public static void main(String[] args) throws UnknownHostException {InetAdressDemo.getLocalHost();System.out.println("---------------------------");getHostByName("Lenovo-Autumn");}/*** 获取主机ip和主机名* @throws UnknownHostException*/public static void getLocalHost() throws UnknownHostException {//根据InetAddress获取主机名和主机ipInetAddress localHost = InetAddress.getLocalHost();System.out.println(localHost);   //打印:Lenovo-Autumn/192.168.56.1//根据getLocalHost()返回的值获取ip和主机名String hostName = localHost.getHostName();String hostAddress = localHost.getHostAddress();System.out.println(hostName); //打印 Lenovo-AutumnSystem.out.println(hostAddress); //打印 192.168.56.1//根据切割获取主机名和ipString[] str = localHost.toString().split("/");System.out.println(str[0]); //打印 Lenovo-AutumnSystem.out.println(str[1]); //打印 192.168.56.1
    }/*** 根据主机名称获取ip地址* @param otherName  主机名(可以是局域网中的机器名或者是域名或者是ip)* @throws UnknownHostException*/public static void getHostByName(String otherName) throws UnknownHostException {InetAddress otherHost = InetAddress.getByName(otherName);String hostName = otherHost.getHostName();String hostAddress = otherHost.getHostAddress();System.out.println(hostName); //打印 Lenovo-AutumnSystem.out.println(hostAddress); //打印 192.168.56.1System.out.println(otherHost);   //打印:Lenovo-Autumn/192.168.56.1}

/*** 实现udp发送端*  用java.net.DatagramPackage封装数据*  用java.net.DatagramSocket发送数据** 实现步骤*  1.用DatagramPackage对象,封装数据,接受的地址和端口*  2.创建DatagramSocket*  3.调用DatagramSocket对象send方法,发送数据*  4.关闭资源**  DatagramPackage构造函数*    DatagramPacket(byte[] buf, int length, InetAddress address, int port)*  DatagramSocket构造函数*    DatagramSocket()*    方法:send(DatagramPacket d)*  Created by Autumn on 2018/2/5.*/
public class UdpSend {public static void main(String[] args) throws Exception {Scanner scanner = new Scanner(System.in);//获取地址InetAddress inet = InetAddress.getByName("127.0.0.1");//创建DatagramSocket,负责接受和发送数据DatagramSocket ds = new DatagramSocket();while(true){String msg = scanner.nextLine();//创建数据包对象对象byte[] data = msg.getBytes();//封装数据,接受的地址和端口DatagramPacket dp = new DatagramPacket(data,data.length,inet,6000);//发送数据包
            ds.send(dp);if(msg.equals("exit")){break;}}//关闭
        ds.close();}
}/***  实现udp接收端*  用java.net.DatagramPackage 接受数据*  用java.net.DatagramSocket 接受数据包**  步骤*  1.创建DatagramSocket对象,绑定端口号(要和发送端端口一致)*  2.创建字节数组用来接受数据*  3.创建数据对象包DatagramPackage*  4.创建DatagramSocket*    receive(DatagramPackage dp)接受数据,将数据封装如dp中*  5.拆包*    发送端的ip地址(DatagramPackage.get)*    接受到的字节数组*    发送的端口号*  6.关闭资源* Created by Autumn on 2018/2/5.*/
public class UdpReceive {public static void main(String[] args) throws IOException {//创建数据包传输的对象,并绑定端口号DatagramSocket ds = new DatagramSocket(6000);//创建字节数组byte[] data = new byte[1024];while(true){//创建数据包对象,传递字节数组DatagramPacket dp = new DatagramPacket(data,data.length);//调用ds对象的receive接受数据包,receive()有线程阻塞效果会一直等待接受数据
            ds.receive(dp);//获取数据包大小int len = dp.getLength();//获取发送端的ip地址InetAddress sendAddress = dp.getAddress();String sendHostAddress = sendAddress.getHostAddress();//System.out.println(sendHostAddress);//获取发送端端口号int port = dp.getPort();//System.out.println(port);//System.out.println(new String(data));   //直接打印1024个字节的字符串,有很多空格System.out.println(sendHostAddress+":"+port+"    "+new String(data,0,len));   //这样打印没有多余的空格if(new String(data,0,len).equals("exit")){break;}}//关闭
        ds.close();}
}

