网络基础编程:TCP协议

import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class TcpEchoServer {
    private ServerSocket serverSocket=null;
    private ExecutorService service= Executors.newCachedThreadPool();
    //在创建socket的同时,创建端口号
    public TcpEchoServer(int port) throws IOException {
        serverSocket=new ServerSocket(port);
    }
    //启动服务器
    public void start() throws IOException {
        System.out.println("启动服务器!");
        while(true){
            //1:处理客户端的连接,由于TCP是有连接的,服务器保存客户端的信息,客户端保存服务器的连接
            Socket clientSocket = serverSocket.accept();
            //通过上面产生的Socket对象和对方进行网络通信
//            Thread t=new Thread(()->{
//                try {
//                    processConnection(clientSocket);
//                } catch (IOException e) {
//                    throw new RuntimeException(e);
//                }
//            });
//            t.start();
            service.submit(new Runnable() {
                @Override
                public void run() {
                    try {
                        processConnection(clientSocket);
                    } catch (IOException e) {
                        throw new RuntimeException(e);
                    }
                }
            });
        }
    }
    //通过这个方法来处理一个连接的逻辑
    public void processConnection(Socket clientSocket) throws IOException {
        //通过这两个方法获取客户端的IP地址和端口号
        System.out.printf("[%s:%d] 客户端上线!\n",clientSocket.getInetAddress().toString(),clientSocket.getPort());
        //接下来就可以读取请求,根据请求计算响应,返回响应三步走
        //Socket对象内部包含了两个字节流对象,就可以把这俩字节流对象获取到,完成后续的读写工作
        try(InputStream inputStream=clientSocket.getInputStream();
            OutputStream outputStream=clientSocket.getOutputStream();){
            //一次连接中,可能会涉及到多次请求.响应
            while(true){
                //1:读取请求并解析,为了读取方便,使用Scanner
                Scanner scanner=new Scanner(inputStream);
                if(!scanner.hasNext()){
                    //读取完毕,客户端下线
                    System.out.printf("[%s:%d] 客户端下线!\n",clientSocket.getInetAddress().toString(),clientSocket.getPort());
                    break;
                }
                //客户端发过来的请求,是文本数据,同时,还得带有空白符  next:代表一直读,一直读到空白符(换行/回车/空格/制表符/翻页符)结束
                String  request=scanner.next();
                //2.根据请求计算响应
                String response = process(request);
                //3.把响应返回给客户端,
                PrintWriter writer=new PrintWriter(outputStream);
                //此处使用PrintWriter的println方法,把响应返回给客户端
                writer.println(response);
                writer.flush();//刷新缓冲区,提高程序的效率
                //日志:打印请求详情
                System.out.printf("[%s:%d] req:%s,resp:%s\n",clientSocket.getInetAddress().toString(),clientSocket.getPort(),request,response);
            }
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            clientSocket.close();
        }
    }
   public String process(String request){
        return request;
   }
    public static void main(String[] args) throws IOException {
       TcpEchoServer tcpEchoServer=new TcpEchoServer(9090);
       tcpEchoServer.start();
    }
}

public class TcpEchoClient {
    private Socket socket=null;
    public TcpEchoClient(String serverIp,int serverport) throws IOException {
        //与完成了TCP客户端的建立,此时客户端通过new获得服务器的IP地址和端口号
        socket=new Socket(serverIp,serverport);
    }
    public void start(){
        System.out.println("客户端启动");
        Scanner scannerConsole=new Scanner(System.in);
        try(InputStream inputStream=socket.getInputStream();
            OutputStream outputStream=socket.getOutputStream()) {
            while(true){
              //1:从控制台输入一个字符串
                System.out.println("->");
                String request=scannerConsole.next();
              //2:构造请求,发送给服务器-->利用printWriter进行包装,将输出的进行打包,同时将从控制台输入的传递给服务器
                PrintWriter printWriter=new PrintWriter(outputStream);
                //使用println带上换行,后续服务器读取请求,就可以使用scanner.next来获取了
                printWriter.println(request);
                printWriter.flush();
                //3:从服务器读取响应,并进行处理
                Scanner scannerNetwork=new Scanner(inputStream);
                String respnse= scannerNetwork.next();
                //4:打印响应
                System.out.println(respnse);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) throws IOException {
      TcpEchoClient tcpEchoClient=new TcpEchoClient("127.0.0.1",9090);
      tcpEchoClient.start();
    }
}