企业官网建设流程全解析

基本的通信架构

CS

BS

网络通信三要素

IP地址

• IP地址的代表类是谁？
  InetAddress类

• 如何获取本机IP对象
  public static InetAddress getLocalHost()

• 如何判断与该IP地址对象是否互通？
  public boolean isReachable(int timeout)

端口号

唯一标识正在计算机设备上运行的进程（程序）

协议

传输层的两个通信协议(UDP和TCP)

TCP通信协议的特点是什么样的?

• 它是一种面向连接的可靠通信协议。

• 传输前，采用“三次握手”方式建立连接，点对点的通信，所以可靠。

• 在连接中可进行大数据量的传输。 通信效率较低。

UDP协议的特点是什么

• 用户数据报协议(User Datagram Protocol)
• UDP是面向无连接，不可靠传输的通信协议。
• 速度快，有大小限制一次最多发送64K，数据不安全，易丢失数据

CS

UDP通信

客户端

服务端

TCP通信

客户端

TCP通信，客户端的代表类是谁？
Socket类
public Socket(String host , int port)

TCP通信，如何使用Socket管道发送、接收数据 ?
OutputStream getOutputStream()：获得字节输出流对象（发）
InputStream getInputStream()：获得字节输入流对象（收）

服务端

服务端实现步骤
创建ServerSocket对象，注册服务端端口。
调用ServerSocket对象的accept()方法，等待客户端的连接，并得到Socket管道对象。
通过Socket对象调用getInputStream()方法得到字节输入流、完成数据的接收。
释放资源：关闭socket管道

CS架构(群聊)

端口转发

Client

package TCP; import java.io.DataOutputStream; import java.io.IOException; import java.io.OutputStream; import java.net.*; import java.util.Scanner; public class Client { static void main() throws IOException { InetAddress ip1=InetAddress.getLocalHost(); System.out.println(ip1); Socket socket=new Socket(ip1,8888); Scanner sc=new Scanner(System.in); OutputStream os=socket.getOutputStream(); DataOutputStream dos=new DataOutputStream(os); new ClientReader_Thread(socket).start(); while (true) { String msg=sc.nextLine(); if(msg.equals("exit")){ System.out.println("退出了客户端，欢迎下次光临"); break; } dos.writeUTF(msg); } dos.close(); socket.close(); } }

ClientReader

package TCP; import java.io.DataInputStream; import java.io.IOException; import java.io.InputStream; import java.net.Socket; public class ClientReader_Thread extends Thread{ private Socket socket; public ClientReader_Thread(Socket socket){ this.socket=socket; } @Override public void run() { InputStream is = null; try { is = socket.getInputStream(); } catch (IOException e) { throw new RuntimeException(e); } DataInputStream dis = new DataInputStream(is); while (true) { try { String msg = dis.readUTF(); System.out.println(msg); System.out.println("————————————"); } catch (IOException e) { System.out.println("自己下线了"+socket.getRemoteSocketAddress()); break; } } } }

Server

package TCP; import java.io.DataInputStream; import java.io.IOException; import java.io.InputStream; import java.net.ServerSocket; import java.net.Socket; import java.util.ArrayList; public class Server { public static ArrayList<Socket> onlineSockets=new ArrayList<>(); static void main() throws IOException { System.out.println("服务端已启动"); ServerSocket serverSocket= new ServerSocket(8888); while (true) { Socket socket=serverSocket.accept(); onlineSockets.add(socket); System.out.println("有人上线了"+socket.getRemoteSocketAddress()); SeverReader_Thread thread=new SeverReader_Thread(socket); thread.start(); } } }

ServerReader

package TCP; import java.io.*; import java.net.Socket; public class SeverReader_Thread extends Thread{ private Socket socket; public SeverReader_Thread(Socket socket){ this.socket=socket; } @Override public void run() { InputStream is = null; try { is = socket.getInputStream(); } catch (IOException e) { throw new RuntimeException(e); } DataInputStream dis = new DataInputStream(is); while (true) { try { String msg = dis.readUTF(); System.out.println(msg); sendToall(msg); System.out.println("————————————"); } catch (IOException e) { System.out.println("有人下线了"+socket.getRemoteSocketAddress()); Server.onlineSockets.remove(socket); break; } } } private void sendToall(String msg) throws IOException { for (Socket onlineSocket : Server.onlineSockets) { OutputStream os=onlineSocket.getOutputStream(); DataOutputStream dos=new DataOutputStream(os); dos.writeUTF(msg); dos.flush(); } } }

BS

package BS; import java.io.DataOutputStream; import java.io.IOException; import java.io.OutputStream; import java.net.InetAddress; import java.net.ServerSocket; import java.net.Socket; import java.net.UnknownHostException; public class Server { static void main() throws IOException { InetAddress ip1=InetAddress.getLocalHost(); System.out.println(ip1); ServerSocket serverSocket=new ServerSocket(1145); while (true) { Socket socket=serverSocket.accept(); System.out.println(socket.getRemoteSocketAddress()); new ServerReader_Thread(socket).start(); } } }

package BS; import java.io.DataOutputStream; import java.io.IOException; import java.io.OutputStream; import java.io.PrintWriter; import java.net.ServerSocket; import java.net.Socket; public class ServerReader_Thread extends Thread{ Socket socket=new Socket(); public ServerReader_Thread(Socket socket){ this.socket=socket; } @Override public void run(){ OutputStream os= null; try { os = socket.getOutputStream(); } catch (IOException e) { throw new RuntimeException(e); } PrintWriter printWriter=new PrintWriter(os); printWriter.println("HTTP/1.1 200 OK"); printWriter.println("Content-Type: text/html; charset=UTF-8"); printWriter.println(); printWriter.println("<div>王顺喜欢玩galgame<div>"); printWriter.flush(); try { socket.close(); } catch (IOException e) { throw new RuntimeException(e); } } }