从android到PC的TCP无法使用java工作 [英] TCP from android to PC not working using java

问题描述

我正在尝试通过 TCP 从我的 android 手机(使用 java 应用程序)向我的计算机发送一条简单的消息.我有一个正在我的计算机上侦听的套接字，但是一旦我运行这个应用程序，它就会崩溃.我对 Android 开发真的很陌生，所以请耐心等待...

I am trying to send a simple message over TCP from my android phone (using java application) to my computer. I have an socket that is listening on my computer but as soon as I run this app, it crashes. I am really new to Android developing so please bear with me...

这是我的 Java 代码:

package com.scorekeep.clienttcp;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

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


public class MainActivity extends Activity {

    EditText textOut;


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

        Socket socket = null;
        try {
            socket = new Socket("10.0.0.10",5000);
            DataOutputStream DOS = new DataOutputStream(socket.getOutputStream());
            DOS.writeUTF("HELLO_WORLD");
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

推荐答案

根据要求提供扩展示例:

As requested an extended example :

import android.app.*;
import android.os.*;
import android.util.*;
import java.io.*;
import java.net.*;

public class MainActivity extends Activity 
{
    @Override
     protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        new connection().execute();
    }
}

 class connection extends AsyncTask<String,String,String> {
public static PrintWriter out;
BufferedReader in;
public static boolean running = true;
    @Override
    protected String doInBackground(String... message) {

        try
        {
            InetAddress serverAddr = InetAddress.getByName("localhost");
            Socket socket = new Socket(serverAddr, 8008);
            // send the message to the server
            out = new PrintWriter(new BufferedWriter(
                              new OutputStreamWriter(socket.getOutputStream())), true);

            in = new BufferedReader(new InputStreamReader(
                                    socket.getInputStream()));

        while(running) {
            String msgfromserver = in.readLine();
        }
        }
        catch (Exception e)
        {}

        return null;
    }

    public static void sendmsg(String msg){
        if(out!=null){
            out.println(msg);
            out.flush();
        }
    }
}

用法:从按钮的 OnClick 方法调用 connection.sendmsg("some text");

Usage: Call connection.sendmsg("some text"); from OnClick method of button

并设置 connection.running = false; onbackpress.(或活动结束前)

And set connection.running = false; onbackpress. (Or before finishing activity)

这篇关于从android到PC的TCP无法使用java工作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！