从服务器（Java应用程序）到Android应用程序的套接字

Question

我有一个问题，我不知道是否可能。

我有一个作为客户端套接字的Android应用程序。

这是将消息发送到Android App中的服务器的代码：

private class SendMessage extends AsyncTask<Void, Void, Void> {

    @Override
    protected Void doInBackground(Void... params) {
        try {
            System.out.println("envia mensaje");
            client = new Socket("ip of server", 4444); // connect to the server
            printwriter = new PrintWriter(client.getOutputStream(), true);
            printwriter.write(messsage); // write the message to output stream

            printwriter.flush();
            printwriter.close();
            client.close(); // closing the connection

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

}

同时，在Android App中，在4445端口中创建了一个套接字：

private class SocketServerThread extends Thread {

    static final int SocketServerPORT = 4445;
    int count = 0;

    @Override
    public void run() {
        try {
            serverSocket = new ServerSocket(SocketServerPORT);
            SlimpleTextClientActivity.this.runOnUiThread(new Runnable() {

                @Override
                public void run() {
                    System.out.println("I'm waiting here: "
                            + serverSocket.getLocalPort());
                }
            });

            while (true) {
                Socket socket = serverSocket.accept();
                count++;
                message += "#" + count + " from " + socket.getInetAddress()
                        + ":" + socket.getPort() + "\n";

                SlimpleTextClientActivity.this.runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        System.out.println(message);
                    }
                });

                /*SocketServerReplyThread socketServerReplyThread = new SocketServerReplyThread(
                        socket, count);
                socketServerReplyThread.run();*/

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

}

这是服务器代码，它在4444端口中创建一个套接字：

public static void main(String[] args) {
    try {
        serverSocket = new ServerSocket(4444); // Server socket

    } catch (IOException e) {
        System.out.println("Could not listen on port: 4444");
    }

    System.out.println("Server started. Listening to the port 4444");


    while (true) {
        try {



            clientSocket = serverSocket.accept(); // accept the client connection
            inputStreamReader = new InputStreamReader(clientSocket.getInputStream());
            bufferedReader = new BufferedReader(inputStreamReader); // get the client message
            message = bufferedReader.readLine();



            System.out.println("Dirección entrante"+clientSocket.getInetAddress());
            //System.out.println("Dirección entrante2"+clientSocket.get());

            System.out.println(message);


                ip_a = clientSocket.getInetAddress().toString().substring(clientSocket.getInetAddress().toString().indexOf("/")+1, clientSocket.getInetAddress().toString().length());
                        //message.substring(message.indexOf(":")+1, message.length()).trim();
                System.out.println("realiza conexión a ip:#"+ip_a+"#");
                messsage = "enviado desde el servidor"; // get the text message on the text field


                SendMessage(ip_a);




            inputStreamReader.close();
            clientSocket.close();

        } catch (IOException ex) {
            System.out.println("Problem in message reading");
        }
    }

}

这可以正常工作，但我想通过套接字具有的IP将消息从服​​务器发送到Android设备。

我尝试使用clientSocket.getInetAddress（）和clientSocket.getRemoteSocketAddress（），但无法正常工作。 我在4445端口的Android应用程序中创建了一个套接字，但是服务器无法连接到android应用程序的套接字。

你能帮助我吗？

提前致谢

Answer 1

好吧，我会试试的。

这是我的服务器应用程序：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;


public class SimpleTextServer {

private static ServerSocket serverSocket;
private static Socket clientSocket;
private static InputStreamReader inputStreamReader;
private static BufferedReader bufferedReader;
private static String message;
private static Socket client;
private static String messsage;
private static PrintWriter printwriter;
static String ip_a;

public static void main(String[] args) {
    try {
        serverSocket = new ServerSocket(4444); // Server socket

    } catch (IOException e) {
        System.out.println("Could not listen on port: 4444");
    }

    System.out.println("Server started. Listening to the port 4444");
    System.out.println("Server started. Listening to the port 4444:"+getIpAddress());

    while (true) {
        try {



            clientSocket = serverSocket.accept(); // accept the client connection
            inputStreamReader = new InputStreamReader(clientSocket.getInputStream());
            bufferedReader = new BufferedReader(inputStreamReader); // get the client message
            message = bufferedReader.readLine();



            System.out.println("Dirección entrante"+clientSocket.getInetAddress());
            //System.out.println("Dirección entrante2"+clientSocket.get());

            System.out.println(message);


                ip_a = clientSocket.getInetAddress().toString().substring(clientSocket.getInetAddress().toString().indexOf("/")+1, clientSocket.getInetAddress().toString().length());
                        //message.substring(message.indexOf(":")+1, message.length()).trim();
                System.out.println("realiza conexión a ip:#"+ip_a+"#");
                messsage = "enviado desde el servidor"; // get the text message on the text field


                SendMessage(ip_a);




            inputStreamReader.close();
            clientSocket.close();

