Socket编程—Client、Server通信

分手后的思念是犯贱 2022-07-14 03:40 226阅读 0赞

### 编写TCP通信程序，服务器端发送字符串到客户端。 ###

ReadClient.java

//ReadClient.java
    import java.io.*;
    import java.net.*;
    
    public class ReadClient {
    	public static void main(String args[]) throws IOException {
    		Socket clientSocket = null;
    		DataOutputStream outbound = null;
    		DataInputStream inbound = null;
    		InputStreamReader inS = null;
    		try {
    			// 与服务器建立连接
    			clientSocket = new Socket("10.10.49.47", 80); // IP地址：10.10.49.47
    			System.out.println("Client1: " + clientSocket);
    			// 初始化流对象
    			outbound = new DataOutputStream(clientSocket.getOutputStream());
    			inbound = new DataInputStream(clientSocket.getInputStream());
    			inS = new InputStreamReader(inbound);
    			// 发送数据
    			outbound.writeBytes("hello\r\n");
    
    			System.out.println("hello"); // 客户端输出"hello"字符串
    			outbound.flush();
    			int c;
    			while ((c = inS.read()) != -1) {
    				System.out.print((char) c);
    			}
    		} catch (UnknownHostException uhe) {
    			System.out.println("UnknownHostException: " + uhe);
    		}
    
    		catch (IOException ioe) {
    			System.err.println("IOException: " + ioe);
    		} finally {
    			// 关闭流及clientSocket
    			inS.close();
    			outbound.close();
    			inbound.close();
    			clientSocket.close();
    		}
    
    	}
    }

SimpleWebServer.java

//SimpleWebServer.java
    import java.io.*;
    import java.net.*;
    
    public class SimpleWebServer {
    	public static void main(String args[]) {
    		ServerSocket serverSocket = null;
    		Socket clientSocket = null;
    		int connects = 0;
    		try {
    
    			// 创建服务器Socket，端口80，限制5个连接
    			serverSocket = new ServerSocket(80, 5);
    			while (connects < 5) {
    				// 等待连接
    				clientSocket = serverSocket.accept();
    				// 操作连接
    				ServiceClient(clientSocket);
    				connects++;
    			}
    			serverSocket.close();
    		}
    
    		catch (IOException ioe) {
    			System.out.println("Errorin SimpleWebServer: " + ioe);
    		}
    	}
    
    	public static void ServiceClient(Socket client) throws IOException {
    		DataInputStream inbound = null;
    		DataOutputStream outbound = null;
    		try {
    			// 获取输入输出流
    			inbound = new DataInputStream(client.getInputStream());
    
    			outbound = new DataOutputStream(client.getOutputStream());
    			StringBuffer buffer = new StringBuffer(
    					"\"http://www.ytu.edu.cn/\"\r\n");
    			String inputLine;
    			while ((inputLine = inbound.readLine()) != null) {
    				// 判断输入为Hello时，输出字符串
    				if (inputLine.equals("hello")) {
    					outbound.writeBytes(buffer.toString());
    					break;
    
    				}
    			}
    		} finally {
    			// 打印清除连接，关闭流及Socket
    			System.out.println("Cleaningup connection: " + client);
    			outbound.close();
    			inbound.close();
    			client.close();
    		}
    	}
    }

运行结果：

![Center][]

注意：

Address already in use: JVM\_Bind 错误 为端口冲突，改变Socket端口直到成功；

变量声明在try外面,main函数里面，否则finally关闭流及Socket 时会出现 变量cannot be resolved 错误；

Unhandled exception type IOException 错误为 未抛出异常，main函数发现错误抛出即可。

[Center]: /images/20220714/1b3ed44b2d8145c5a58a40274bc39ac1.png