安卓客戶端和伺服器端的通訊（勘誤填坑版）

一個很基礎的socket連結示例，僅用作測試和學習使用

首先是伺服器端的程式碼，一個標準的socket server，繫結本地的54321埠

package online.geekgalaxy.test;


import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class SocketServer implements Runnable
{
    public void run()
    {
        try
        {
            //建立ServerSocket
            ServerSocket serverSocket = new ServerSocket(54321);
            while (true)
            {
                //接受客戶端請求
                Socket client = serverSocket.accept();
                System.out.println("accept");
                try
                {
                    //接收客戶端訊息
                    BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
                    String str = in.readLine();
                    System.out.println("read:" + str);
                    //向伺服器傳送訊息
                    PrintWriter out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(client.getOutputStream())),true);
                    out.println("server message");
                    //關閉流
                    out.close();
                    in.close();
                }
                catch (Exception e)
                {
                    System.out.println(e.getMessage());
                    e.printStackTrace();
                }
                finally
                {
                    //關閉
                    client.close();
                    System.out.println("close");
                }
            }
        }
        catch (Exception e)
        {
            System.out.println(e.getMessage());
        }
    }
    //main函式，開啟伺服器
    public static void main(String a[])
    {
        Thread desktopServerThread = new Thread(new SocketServer());
        desktopServerThread.start();
    }
}

附加一個python的服務端

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import socket

s = socket.socket()
host = socket.gethostname()
port = 54321
s.bind((host, port))

s.listen(5)
while True:
    c, addr = s.accept()
    print `Connect from `, addr
    c.send(`Welcome！`)
    c.close()

然後是安卓客戶端，很簡單，但是連線時不能使用127.0.0.1，所以使用了區域網的10段地址

manifest檔案

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="online.geekgalaxy.socketclient">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-sdk android:minSdkVersion="5" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

mainactivity檔案，使用了一種不是特別推薦的方式在新的API基礎上執行socket客戶端命令

package online.geekgalaxy.socketclient;

import android.os.StrictMode;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;

import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements Runnable{

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

    private final String        DEBUG_TAG   = "MainActivity";

    private TextView    mTextView = null;
    private EditText    mEditText = null;
    private Button      mButton = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

        mButton = (Button)findViewById(R.id.Button01);
        mTextView = (TextView)findViewById(R.id.TextView01);
        mEditText = (EditText)findViewById(R.id.EditText01);

        //登陸
        mButton.setOnClickListener(new OnClickListener()
        {
            public void onClick(View v)
            {
                run();
            }
        });
    }


        @Override
        public void run() {
            Socket socket = null;
            String message = mEditText.getText().toString() + "/r/n";
            try {
                //建立Socket
//                  socket = new Socket("192.168.1.110",54321);
                socket = new Socket("10.9.3.132", 54321); //IP：10.14.114.127，埠54321
                //向伺服器傳送訊息
                PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
                out.println(message);

                //接收來自伺服器的訊息
                BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                String msg = br.readLine();

                if (msg != null) {
                    mTextView.setText(msg);
                } else {
                    mTextView.setText("資料錯誤!");
                }
                //關閉流
                out.close();
                br.close();
                //關閉Socket
                socket.close();
            } catch (Exception e) {
                // TODO: handle exception
                Log.e(DEBUG_TAG, e.toString());
            }
        }
}

mainactivity推薦的寫法，使用runnable，是上面程式碼的替代方案

package online.geekgalaxy.socketclient;

//import android.os.StrictMode;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;

import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity{

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

    private final String        DEBUG_TAG   = "MainActivity";

    private TextView    mTextView = null;
    private EditText    mEditText = null;
    private Button      mButton = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

//        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
//        StrictMode.setThreadPolicy(policy);

        mButton = (Button)findViewById(R.id.Button01);
        mTextView = (TextView)findViewById(R.id.TextView01);
        mEditText = (EditText)findViewById(R.id.EditText01);

        //登陸
        mButton.setOnClickListener(new OnClickListener()
        {
            public void onClick(View v)
            {
//                run();
                new Thread(runnable).start();
            }
        });
    }

    Runnable runnable = new Runnable() {
        @Override
        public void run() {
            Socket socket;
            String message = mEditText.getText().toString() + "/r/n";
            try {
                //建立Socket
//                  socket = new Socket("192.168.1.110",54321);
                socket = new Socket("10.9.3.132", 54321); //IP：10.14.114.127，埠54321
                //向伺服器傳送訊息
                PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
                out.println(message);

                //接收來自伺服器的訊息
                BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                String msg = br.readLine();

                if (msg != null) {
                    mTextView.setText(msg);
                } else {
                    mTextView.setText("資料錯誤!");
                }
                //關閉流
                out.close();
                br.close();
                //關閉Socket
                socket.close();
            } catch (Exception e) {
                // TODO: handle exception
                Log.e(DEBUG_TAG, e.toString());
            }
        }
    };
}

然後是layout檔案，裡邊的string被提取了出來，自己補全即可

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <TextView
        android:id="@+id/TextView01"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/servermessage"
        />
    <EditText
        android:id="@+id/EditText01"
        android:text="@string/sendmessage"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">
    </EditText>
    <Button
        android:id="@+id/Button01"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/buttonsend"
        />
</LinearLayout>

build.gradle還是貼出來吧

apply plugin: `com.android.application`

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.2"
    defaultConfig {
        applicationId "online.geekgalaxy.socketclient"
        minSdkVersion 25
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile(`proguard-android.txt`), `proguard-rules.pro`
        }
    }
}

dependencies {
    compile fileTree(dir: `libs`, include: [`*.jar`])
    androidTestCompile(`com.android.support.test.espresso:espresso-core:2.2.2`, {
        exclude group: `com.android.support`, module: `support-annotations`
    })
    compile `com.android.support:appcompat-v7:26.+`
    compile `com.android.support.constraint:constraint-layout:1.0.2`
    testCompile `junit:junit:4.12`
}