/*** 实现TCP服务器程序* 表示服务器程序的类java.net.ServerSocket* 构造方法:*      ServerSocket(int port);   传递端口号** Important:必须获得客户端的套接字(Socket)*     方法:Socket accept()*     服务器可以获取到客户端的套接字* Created by Autumn on 2018/2/5.*/
public class TCPServer {public static void main(String[] args) throws IOException {ServerSocket serverSocket = new ServerSocket(8888);//调用服务器套接字对象accept()获取客户端套接字,具有线程等待效果Socket socket = serverSocket.accept();    //这里会阻塞等待连接接入    cmd中telnet 127.0.0.1 8888即可连接//根据获得的客户端的socket获取输入流InputStream inputStream = socket.getInputStream();//根据输入流将数据读入到data中byte[] data = new byte[1024];int len = inputStream.read(data);   //这里会阻塞,等待数据   cmd中ctrl+]进入到telnet操作模式send value发送数据System.out.println(new String(data,0,len));socket.close();serverSocket.close();}
}/*** 实现TCP客户端,连接到服务器* 和服务器实现数据交换* 实现TCP客户端程序的类 java.net.Socket** 构造方法:*      Socket(String host, int port)传递服务器IP和端口号*      注意:构造方法只要运行,就会和服务器进行连接,连接时报,抛出异常**      OutputStream    getOutputStream()  返回套接字的输出流*          作用:将数据输出,输出到服务器*      InputStream    getInputStream()  返回套接字的输入流*          作用:从服务器端读取数据**      客户端服务器数据交换,必须使用套接字对象Socket中的获取的IO刘,自己new的流不行** Created by Autumn on 2018/2/5.*/
public class TCPClient {public static void main(String[] args) throws IOException {//创建Socket对象,连接服务器Socket socket = new Socket("127.0.0.1",8888);//通过客户端的套接字对象Socket方法,获取字节输出流,将数据写向服务器OutputStream out = socket.getOutputStream();out.write("这是一条来客户端的数据".getBytes());socket.close();}
}

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;public class TCPServer {/*同步阻塞*/public static void main(String[] args) throws IOException {ServerSocket serverSocket = new ServerSocket(8888);System.out.println("服务端启动成功...");while(true){/*一次只能处理一个连接,在一个连接没关闭前无法接收第二个连接,在这里开一个框发送数无问题,开放两个框时会出现第二个无反应*/Socket socket = serverSocket.accept();   //这里会阻塞等待连接接入    cmd中telnet 127.0.0.1 8888即代表连接System.out.println("新客户端连接成功....");InputStream inputStream = socket.getInputStream();while(true) {byte[] data = new byte[1024];System.out.println("正在等待数据...");int len = inputStream.read(data);    //这里会阻塞,等待数据，如果直接关闭cmd窗口会因为关闭socket通道导致len返回-1   cmd中ctrl+]进入到telnet操作模式send value发送数据if (len != -1){System.out.println(new String(data, 0,len, "GBK"));   //用GBK是因为CMD窗口命令发送的数据是GBK编码}else{break;}}}//socket.close();//serverSocket.close();//System.out.println("服务器端关闭....");
    }
}

import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;public class TCPServer {/*异步阻塞*/public static void main(String[] args) throws IOException {ExecutorService threadPool = Executors.newCachedThreadPool();   //线程池ServerSocket serverSocket = new ServerSocket(8888);System.out.println("服务端启动成功...");while(true){/*一次只能处理一个连接,在一个连接没关闭前无法接收第二个连接,在这里开一个框发送数无问题,开放两个框时会出现第二个无反应*/System.out.println("等待客户端连接...");final Socket socket = serverSocket.accept();   //这里会阻塞等待连接接入    cmd中telnet 127.0.0.1 8888即代表连接threadPool.execute(new Runnable() {   //启动一个线程public void run() {try {System.out.println("新客户端连接成功....");InputStream inputStream = socket.getInputStream();while(true) {byte[] data = new byte[1024];System.out.println("正在等待数据...");int len = inputStream.read(data);    //这里会阻塞,等待数据，如果直接关闭cmd窗口会因为关闭socket通道导致len返回-1   cmd中ctrl+]进入到telnet操作模式send value发送数据if (len != -1){System.out.println(Thread.currentThread()+new String(data, 0,len, "GBK"));   //用GBK是因为CMD窗口命令发送的数据是GBK编码}else{System.out.println("break循环");break;}}System.out.println("一次Socket连接关闭");} catch (UnsupportedEncodingException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}});}//socket.close();//serverSocket.close();//System.out.println("服务器端关闭....");
    }
}