JAVA题目笔记（二十五）网络编程综合小练qa!3EF TG6U8.L；

一、多发多收

客户端：

import java.io.*;
import java.net.Socket;
import java.util.Scanner;public class Test1_2 {public static void main(String[] args) throws IOException {//TCP发送端Scanner sc=new Scanner(System.in);String b;//创建Socket对象Socket socket=new Socket("127.0.0.1",1000);OutputStream ops = socket.getOutputStream();//多次发送数据while(true){//从连接通道中获取输出流System.out.print("输入信息：");b=sc.nextLine();ops.write((b+"\r\n").getBytes());ops.flush();if(b.equals("886"))break;}socket.close();}
}

服务器：

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;public class Test1 {public static void main(String[] args) throws IOException {//TCP接收端//创建ServerSocket对象ServerSocket ss=new ServerSocket(1000);//接收数据Socket socket = ss.accept();//获取通道中的输入流InputStreamReader isr=new InputStreamReader(socket.getInputStream());int b;//多发多收while ((b = isr.read()) != -1) {System.out.print((char)b);}socket.close();ss.close();}
}

Tips:

BufferedWriter

OutputStreamWriter这类因为自身带有缓冲区，因此只有当缓冲区填满时或者流关闭时才会向服务器传输数据。不适合多发多收。

二、接收和反馈

客户端：

import java.io.*;
import java.net.Socket;
import java.util.Scanner;public class Test2_2 {public static void main(String[] agrs) throws IOException {//TCP协议发送端//创建Socket对象//在创建对象的同时会连接服务器//如果连接不上，代码会报错Socket socket=new Socket("127.0.0.1",1000);//从连接通道种获取输出流OutputStream ops=socket.getOutputStream();Scanner sc=new Scanner(System.in);//写出数据String s=sc.nextLine();ops.write(s.getBytes());//关闭通道中输出流socket.shutdownOutput();//等待接收端反馈信息BufferedReader br=new BufferedReader(new InputStreamReader(socket.getInputStream()));String str = br.readLine();System.out.println(str);socket.close();}
}

服务器：

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
public class Test2 {public static void main(String[] args) throws IOException {//TCP协议接收端//创建ServerSocket对象ServerSocket ss=new ServerSocket(1000);//监听客户端的链接Socket socket=ss.accept();//从连接通道中获取输入流，读取数据(不能传中文)//使用转换流转化为字符流InputStreamReader isr=new InputStreamReader(socket.getInputStream());//为了读取效率，再套一个缓冲流BufferedReader br=new BufferedReader(isr);String s;while((s=br.readLine())!=null){System.out.println(s);}//关闭通道中的输入流socket.shutdownInput();//反馈//获取通道中的输出流socket.getOutputStream();BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write("已经接收到了信号");bw.close();socket.close();}
}

Tips：

//读取结束标记
socket.shutdownInput();

//写入结束标记
socket.shutdownOutput();通道中的输出流和输入流两边都可以调取并使用

三、上传文件

客户端：

import java.io.*;
import java.net.Socket;public class Test3_2 {public static void main(String[] args) throws IOException {//发送端//创建Socket对象Socket socket=new Socket("127.0.0.1",1000);OutputStream ops=socket.getOutputStream();//根据通道输出流转换成字符流再转换成字符缓冲流BufferedOutputStream bos=new BufferedOutputStream(socket.getOutputStream());//读取本地文件BufferedInputStream bis=new BufferedInputStream(new FileInputStream("src\\MIUI10.jpg"));int len;byte[] bytes=new byte[1024];while((len=bis.read(bytes))!=-1){bos.write(bytes,0,len);bos.flush(); //刷新缓冲区}//本地文件读取结束bis.close();//输出流结束标记socket.shutdownOutput();//接收反馈信号BufferedReader br=new BufferedReader(new InputStreamReader(socket.getInputStream()));String b;while((b=br.readLine())!=null){System.out.println(b);}br.close();socket.close();}
}

服务器：

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;public class Test3 {public static void main(String[] args) throws IOException {//接收端//创建服务器对象ServerSocket ss=new ServerSocket(1000);//通道对象Socket socket = ss.accept();//获取通道的输入流BufferedInputStream bis=new BufferedInputStream(socket.getInputStream());//写入本地文件BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("COPY.jpg"));int len;byte[] bytes=new byte[1024];while((len=bis.read(bytes))!=-1){//拷贝bos.write(bytes,0,len);bos.flush();//刷新缓冲区}bos.close();//读取结束标志socket.shutdownInput();//发送反馈//获取通道中的输出流BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write("文件接收完毕");bw.close();//刷新缓冲区//释放资源socket.close();}
}

