在这段代码中,客户机向服务器发送一个String
服务器将其反转并重新发送给客户端。
但是,客户端没有收到任何字符串。
或者,服务器可能没有收到要反转的字符串。
服务器代码:

public class Serveur {
    public static void main(String[] args) {
        ServerSocket sock = null;
        Socket link = null;
        BufferedReader input = null;
        PrintWriter output = null;

        try {
            sock = new ServerSocket(1234);
            link = sock.accept();
            input = new BufferedReader(new InputStreamReader(link.getInputStream()));
            output = new PrintWriter(link.getOutputStream());
            String str, rstr;
            while(true){
                System.out.println("entered while loop");
                str = input.readLine();
                System.out.println("we received : " + str);
                rstr="";
                for (int i = 0; i < str.length(); i++)
                    rstr = str.charAt(i) + rstr;
                System.out.println("we will send to the client : " + rstr);
                output.print(rstr);
                System.out.println("sent");
            }
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
    }
}

客户代码:
public class Client {

    public static void main(String[] args) {
        Socket sock = null;
        PrintWriter output = null;
        BufferedReader input = null;

        try {
            sock = new Socket(InetAddress.getLocalHost(), 1234);
            output = new PrintWriter(sock.getOutputStream());
            input = new BufferedReader(new InputStreamReader(sock.getInputStream()));
            String str;
            Scanner s = new Scanner(System.in);
            while(true){
                System.out.println("Ecrire une chaine de caractere : ");
                str = s.nextLine();
                System.out.println("i want to reverse : " + str);
                output.println(str);
                       System.out.println("ch is sent");
                       String rr = input.readLine();
                System.out.print(rr);
                       System.out.println("reversed word is received");
            }
        } catch (UnknownHostException ex) {
            System.out.println(ex.getMessage());
        } catch (IOException ex) {
            Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

}

服务器输出:
进入while循环
客户端输出:
特征链:
睾丸
我想逆转:teste
发送ch

最佳答案

您所面临的唯一问题与刷新输出流有关。因此,即使accept方法成功地传递,服务器端在从客户机读取输入的步骤中仍然处于挂起状态。
刷新确保在调用flush()之前写入编写器的任何内容都写入底层流,而不是位于某个内部缓冲区中。
这种方法在几种情况下都很有用:
如果另一个进程(或线程)在写入文件时需要检查该文件,并且另一个进程看到所有最近的写入非常重要。
如果写入过程可能会崩溃,那么重要的是不要丢失对文件的写入。
如果您正在向控制台写入,并且需要确保每个消息一经写入就显示出来
(见:How to use flush for PrintWriter
我相应地更新了你的代码,它正在工作。
更新的服务器代码:

public class Serveur {
    public static void main(String[] args) {
        ServerSocket sock = null;
        Socket link = null;
        BufferedReader input = null;
        PrintWriter output = null;

        try {
            sock = new ServerSocket(9890);
            link = sock.accept();
            input = new BufferedReader(new InputStreamReader(link.getInputStream()));
            output = new PrintWriter(link.getOutputStream());
            String str, rstr;
            while(true){
                System.out.println("entered while loop");
                str = input.readLine();
                System.out.println("we received : " + str);
                rstr="";
                for (int i = 0; i < str.length(); i++)
                    rstr = str.charAt(i) + rstr;
                System.out.println("we will send to the client : " + rstr);
                output.println(rstr);

                output.flush();
                System.out.println("sent");
            }
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
    }

}

更新的客户端代码:
public class Client {
    public static void main(String[] args) {
        Socket sock = null;
        PrintWriter output = null;
        BufferedReader input = null;

        try {
            sock = new Socket(InetAddress.getLocalHost(), 9890);
            output = new PrintWriter(sock.getOutputStream());
            input = new BufferedReader(new InputStreamReader(sock.getInputStream()));
            String str;
            Scanner s = new Scanner(System.in);
            while(true){
                System.out.println("Ecrire une chaine de caractere : ");
                str = s.nextLine();
                System.out.println("i want to reverse : " + str);
                output.println(str);
                output.flush();
                       System.out.println("ch is sent");
                       String rr = input.readLine();
                System.out.print(rr);
                       System.out.println("reversed word is received");
            }
        } catch (UnknownHostException ex) {
            System.out.println(ex.getMessage());
        } catch (IOException ex) {
            //Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
        }
}

}

还有“世界程序员你好”这句话的插图。
java - java中的TCP套接字-LMLPHP

关于java - java中的TCP套接字,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/42890816/

10-11 04:03