JAVA BIO 服务器与客户端实现示例

package com.stevex.app.bio;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

import javax.net.ServerSocketFactory;

public class XiaoNa {
public static void main(String[] args){
XiaoNa xiaona = new XiaoNa();

ServerSocket serverSocket = null;
Socket socket = null;

try {
//可以设置客户连接请求队列的长度，比如5，队列长度超过5后拒绝连接请求
//serverSocket = ServerSocketFactory.getDefault().createServerSocket(8383, 5);
serverSocket = ServerSocketFactory.getDefault().createServerSocket(8383);

while(true){
try{
//监听直到接受连接后返回一个新Socket对象
socket = serverSocket.accept();//阻塞
//new一个线程处理连接请求
new Thread(xiaona.new Worker(socket)).start();;
}
catch (Throwable e) {	//防止发生异常搞死服务器
e.printStackTrace();
}
}
} catch (IOException e) {
e.printStackTrace();
}
finally{
try {
if(socket != null){
socket.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}

private static String getAnswer(String question){
String answer = null;

switch(question){
case "who":
answer = "我是小娜";
break;
case "what":
answer = "我是来帮你解闷的";
break;
case "where":
answer = "我来自外太空";
break;
default:
answer = "请输入 who， 或者what， 或者where";
}

return answer;
}

private class Worker implements Runnable{
private Socket socket;

public Worker(Socket socket){
this.socket = socket;
}

@Override
public void run() {
BufferedReader reader = null;
PrintWriter writer = null;

try {
reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));

writer = new PrintWriter(socket.getOutputStream());

String question = reader.readLine();//没有内容会阻塞

while(!question.equals("OVER")){
String answer = getAnswer(question);
writer.println(answer);
question = reader.readLine();
}

writer.println("OVER");//OVER作为操作完成暗号
writer.flush();

if(writer != null){
writer.close();
}

if(reader != null){
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}

}
}

package com.stevex.app.bio;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

public class Client {
public static void main(String[] args) {
Client c = new Client();

//种20个线程发起Socket客户端连接请求
for(int i=0; i<20; i++){
new Thread(c.new Worker()).start();
}
}

private class Worker implements Runnable{

@Override
public void run() {
Socket socket = null;
BufferedReader reader = null;
PrintWriter writer = null;

try {
//创建一个Socket并连接到指定的目标服务器
socket = new Socket("localhost", 8383);

reader = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
writer = new PrintWriter(socket.getOutputStream());

writer.println("who");
writer.println("what");
writer.println("where");
writer.println("OVER");//OVER作为操作完成暗号
writer.flush();

String answer = reader.readLine();	//没有内容会阻塞
while(! answer.equals("OVER")){
System.out.println(Thread.currentThread().getId() + "---Message from server:" + answer);
answer = reader.readLine();
}

} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (writer != null) {
writer.close();
}

if (reader != null) {
reader.close();
}

if (socket != null) {
socket.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}

}
}