TCP直连接Socket与ServerSocket,先看代码
服务端:Server.java
package com.socketBio;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
/**
* Created by BaiTianShi on 2018/8/29.
*/
public class Server {
final static int PORT = 8765;
public static void main(String[] args) {
ServerSocket server = null;
while(true){
try {
//创建服务端
server = new ServerSocket(PORT);
System.out.println("server start");
//服务端阻塞,监听客户端连接,一旦有客户端连接就能获取到这个客户端的socket
Socket socket = server.accept();
//每当有客户端请求的时候就创建一个线程,这个线程启动色事先设计好的ServerHandler的run方法
new Thread( new ServerHandler(socket)).start();
} catch (IOException e) {
e.printStackTrace();
}finally {
if(server != null){
try {
//关闭
server.close();
} catch (IOException e) {
e.printStackTrace();
}
}
server = null;
}
}
}
}
服务端处理程序:ServerHdndler.java
package com.socketBio;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
/**
* Created by BaiTianShi on 2018/8/29.
*/
public class ServerHandler implements Runnable {
private Socket socket;
public ServerHandler(Socket socket) {
//构造方法中一定要传入客户端请求的socket才能读取其中的信息或向其写入
this.socket = socket;
}
@Override
public void run() {
System.out.println("运行hanndler的run方法");
//缓冲字符流
BufferedReader reader = null;
//打印输出流
PrintWriter out = null;
try {
//使用输入流声明一个缓冲字节输入流再包装成一个缓冲字符输入流
reader = new BufferedReader( new InputStreamReader( this.socket.getInputStream() ));
//通过输出字符流声明一个打印输出流
out = new PrintWriter(this.socket.getOutputStream(),true);
String body = null;
while(true){//轮询的关键点1
body = reader.readLine();//轮询的关键点2
if(body == null) break;
System.out.println("Server :" + body);
out.println("服务器端返回给客户端的响应数据.");
}
} catch (IOException e) {
e.printStackTrace();
}finally {
if(reader != null){
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(out != null){
try {
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}
if(socket != null){
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
socket = null;
}
}
}
客户端:Client.java
package com.socketBio;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
/**
* Created by BaiTianShi on 2018/8/29.
*/
public class Client {
final static String ADDRESS = "127.0.0.1";
final static int PORT = 8765;
public static void main(String[] args) {
Socket socket= null;
BufferedReader in = null;
PrintWriter out = null;
try {
socket = new Socket(ADDRESS,PORT);
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new PrintWriter(socket.getOutputStream(),true);
out.println("客户端client1向服务器发送请求测试数据");
String response = in.readLine();
System.out.println("Client:"+ response);
} catch (IOException e) {
e.printStackTrace();
}finally {
if(in != null) try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
if(out != null)out.close();
if(socket != null) try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
socket = null;
}
}
}
启动server:
启动client:
server端监测到client建立连接后:
但是,这样的的运行过程是每当有客户端请求的时候都会启动一个线程,会占用过多的资源。如果client与server建立的连接很多,可能耗尽机器资源。
补充知识:
网络编程的基本模型是client/server模型,即服务端 绑定某个端口进行监听,而客户端通过制定ip和端口号向服务端发送连接请求。通过三次握手建立连接若连接成功,则客户端就可与服务端进行通信。
三次握手:参见: https://mp.youkuaiyun.com/postedit/82230273
在jdk105之前,采用伪异步的方式避免Server Scoket建立过多的线程处理客户端的请求,其内部维护着一个线程池,将客户端请求建立的socket封装成一个任务Task(实现Runnable)对象,把任务对象交给线程池管理,并配置响应的阻塞队列BlockingQueue用于缓冲任务对象。可以在线程中设置处理Client建立连接Scoket的线程池最大数量,这样就避免了无线创建子线程而造成系统资源耗尽。
Clien.java
package com.scoketExecutorBio;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
/**
* Created by BaiTianShi on 2018/8/30.
*/
public class Client {
private final static String ADDRESS="127.0.0.1";
private final static int PORT= 8764;
public static void main(String[] args) {
BufferedReader in = null;
PrintWriter out = null;
Socket socket = null;
try {
socket = new Socket(ADDRESS,PORT);
in= new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new PrintWriter(socket.getOutputStream(),true);
out.println("客户端发送的请求");
String body = in.readLine();
System.out.println("客户端接收到的响应:"+body);
} catch (IOException e) {
e.printStackTrace();
}finally {
if(in != null){
try {
in.close();
} catch (Exception e1) {
e1.printStackTrace();
}
}
if(out != null){
try {
out.close();
} catch (Exception e2) {
e2.printStackTrace();
}
}
if(socket != null){
try {
socket.close();
} catch (Exception e3) {
e3.printStackTrace();
}
}
socket = null;
}
}
}
server.java
在srever使用自定义HandlerExeuctorPool,通过构造函数core和max设置核心线程数和最大线程数。服务端监听客户端请求连接的方式是通过ServerScoket.accept()方法监听,一旦有连接,马上获取到次客户端套接字(Scoket),并将此Socket传入封装好的Task任务中,开启线程通过处理Scoket,可读客户端传过来的数据,亦可向客户端写数据。
package com.scoketExecutorBio;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
/**
* Created by BaiTianShi on 2018/8/30.
*/
public class Server {
static final String ADDRESS = "127.0.0.1";
static final int PORT = 8764;
public static void main(String[] args) {
Socket socket = null;
ServerSocket server = null;
System.out.println("服务端:"+ADDRESS+":"+PORT+"等待客户端连接中");
HandlerExecutor executorService = new HandlerExecutor(Runtime.getRuntime().availableProcessors(),20);
try {
server = new ServerSocket(PORT);
while (true){
socket = server.accept();
System.out.println("服务端接收到客户端连接");
executorService.execute( new ServerHandler(socket));
}
} catch (IOException e) {
e.printStackTrace();
}finally {
try {
if(null != socket){
socket.close();
}
} catch (IOException e) {
e.printStackTrace();
}
server = null;
}
}
}
HandlerExeuctorPool.java
package com.scoketExecutorBio;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
* Created by BaiTianShi on 2018/8/30.
*/
public class HandlerExecutor{
private ExecutorService executorService;
public HandlerExecutor(int core, int max) {
executorService = new ThreadPoolExecutor(core,max,120L, TimeUnit.SECONDS, new LinkedBlockingDeque());
}
public void execute(Runnable command) {
executorService.execute(command);
}
}
其中涉及的 new threadPoolExecutor()的方法使用详解见:https://mp.youkuaiyun.com/postedit/81917146
serverHandler.java
在server.java代码中,通过new ServerHandler(socket)将监听到的客户端socket传递给了ServerHandler,ServerHandler实现了Runnable接口,在run()方法中获取Client端传递给来的数据流,经过处理转换后输出。
启动server:
启动client:
启动clinet后,服务端的相应