Socket ObjectOutpuStream ObjectInputStream

Question

我正在编写简单的客户端-服务器应用程序。一切正常，但是当我将InputStream和OutputStream更改为ObjectOutputStream和ObjectInputStream时，我的应用程序不会发送消息。有人能帮我指出问题所在吗？

下面是Serwer.java：

class InWorke implements Runnable{

    BufferedReader odczyt=null;
    String slowo;
    ObjectInputStream ois=null;
    Message message;

    InWorke(ObjectInputStream ois) {
        this.ois=ois;
    }

    public void run() {
        while(true) {
            try {
                slowo = (String) ois.readObject();
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            System.out.println(slowo);
            Thread.yield();
        }               }

}

class OutWorke implements Runnable{
    Socket socket=null;
    BufferedReader odczytWe=null;
    DataOutputStream zapis=null;
    String slowo=null;
    Message message; // it is the simple class to serialization
    ObjectOutputStream oos;

    OutWorke(Socket socket,ObjectOutputStream oos) {
        this.socket=socket;
        this.oos=oos;
    }

    public void run() {
        while(true) {
            odczytWe=new BufferedReader(new InputStreamReader(System.in));
            try {
                slowo=odczytWe.readLine();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            try {
                    oos.writeObject(slowo);
                    oos.flush();
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            Thread.yield();

    }

}
}

public class Klient {
    public static void main(String[] args) {

    Socket socket=null;
    ExecutorService exec=Executors.newCachedThreadPool();

    ObjectOutputStream oos=null;
    ObjectInputStream ois=null;

    try {
        socket=new Socket("localhost", 8881);
    } catch (UnknownHostException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    try {
        //we=socket.getInputStream();
        ois=new ObjectInputStream(socket.getInputStream());
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    try {
        //wy=socket.getOutputStream();
        oos=new ObjectOutputStream(socket.getOutputStream());
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    exec.execute(new OutWorke(socket, oos));
    exec.execute(new InWorke(ois));

 }
} 

Klient.java：

class InWorker implements Runnable{

    Socket socket=null;
    //InputStream we=null;
    //OutputStream wy=null;
    String slowo=null;
    BufferedReader odczyt=null;
    ObjectOutputStream oos;
    ObjectInputStream ois;
    Message message=null;

    InWorker(Socket socket,ObjectInputStream ois) {
        this.socket=socket;
        this.ois=ois;
    }

    public void run() {
                while(true) {
                try {
                    slowo=(String) ois.readObject();
                } catch (ClassNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                System.out.println(slowo);
                Thread.yield();
            }

            }
}

class OutWorker implements Runnable{

    DataOutputStream zapis=null;
    BufferedReader odczyt=null;
    //OutputStream wy=null;
    String tekst=null;
    ObjectOutputStream oos=null;
    Message message;

    OutWorker(ObjectOutputStream oos) {
        this.oos=oos;
    }

    public void run() {
        while(true) {
        odczyt=new BufferedReader(new InputStreamReader(System.in));
        try {
            tekst=odczyt.readLine();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        try {
            oos.writeObject(tekst);
            oos.flush();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        Thread.yield();
        }
    }

}

public class Serwer {

    public static void main(String[] args) {
        ServerSocket serversocket=null;
        Socket socket=null;
        //InputStream we=null;
        //OutputStream wy=null;
        ObjectOutputStream oos=null;
        ObjectInputStream ois=null;

        ExecutorService exec=Executors.newCachedThreadPool();

        try {
            serversocket=new ServerSocket(8881);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            socket=serversocket.accept();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            ois=new ObjectInputStream(socket.getInputStream());
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            oos=new ObjectOutputStream(socket.getOutputStream());
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        exec.execute(new InWorker(socket, ois));
        exec.execute(new OutWorker(oos));

    }

}

Answer 1

检查ObjectInputStream的构造函数：constructor。

上面写着：

此构造函数将一直阻塞，直到相应的ObjectOutputStream写入并刷新了标头。

因此，您需要创建并刷新相应的ObjectOutputStream。现在，您正在为服务器和客户端在输出流之前创建ObjectInputStreams。它们会阻止程序，因为没有创建输出流。您应该首先创建输出流，对其调用flush，然后才能创建输入流。

Answer 2

正如Nikita所指出的，问题的根源就在于此。实现解决方案是让服务器和客户端以相反的顺序获取输入和输出流。如果一个先获取输入流，让另一个先获取输出流，依此类推。我切换了客户端，让它先获取输出流，一切都正常了。然后我把它放回去，改变服务器，一切都是这样工作的……您可以选择要更改的项。

参考：http://docs.oracle.com/javase/6/docs/api/index.html?java/io/ObjectOutputStream.html