深入理解Android网络编程——学习笔记（三）——使用TCP实现单客户端通信
1、功能介绍
（1）服务器端
发送消息、接收消息
（2）客户端
发送消息、接收消息
2、文件说明
（1）服务器端
TCP_Server.java 启动服务器相关操作的线程
ServerThread.java 执行线程内的操作（接收、发送消息）
（2）客户端
MainActivity.java 显示、更新客户端界面、启动客户端相关操作线程
ClientThread.java 执行线程内的操作（接收、发送消息）
3、代码说明
3、1、服务器端
（1） TCP_Server.java
public class TCP_Server {
public static void main(String[] args) {
int TCP_SERVER_PORT=12345;
ServerThread serverThread = new ServerThread(TCP_SERVER_PORT);
serverThread.start();
}
}
（2）ServerThread.java
package com.example.chat_tcp;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.InterruptedIOException;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class ServerThread extends Thread {
//创建一个ServerSocket对象
private ServerSocket serverSocket=null;
//mTCP_SERVER_PORT为指定的绑定的端口，为int类型
private int mTCP_SERVER_PORT;
public ServerThread(int TCP_SERVER_PORT){
this.mTCP_SERVER_PORT=TCP_SERVER_PORT;
}
@Override
public void run(){
super.run();
try {
serverSocket = new ServerSocket(mTCP_SERVER_PORT,100);
}catch (IOException e){
e.printStackTrace();
}
try{
while (true) {
System.out.println("Server服务器正在监听");
//监听连接请求
Socket socket = serverSocket.accept();
while (true) {
System.out.println("客户端已连接");
//写入读Buffer中
BufferedReader in = new BufferedReader
(new InputStreamReader(socket.getInputStream())); //获取输入流
//放到写的Buffer中
BufferedWriter out = new BufferedWriter
(new OutputStreamWriter(socket.getOutputStream()));//获取输出流
//读取接收信息，转换为字符串
String incomingMsg = in.readLine() +
System.getProperty("line.separator");
//显示接收信息
System.out.println(incomingMsg);
//生成发送字符串
BufferedReader br=new BufferedReader
(new InputStreamReader(System.in));
String outgoingMsg=null;
System.out.println("please enter you message:");
outgoingMsg=br.readLine();
outgoingMsg+=System.getProperty("line.separator") + "googbye
from port:" + mTCP_SERVER_PORT +
System.getProperty("line.separator");
//将发送字符串写入上面定义的BufferedWriter中
out.write(outgoingMsg);
//刷新，发送
out.flush();
if(true) break;
}
//关闭socket
socket.close();
}
}catch (InterruptedIOException e){
//超时错误
e.printStackTrace();
}catch (IOException e){
//IO异常
e.printStackTrace();
}finally {
//判定是否初始化ServerSocket对象，如果初始化则关闭serverSocket
if(serverSocket!=null){
try {
serverSocket.close();
}catch (IOException e){
e.printStackTrace();
}
}
}
}
}
3、2、客户端
（1）MainAvtivity.java
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.net.Socket;
public class MainActivity extends AppCompatActivity {
//服务器IP地址
String localhost="192.168.155.4";
//端口号
final int PORT=12345;
/相关布局
EditText send_et;
TextView receive_tv;
TextView send_tv;
Button send_btn;
private void init_view()
{
send_et=findViewById(R.id.et_send_message);
receive_tv=findViewById(R.id.tv_receive_mesage);
send_tv=findViewById(R.id.tv_send_mesage);
send_btn=findViewById(R.id.btn_send);
send_tv.setMovementMethod(ScrollingMovementMethod.getInstance());
receive_tv.setMovementMethod(ScrollingMovementMethod.getInstance());
}
//按钮点击响应事件
public void btn_send_onClick(View view){
ClientThread clientthread=new
ClientThread(localhost,PORT,mHandler,send_et.getText().toString());
clientthread.start();
Log.i("按钮点击事件响应：","客户端线程启动");
}
/*使用主线程的Handler*/
//调用当前线程的Looper
private Handler mHandler=new Handler(Looper.myLooper()){
@Override
public void handleMessage(Message msg){
super.handleMessage(msg);
switch (msg.what){
//用于更新发送消息界面的更新
case 0x01:{
String content=(String)msg.obj;
System.out.println(content);
