客户端与服务器之间的交互过程解析

Socket 通信

IP地址的组成 32位 由4个8位二进制数组成。

IP&＃61;网络地址&＃43;主机地址

Ipconfig/all       dos命令查看ip

测试网络是否连通

Ping 127.0.0.0(本机地址)看自己的网卡有没有坏

Ping www.baidu.com 看能不能连上广域网

服务器&＃xff1a;性能很好的计算机

端口号&＃xff1a;每一个程序都会有一个唯一的端口号&＃xff0c;程序之间端口号不能一样

Nextline() 一次一行

//服务器

package 客户端一来一回;import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketAddress;
import java.net.SocketException;
import java.util.Scanner;public class send {public static void main(String[] args) {// TODO Auto-generated method stubString con &＃61; "";do {try {Scanner input &＃61; new Scanner(System.in);byte[] buf &＃61; new byte[1024];DatagramPacket dp &＃61; new DatagramPacket(buf, buf.length);System.out.println("服务端已启动&＃xff0c;等待客户端连接..");//创建datagramsocket对象&＃xff0c;接收数据DatagramSocket ds &＃61; new DatagramSocket(8800);ds.receive(dp);//显示接收到的信息String mess &＃61; new String(dp.getData(), 0, dp.getLength());System.out.println(dp.getAddress().getHostAddress() &＃43; "说&＃xff1a;"&＃43; mess);System.out.println("服务器你好&＃xff0c;请输入你的内容");String reply &＃61; input.nextLine();System.out.println("同学b 说:" &＃43; reply);// 创建datagramPacket对象&＃xff0c;封装数据SocketAddress sa &＃61; dp.getSocketAddress();DatagramPacket dpto &＃61; new DatagramPacket(reply.getBytes(),reply.getBytes().length, sa);ds.send(dpto);ds.close();con &＃61; reply;} catch (SocketException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}} while (!con.equals("bye"));}}


//客户端

package 客户端一来一回;import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Scanner;public class Receive {public static void main(String[] args) {// TODO Auto-generated method stubString con&＃61;"";do{try {Scanner input&＃61;new Scanner(System.in);System.out.println("客户端你好&＃xff0c;请输入你的内容");String mess&＃61;input.nextLine();System.out.println("同学a 说:"&＃43;mess);//获取本地主机地址InetAddress ia&＃61;InetAddress.getByName("localhost");// 创建datagramPacket对象&＃xff0c;封装数据DatagramPacket dp&＃61;new DatagramPacket(mess.getBytes(), mess.getBytes().length,ia,8800);//创建datagramsocket对象&＃xff0c;向服务器发送数据DatagramSocket ds&＃61;new DatagramSocket();ds.send(dp);byte[] buf&＃61;new byte[1024];DatagramPacket dpre&＃61;new DatagramPacket(buf, buf.length);//创建datagramsocket对象&＃xff0c;接收数据ds.receive(dpre);String reply&＃61;new String(dpre.getData(),0,dpre.getLength());System.out.println("同学b 说:"&＃43;reply);ds.close();con&＃61;mess;} catch (UnknownHostException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SocketException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}while(!con.equals("bye"));}}