四、解决三中重名问题

只需要修改服务器

服务器：

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.UUID;public class Test3 {public static void main(String[] args) throws IOException {//接收端//创建服务器对象ServerSocket ss=new ServerSocket(1000);//通道对象Socket socket = ss.accept();//获取通道的输入流BufferedInputStream bis=new BufferedInputStream(socket.getInputStream());//写入本地文件String name=UUID.randomUUID().toString().replace("-","");BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(name+".jpg"));int len;byte[] bytes=new byte[1024];while((len=bis.read(bytes))!=-1){//拷贝bos.write(bytes,0,len);bos.flush();//刷新缓冲区}bos.close();//读取结束标志socket.shutdownInput();//发送反馈//获取通道中的输出流BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write("文件接收完毕");bw.close();//刷新缓冲区//释放资源socket.close();}
}

Tips：

String name=UUID.randomUUID().toString().replace("-","");
BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(name+".jpg"));UUID类中的randomUUID方法：生成随机且唯一的序列号

五、上传文件（多线程版）

服务器：

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;public class Test5 {public static void main(String[] args) throws IOException {//接收端//创建服务器对象ServerSocket ss=new ServerSocket(1000);while(true){//阻塞状态：等待客户端连接Socket socket = ss.accept();new MyThread(socket).start();}}
}

线程对象：

import java.io.*;
import java.net.Socket;
import java.util.UUID;public class MyThread extends Thread{private Socket socket;public MyThread(Socket socket){this.socket=socket;}@Overridepublic void run() {//通道对象try {//获取通道的输入流BufferedInputStream bis = new BufferedInputStream(this.socket.getInputStream());//写入本地文件String name = UUID.randomUUID().toString().replace("-", "");BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(name + ".jpg"));int len;byte[] bytes = new byte[1024];while ((len = bis.read(bytes)) != -1) {//拷贝bos.write(bytes, 0, len);bos.flush();//刷新缓冲区}bos.close();//读取结束标志this.socket.shutdownInput();//发送反馈//获取通道中的输出流BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(this.socket.getOutputStream()));bw.write("文件接收完毕");bw.close();//刷新缓冲区} catch (IOException e) {throw new RuntimeException(e);} finally {//释放资源if(socket!=null){//避免空指针异常//若socket为null 对其调用close方法，则会导致空指针异常try {this.socket.close();} catch (IOException e) {throw new RuntimeException(e);}}}}
}

六、上传文件（线程池版）

服务器：

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;public class Test6 {public static void main(String[] args) throws IOException {//接收端//创建线程池对象ThreadPoolExecutor pool=new ThreadPoolExecutor(3,//核心线程数量 不能小于016,//最大线程数 不能小于0，最大数量必须要大于等于核心数量60,//空闲线程的最大存活时间TimeUnit.SECONDS,//时间单位new ArrayBlockingQueue<>(3),//任务队列Executors.defaultThreadFactory(),//创建线程工厂new ThreadPoolExecutor.AbortPolicy()  //创建任务的拒绝策略（新建一个类的内部类）);//创建服务器对象ServerSocket ss=new ServerSocket(1000);while(true){//阻塞状态：等待客户端连接Socket socket = ss.accept();//添加入线程池pool.submit(new MyThread(socket));}}
}

七、多人聊天室

客户端：

import java.io.*;
import java.net.Socket;
import java.util.Scanner;public class TalkRoom_client {public static void main(String[] args) throws IOException {//客户端//创建Socket对象Socket socket=new Socket("127.0.0.1",1000);while(true){show();Scanner sc = new Scanner(System.in);String choose = sc.nextLine();if (choose.equals("1")) {//登录选择Login(socket);} else if (choose.equals("2")) {//注册Register(socket);} else {//选择不对System.out.println("无效选择，请输入 1 或 2  ");}}}private static void Register(Socket socket) throws IOException {Scanner sc=new Scanner(System.in);//向服务器传输注册标志SendMessageToClient(socket,"register");while(true){//开始注册流程showRegister();System.out.print("请输入账号：");String account=sc.nextLine();System.out.println("请输入密码：");String password=sc.nextLine();int result=check(account,password);//1 正确   2 账号错误  3 密码错误if(result==1){//正确,进行传输String str=account+"="+password;SendMessageToClient(socket,str);System.out.println("注册成功");break;}else if(result==2){//账号违法System.out.println("账号违法，请重新注册");}else{//密码违法System.out.println("密码违法，请重新注册");}}}public static void TalkToAll(Socket socket) throws IOException {Scanner sc=new Scanner(System.in);System.out.println("开始聊天");while(true){System.out.println("请输入要说的话：");String str=sc.nextLine();SendMessageToClient(socket,str);}}public static int check(String account,String password){if(account.matches("[a-zA-Z]{6,12}")){if(password.matches("[a-zA-Z]\\d{2,7}")){//全对return 1;}else{//密码不对return 3;}}else return 2; //账号不对}public static void Login(Socket socket) throws IOException {Scanner sc=new Scanner(System.in);//字符缓冲流：用于传输账号密码信息BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));//向服务器传输登录标志bw.write("login");bw.newLine();bw.flush();System.out.println("请输入您的账号：");String account = sc.nextLine();bw.write(account);bw.write("&");System.out.println("请输入您的密码:");String password = sc.nextLine();bw.write(password);bw.newLine();bw.flush();//接收反馈String s = br.readLine();System.out.println("结果为："+s);//1 登录成功  2 密码错误 3 账号不存在if("1".equals(s)){System.out.println("登录成功");new ReceiveMessage(socket).start();//开始聊天TalkToAll(socket);}else if("2".equals(s)){System.out.println("密码错误");}else {System.out.println("账号不存在");}}public static void SendMessageToClient(Socket socket,String str) throws IOException {BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write(str);bw.newLine();bw.flush();}public static void show(){System.out.println("=======聊天室========");System.out.println("1、登录");System.out.println("2、注册");System.out.println("请输入您的选择：");}public static void showRegister(){System.out.println("开始注册");System.out.println("账号要求：6~12位,纯字母");System.out.println("密码要求：3~8位,第一位必须为字母,其余纯数字");}
}