System.out.println("更新客户端发送内容");
send_tv.append(content);
break;
}
case 0x02:{
//用于更新接收消息界面的更新
String content=(String)msg.obj;
System.out.println(content);
System.out.println("更新客户端接收内容");
receive_tv.append(content);
break;
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init_view();
}
}
（2）ClientThread.java
package com.example.chat_tcp_client;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.UnknownHostException;
public class ClientThread extends Thread {
private String LocalHost;
private int TCP_SERVER_PORT;
private Handler mhandler;
private String msend_message;
public ClientThread(String localhost, int port, Handler handler,String send_message)
{
this.LocalHost=localhost;
this.TCP_SERVER_PORT=port;
this.mhandler=handler;
this.msend_message=send_message;
}
@Override
public void run(){
super.run();
send_receive();
}
private void send_receive(){
try {
//初始化Socket,TCP_SERVER_PORT为指定的端口，int类型
Socket socket=new Socket(LocalHost,TCP_SERVER_PORT);
//获取输入流
BufferedReader in=new BufferedReader(new
InputStreamReader(socket.getInputStream()));
//生成输出流
BufferedWriter out=new BufferedWriter((new
OutputStreamWriter(socket.getOutputStream())));
//生成输出内容（to Server）
String outMsg=System.getProperty("line.separator")+"TCP connecting to
"+TCP_SERVER_PORT+" "+msend_message+System.getProperty("line.separator");
//写入
out.write(outMsg);
//刷新，发送
out.flush();
//使用Handler机制将客户端发送消息用于UI界面更新
send_msg(0x01,outMsg);
//生成输入内容（from Server）
String inMsg=in.readLine()+System.getProperty("line.separator");
Log.i("TCPClient","received:"+inMsg);
//使用Handler机制将客户端接收消息用于UI界面更新
receive_msg(0x02,inMsg);
//关闭连接
socket.close();
}catch (UnknownHostException e){
e.printStackTrace();
}catch (IOException e){
e.printStackTrace();
}
}
private void send_msg(int what,String out_msg){
Message msg=new Message();
msg.what=what;
msg.obj=out_msg;
mhandler.sendMessage(msg);
}
private void receive_msg(int what,String in_msg){
Message msg=new Message();
msg.what=what;
msg.obj=in_msg;
mhandler.sendMessage(msg);
}
}
（3）activity_main.xml布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/border_write"
android:hint="客户端接收的消息" />
<TextView
android:layout_width="match_parent"
android:layout_height="100dp"
android:id="@+id/tv_receive_mesage"
android:scrollbars="vertical"
android:fadeScrollbars="false"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/border_write"
android:hint="客户端发送的消息" />
<TextView
android:layout_width="match_parent"
android:layout_height="100dp"
android:id="@+id/tv_send_mesage"
android:scrollbars="vertical"
android:fadeScrollbars="false"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="内容输入框"
android:background="@drawable/border_write" />
<EditText
android:layout_width="match_parent"
android:layout_height="100dp"
android:id="@+id/et_send_message"
android:hint="输入发送内容"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/btn_send"
android:onClick="btn_send_onClick"
android:text="发送"/>
</LinearLayout>（4）border_write.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<!--实心-->
<solid android:color="@android:color/white"/>
<!--边框-->
<stroke
android:width="0.5dp"
android:color="@android:color/white"/>
<!--圆角-->
<corners android:radius="3dp"/>
<!--边距-->
<padding
android:bottom="5dp"
android:top="5dp"
android:left="5dp"
android:right="5dp"/>
<!--渐变-->
<gradient
android:angle="270"
android:endColor="#FFFF"
android:startColor="#13C7AF"/>
</shape>4、运行结果
（1）服务器端
（2）客户端