目录

• 基于TCP/IP协议的通信
• 基于UDP协议的通信
• InetAddress
• 案例演示 （简易聊天室）
• UDP 演示
• 总结

/** * * InetAddressDemo * * */public class InetAddressDemo {    public static void main(String[] args) throws IOException {        InetAddress baidu = InetAddress.getByName("www.baidu.com");        System.out.println(baidu);        System.out.println(baidu.getHostAddress());//获取主机地址        System.out.println(baidu.isReachable(1000));//是否可达        System.out.println("====================================================================================");        InetAddress local = InetAddress.getByAddress(new byte[]{127, 0, 0, 1});        System.out.println(local.getHostName());//获取主机名        System.out.println(local.isReachable(1000));//是否可达    }}

package javaserver.TcpServer;import JAVAClient.TcpClient;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintStream;import java.net.ServerSocket;import java.net.Socket;import java.util.ArrayList;import java.util.Collections;import java.util.List;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;public class tcpServer {    public static ExecutorService threadPool= Executors.newFixedThreadPool(10);    public static List<Socket> socketList= Collections.synchronizedList(new ArrayList<>());    public static void main(String[] args) {////        try {////            //接受客户端的请求//            ServerSocket serverSocket=new ServerSocket(9000);//            while (true){//                Socket socket = serverSocket.accept();//封装了一些客户端的信息//                System.out.println("请求;" + socket.toString());////                PrintStream ps=new PrintStream(socket.getOutputStream());//                ps.println("welcome "+ socket.getInetAddress().getHostAddress());//                socket.close();//            }////        } catch (Exception e) {//            e.printStackTrace();//        }//    }        try {            ServerSocket serverSocket = new ServerSocket(9000);            while (true){                Socket socket = serverSocket.accept();                socketList.add(socket);                threadPool.submit(new ThreadTask(socket));            }        } catch (Exception e) {            e.printStackTrace();        }    }}class  ThreadTask implements  Runnable{    private Socket  socket;    private BufferedReader reader;    public ThreadTask(Socket socket) {        this.socket = socket;        try {            this.reader=new BufferedReader(new InputStreamReader(socket.getInputStream()));        } catch (IOException e) {            e.printStackTrace();        }    }    @Override    public void run() {        try {            String line;            while ((line=reader.readLine())!=null){                for (Socket client: tcpServer.socketList){                    String from=socket.getInetAddress().getHostAddress()+":::"+socket.getPort();                    String content= from+"说"+line;                    new PrintStream(client.getOutputStream()).println(content);                }            }        } catch (Exception e) {            e.printStackTrace();        }    }}

package JAVAClient;import java.io.*;import java.net.Socket;import java.util.Scanner;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;public class TcpClient {    public static ExecutorService threadPool= Executors.newFixedThreadPool(3);    public static void main(String[] args) throws IOException {//        Socket socket=new Socket("127.0.0.1",9000);//        BufferedReader br=new BufferedReader(new InputStreamReader(socket.getInputStream()));//        String s = br.readLine();//        System.out.println(s);        Socket socket=new Socket("127.0.0.1",9000);        threadPool.submit(new ReadTask(socket));        threadPool.submit(new WriteTask(socket));    }}class ReadTask implements Runnable{   private Socket socket;   private BufferedReader reader;    public ReadTask(Socket socket) {        this.socket = socket;        try {            this.reader=new BufferedReader(new InputStreamReader(socket.getInputStream()));        } catch (IOException e) {            e.printStackTrace();        }    }    @Override    public void run() {        try {            String line;            while ((line=reader.readLine())!=null){                System.out.println(line);            }        } catch (Exception e) {            e.printStackTrace();        }    }}class WriteTask implements Runnable{    private Socket socket;    private PrintStream writer;    public WriteTask(Socket socket) {        this.socket = socket;        try {            writer=new PrintStream(socket.getOutputStream());        } catch (IOException e) {            e.printStackTrace();        }    }    @Override    public void run() {        Scanner scanner = new Scanner(System.in);        String line;        while ((line=scanner.nextLine())!=null){            writer.println(line);        }    }}

package javaserver.TcpServer;import java.net.*;import java.util.ArrayList;import java.util.List;import java.util.Scanner;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;public class UdpServer {    public static ExecutorService threadPool= Executors.newFixedThreadPool(10);    public static List<InetSocketAddress> addressesList=new ArrayList<>();    public static void main(String[] args) {        try {            DatagramSocket socket=new DatagramSocket(9001);            // 随时通知            threadPool.submit(new SendTask(socket));            //接受访问 并且记录            byte[] buffer=new byte[1024];            DatagramPacket packet=new DatagramPacket(buffer,buffer.length);            while (true){                socket.receive(packet);                addressesList.add((InetSocketAddress) packet.getSocketAddress());            }        } catch (Exception e) {            e.printStackTrace();        }    }}class SendTask implements Runnable{    private DatagramSocket socket;    public SendTask(DatagramSocket socket) {        this.socket = socket;    }    @Override    public void run() {        try {            Scanner scanner = new Scanner(System.in);            String line;            while ((line= scanner.nextLine())!=null){                for (InetSocketAddress isa:UdpServer.addressesList){                    byte[] buffer=line.getBytes();                    DatagramPacket packet=new DatagramPacket(buffer,buffer.length,isa.getAddress(),isa.getPort());                    socket.send(packet);                }            }        } catch (Exception e) {            e.printStackTrace();        }    }}

package JAVAClient;import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.InetAddress;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;public class UdpClient {    public static ExecutorService threadPool= Executors.newFixedThreadPool(3);    public static void main(String[] args) {        try {            DatagramSocket socket=new DatagramSocket();//            注册             DatagramPacket packet=new DatagramPacket(new byte[]{1},1, InetAddress.getByName("127.0.0.1"),9001);             socket.send(packet);//             接收            threadPool.submit(new ReceiveTask(socket));        } catch (Exception e) {            e.printStackTrace();        }    }}class ReceiveTask implements Runnable{    private DatagramSocket socket;    public ReceiveTask(DatagramSocket socket) {        this.socket = socket;    }    @Override    public void run() {   try {       byte[] buffer=new  byte[1024];       DatagramPacket packet=new DatagramPacket(buffer,buffer.length);       while (true){           socket.receive(packet);           String line =new String(packet.getData(),0, packet.getLength());           System.out.println(line);       }   } catch (Exception e) {       e.printStackTrace();   }    }}