Java实现TCP客户端和服务器端相互通信_java tcp client

解决TCP客户端和服务器端通信读不到数据的问题

 解决：

服务器端和客户端读完后加上client.shutdownInput();

服务器端和客户端写完后加上client.shutdownOutput();

服务器端代码：

public class TCPTestServer2 {
    public static void main(String[] args) throws IOException {
 
        System.out.println("---------------服务器--------------");
        ServerSocket server = new ServerSocket(9999);
 
        Socket client = server.accept();
        System.out.println("有一个用户连接。。。。。。。");
 
        InputStream is = client.getInputStream();
 
        byte[] msg = is.readAllBytes();
 
        System.out.println(new String(msg)); 
 
        is.close();
        client.close();
        server.close();
 
    }
 
}

客户端代码：

public class TCPTestClient2 {
    public static void main(String[] args) throws IOException {
        System.out.println("-------------客户端------------");
 
        Socket client = new Socket("127.0.0.1", 9999);
 
        Scanner sc = new Scanner(System.in);
 
        byte[] msg = sc.nextLine().getBytes();
        OutputStream os = client.getOutputStream();
 
        os.write(msg);
 
        os.flush();
        os.close();
        client.close();
 
    }
}

运行服务器端再运行客户端，在客户端中输入要发送的信息，回车

服务器收到信息，over

 然后！！！！！！！！！！！！！！！

想让服务器端回信息，结果翻车了。。。。。。

翻车全过程↓

客户端代码:

加了一个

        InputStream is = client.getInputStream();
        System.out.println(new String(is.readAllBytes()));

用来读服务器端发过来的信息

public class TCPTestClient2 {
    public static void main(String[] args) throws IOException {
        System.out.println("-------------客户端------------");
 
        Socket client = new Socket("127.0.0.1", 9999);
 
        Scanner sc = new Scanner(System.in);
 
        byte[] msg = sc.nextLine().getBytes();
        OutputStream os = client.getOutputStream();
 
        os.write(msg);
 
        InputStream is = client.getInputStream();
        System.out.println(new String(is.readAllBytes()));
 
        is.close();
        os.flush();
        os.close();
        client.close();
 
    }
}

服务器端：

只是加了个输出流

public class TCPTestServer2 {
    public static void main(String[] args) throws IOException {
 
        System.out.println("---------------服务器--------------");
        ServerSocket server = new ServerSocket(9999);
 
        Socket client = server.accept();
        System.out.println("有一个用户连接。。。。。。。");
 
        InputStream is = client.getInputStream();
        OutputStream os = client.getOutputStream();
 
        byte[] msg = is.readAllBytes();
 
        System.out.println(new String(msg));
 
 
        Scanner sc = new Scanner(System.in);
 
        byte[] msg2 = sc.nextLine().getBytes();
 
        os.write(msg2);
 
        os.flush();
        os.close();
        is.close();
        client.close();
        server.close();
 
    }
 
}

运行，程序未停止运行且服务器端也没有输出，客户端发过来的消息

也就是System.out.println(new String(msg));没执行到

package homework0526.login1;
 
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
 
public class TCPTestServer2 {
    public static void main(String[] args) throws IOException {
 
        System.out.println("---------------服务器--------------");
        ServerSocket server = new ServerSocket(9999);
 
        Socket client = server.accept();
        System.out.println("有一个用户连接。。。。。。。");
 
        InputStream is = client.getInputStream();
        OutputStream os = client.getOutputStream();
 
        byte[] msg = is.readAllBytes();
        client.shutdownInput();
 
        String s = new String(msg);
 
        System.out.println(s);
 
 
        Scanner sc = new Scanner(System.in);
 
        byte[] msg2 = sc.nextLine().getBytes();
 
        os.write(msg2);
        client.shutdownOutput();
 
 
        os.flush();
        os.close();
        is.close();
        client.close();
        server.close();
 
    }
 
}

 

应该也许的原因：

 解决：

服务器端和客户端读完后加上client.shutdownInput();

服务器端和客户端写完后加上client.shutdownOutput();

服务器端：

public class TCPTestServer2 {
    public static void main(String[] args) throws IOException {
 
        System.out.println("---------------服务器--------------");
        ServerSocket server = new ServerSocket(9999);
 
        Socket client = server.accept();
        System.out.println("有一个用户连接。。。。。。。");
 
        InputStream is = client.getInputStream();
        OutputStream os = client.getOutputStream();
 
        byte[] msg = is.readAllBytes();
        client.shutdownInput();
 
        String s = new String(msg);
 
        System.out.println(s);
 
        Scanner sc = new Scanner(System.in);
 
        byte[] msg2 = sc.nextLine().getBytes();
 
        os.write(msg2);
        client.shutdownOutput();
 
 
        os.flush();
        os.close();
        is.close();
        client.close();
        server.close();
 
    }
 
}

客户端：

package homework0526.login1;
 
import java.io.*;
import java.net.Socket;
import java.util.Scanner;
 
public class TCPTestClient2 {
    public static void main(String[] args) throws IOException {
 
        while (true) {
            System.out.println("-------------客户端------------");
 
            Socket client = new Socket("127.0.0.1", 9999);
 
            Scanner sc = new Scanner(System.in);
 
            byte[] msg = sc.nextLine().getBytes();
            OutputStream os = client.getOutputStream();
 
            os.write(msg);
            client.shutdownOutput();
 
 
            InputStream is = client.getInputStream();
            System.out.println(new String(is.readAllBytes()));
            client.shutdownInput();
 
 
            is.close();
            os.flush();
            os.close();
            client.close();
        }
 
    }
}