Socket socket = serverSocket.accept();
            System.out.println("服务器收到请求");
            ObjectInputStream ois= new ObjectInputStream(socket.getInputStream());
            System.out.println("ois is ok");
            ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
            System.out.println("oos is ok");
            Good good = (Good)ois.readObject();
            System.out.println(good.getName()+good.getPrice());
            good.setName("servergood");
            good.setPrice(25);
            socket.shutdownInput();
            oos.writeObject(good);
                    ois.close();
                    oos.close();
                    socket.close();

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        }
    }

用线程解决Socket的getInputStream阻塞

两边都block在read上了吧，结果谁都没有发数据出去。

自己修改代码后发现，创建了ois之后，不能马上创建oos。这样就会阻塞，oos什么时候用，什么时候再创建。