android - 客户端-服务器TCP通讯

服务器应该向客户端发送一条消息“Hello::输入QUIT退出”，然后客户端键入任何文本，服务器回显该客户端的文本，并在其消息之前添加“From server:”。
但是顺序似乎有些困惑，我似乎找不到位置!我整天都在忙!

这是服务器的代码:

    import java.net.*;


public class Server {

    public static void main(String[] args) {

        int nreq = 1;
        try
        {
            ServerSocket sock = new ServerSocket (8080);
            for (;;)
            {
                Socket newsock = sock.accept();
                System.out.println("Creating thread ...");
                Thread t = new ThreadHandler(newsock,nreq);
                t.start();
            }
        }
        catch (Exception e)
        {
            System.out.println("IO error " + e);
        }
        System.out.println("End!");
    }
}

ThreadHandler代码:

    import java.io.*;
import java.net.*;

class ThreadHandler extends Thread {
    Socket newsock;
    int n;

    ThreadHandler(Socket s, int v) {
        newsock = s;
        n = v;
    }

    // @SuppressWarnings("deprecation")
    public void run() {
        try {

            PrintWriter outp = new PrintWriter(newsock.getOutputStream(), true);
            BufferedReader inp = new BufferedReader(new InputStreamReader(
                    newsock.getInputStream()));
            outp.println("Hello :: enter QUIT to exit");
            boolean more_data = true;
            String line;
            while (more_data) {
                line = inp.readLine();
                if (line == null) {
                    more_data = false;
                } else {
                    outp.println("From server: " + line + "\n");
                    if (line.trim().equals("QUIT"))
                        more_data = false;
                }
            }
            newsock.close();
        } catch (Exception e) {
            System.out.println("IO error " + e);
        }

    }
}

和客户端代码:

 import java.io.*;
import java.net.*;
import java.util.Scanner;

public class Client {
    // @SuppressWarnings("deprecation")
    public static void main(String args[]) {
        Scanner scanner = new Scanner(System.in);
        try {
            Socket s = new Socket("localhost", 8080);
            PrintWriter outp = new PrintWriter(s.getOutputStream(), true);
            BufferedReader inp = new BufferedReader(new InputStreamReader(
                    s.getInputStream()));
            boolean more_data = true;
            System.out.println("Established connection");
            String line;
            while (more_data) {
                line = inp.readLine();
                String userInput = scanner.nextLine();
                outp.println(userInput);
                if (line == null) {
                    more_data = false;
                } else
                    System.out.println(line);
            }
            System.out.println("end of while");
        } catch (Exception e) {
            System.out.println("IO error " + e);
        }
    }
}

我正在对其进行测试，因此在将客户端设置为Android手机之后-如果可以的话-

更新:

我已将服务器的代码更改为:

outp.println("Hello :: enter QUIT to exit \n");
        boolean more_data = true;
        String line;
        while (more_data) {
        line = inp.readLine();
        System.out.println("Message '" + line + "' echoed back to client.");// !!
        if (line == null) {
            System.out.println("line = null");
            more_data = false;
        } else {
            outp.println("From server: " + line + ". \n");
            if (line.trim().equals("QUIT"))
                more_data = false;
        }
    }
    newsock.close();
    System.out.println("Disconnected from client number: " + n);

并按照Luis Miguel Serrano的建议在Hello消息的末尾添加了“\n”，并更改了客户方，如下所示:

boolean more_data = true;
        System.out.println("Established connection");
        String line;// = inp.readLine();

        while (more_data) {
            line = inp.readLine();
            System.out.println(line);
            if (line == null) {
                // nothing read
                more_data = false;
            } else
                line = inp.readLine();
            System.out.println(line);
            String userInput = scanner.nextLine();
            if (userInput.trim() == "QUIT") {
                s.close();
                System.out.println("Disconnected from server.");
                more_data = false;
            } else
                outp.println(userInput);

        }
        System.out.println("end of while");

现在，它可以正常工作。

如果有人可以建议我，那么一些Android客户端Java服务器教程将不胜感激。

最佳答案

按照您的评论顺序，这可能是一个冲洗问题。尝试添加以下行:

outp.flush();

后:

outp.println("Hello :: enter QUIT to exit");

写入流时，有时将写入的内容保存在缓冲区中。如果要确保清空缓冲区并实际发送字符串，则需要调用flush()方法。

更新

另外，在服务器的Hello Hello消息的末尾添加“\n”。我认为这将使其起作用。