        } catch (IOException ex) {
            System.out.println("Problem in message reading");
        }
    }

}






public static void SendMessage(String ip) {


        try {
            System.out.println("comienza a enviar mensaje");
            client = new Socket(ip, 4445); // connect to the server
            printwriter = new PrintWriter(client.getOutputStream(), true);
            printwriter.write(messsage); // write the message to output stream

            printwriter.flush();
            printwriter.close();
            client.close(); // closing the connection

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();

    }

}

public static String getIpAddress() {
    String ip = "";
    try {
        Enumeration<NetworkInterface> enumNetworkInterfaces = NetworkInterface
                .getNetworkInterfaces();
        while (enumNetworkInterfaces.hasMoreElements()) {
            NetworkInterface networkInterface = enumNetworkInterfaces
                    .nextElement();
            Enumeration<InetAddress> enumInetAddress = networkInterface
                    .getInetAddresses();
            while (enumInetAddress.hasMoreElements()) {
                InetAddress inetAddress = enumInetAddress.nextElement();

                if (inetAddress.isSiteLocalAddress()) {
                    ip += "SiteLocalAddress: " 
                            + inetAddress.getHostAddress() + "\n";
                }

            }

        }

    } catch (SocketException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        ip += "Something Wrong! " + e.toString() + "\n";
    }

    return ip;
}

}

这是我在Android应用中的活动：

package com.lakj.comspace.simpletextclient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;


public class SlimpleTextClientActivity extends Activity {

private Socket client;
private PrintWriter printwriter;
private EditText textField;
private Button button;
private String messsage;
//ServerSocket serverSocket;

private static ServerSocket serverSocket;
private static Socket clientSocket;

private static InputStreamReader inputStreamReader;
private static BufferedReader bufferedReader;
private static String message;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_slimple_text_client);

    textField = (EditText) findViewById(R.id.editText1); // reference to the text field
    button = (Button) findViewById(R.id.button1); // reference to the send button



    System.out.println("IP DE CLIENTE EMULADOR: "+getIpAddress());
    Thread socketServerThread = new Thread(new SocketServerThread());
    socketServerThread.start();


    //myClientTask.execute();

    // Button press event listener
    button.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            System.out.println("ENVIA MENSAJE BOTON");
            messsage = textField.getText().toString(); // get the text message on the text field
            textField.setText(""); // Reset the text field to blank
            SendMessage sendMessageTask = new SendMessage();
            sendMessageTask.execute();
        }
    });
}

private class SendMessage extends AsyncTask<Void, Void, Void> {

    @Override
    protected Void doInBackground(Void... params) {
        try {
            System.out.println("envia mensaje");
            client = new Socket("ip de servidor", 4444); // connect to the server
            printwriter = new PrintWriter(client.getOutputStream(), true);
            printwriter.write(messsage); // write the message to output stream

            printwriter.flush();
            printwriter.close();
            client.close(); // closing the connection

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.slimple_text_client, menu);
    return true;
}

private class SocketServerThread extends Thread {

    static final int SocketServerPORT = 4445;
    int count = 0;

    @Override
    public void run() {
        try {
            serverSocket = new ServerSocket(SocketServerPORT);
            SlimpleTextClientActivity.this.runOnUiThread(new Runnable() {

                @Override
                public void run() {
                    System.out.println("I'm waiting here: "
                            + serverSocket.getLocalPort());
                }
            });

            while (true) {
                Socket socket = serverSocket.accept();
                count++;
                message += "#" + count + " from " + socket.getInetAddress()
                        + ":" + socket.getPort() + "\n";

                SlimpleTextClientActivity.this.runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        System.out.println(message);
                    }
                });

                /*SocketServerReplyThread socketServerReplyThread = new SocketServerReplyThread(
                        socket, count);
                socketServerReplyThread.run();*/

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

}



@Override
protected void onDestroy() {
    super.onDestroy();

    if (serverSocket != null) {
        try {
            serverSocket.close();

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

private String getIpAddress() {
    String ip = "";
    try {
        Enumeration<NetworkInterface> enumNetworkInterfaces = NetworkInterface
                .getNetworkInterfaces();
        while (enumNetworkInterfaces.hasMoreElements()) {
            NetworkInterface networkInterface = enumNetworkInterfaces
                    .nextElement();
            Enumeration<InetAddress> enumInetAddress = networkInterface
                    .getInetAddresses();
            while (enumInetAddress.hasMoreElements()) {
                InetAddress inetAddress = enumInetAddress.nextElement();

                if (inetAddress.isSiteLocalAddress()) {
                    ip += "SiteLocalAddress: " 
                            + inetAddress.getHostAddress() + "\n";
                }

            }

        }

    } catch (SocketException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        ip += "Something Wrong! " + e.toString() + "\n";
    }

    return ip;
}

}

如果我运行android应用，则消息将发送到服务器，服务器会显示该消息。

但是，服务器无法连接到Android。 IP是无法到达的。 我不知道为什么