服务器：

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;public class TalkRoom_server {public static void main(String[] args) throws IOException {//创建服务器ServerSocket ss=new ServerSocket(1000);//创建一个存放socket的集合来进行统一操作ArrayList<Socket> socketlist=new ArrayList<>();while(true){//等待客户端连接Socket socket = ss.accept();socketlist.add(socket);new ClientThread(socket,socketlist).start();}}
}

客户端线程：

import java.io.*;
import java.net.Socket;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;public class ClientThread extends Thread{static File file=new File("tst.txt"); //存放账号信息的本地文件private Socket socket;private ArrayList<Socket> socketlist;private Map<String,String> map=new HashMap<>();public ClientThread(Socket socket,ArrayList<Socket> socketlist){this.socket=socket;this.socketlist=socketlist;}public void updateMap() throws IOException {//读取本地文件中的账号信息存入集合中BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(new FileInputStream("tst.txt")));String b;while((b=bufferedReader.readLine())!=null){String[] strings = b.split("=");map.put(strings[0],strings[1]);}}@Overridepublic void run() {while(true){try {//接收用户传过来的信息BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));//第一次传输的是选择String choose = br.readLine();switch (choose) {case "login":System.out.println("用户选择登录");//登录操作//先更新本地文件mapupdateMap();login(br, socket, map);break;case "register"://注册操作System.out.println("用户选择注册");register(br,socket,file);break;}} catch (IOException e) {throw new RuntimeException(e);}}}public void register(BufferedReader br,Socket socket,File file) throws IOException {//接收传过来的注册信息String b=br.readLine();//写入本地文件BufferedWriter bufferedWriter=new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file,true)));bufferedWriter.write(b);bufferedWriter.newLine();bufferedWriter.close();//更新本地文件updateMap();}public void login(BufferedReader br,Socket socket,Map<String,String> map) throws IOException {ArrayList<String> list=new ArrayList<>();//获取传输过来的账号密码信息String info=br.readLine();  //account&passwordString[] split = info.split("&");System.out.println("用户输入账号为："+split[0]);System.out.println("用户输入密码为："+split[1]);list.add(split[0]);list.add(split[1]);if(map.get(list.get(0))!=null){//账号存在if(map.get(list.get(0)).equals(list.get(1))){//密码正确System.out.println("用户"+list.get(0)+"登录成功");SendMessageToClient("1");//开始聊天//接收ReceiveMessageFromClient(list.get(0),socketlist);}else {//密码错误System.out.println("密码错误");SendMessageToClient("2");}}else{//根本不存在账号System.out.println("账号不存在");SendMessageToClient("3");}}public void SendMessageToClient(String str,ArrayList<Socket> socketlist) throws IOException {for (Socket s : socketlist) {BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));bw.write(str);bw.newLine();bw.flush();}}public void SendMessageToClient(String str) throws IOException {BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write(str);bw.newLine();bw.flush();}public void ReceiveMessageFromClient(String name,ArrayList<Socket> socketlist) throws IOException {BufferedReader br=new BufferedReader(new InputStreamReader(socket.getInputStream()));String b;while((b=br.readLine())!=null){System.out.println("用户"+name+"发送了信息："+b);//广播给所有用户SendMessageToClient("用户"+name+"发送了信息："+b,socketlist);}}
}