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使服务器等待来自两个不同控制器的输入

server javafx sockets java

-2

JimBelushi2 · 技术社区 · 7 年前

我制作了一个客户机-服务器应用程序,服务器必须向客户机发送一个电子邮件列表,在将该列表加载到列表视图后,可以通过菜单栏删除它们。在客户机中,所有这些操作都是在数据模型中进行的(我遵循MVC模式)。这是服务器:

class ThreadedEchoHandler implements Runnable {

    private Socket incoming;

    private String nomeAccount = "";

    public void run() {
        try {
            incoming = s.accept();
        } catch (IOException ex) {
            System.out.println("Unable to accept requests");
        }
        contenutoTextArea.append("Connected from: " + incoming.getLocalAddress() + "\n");
        textarea.setText(contenutoTextArea.toString());
        try {
            //PHASE 1: The server receives the email
            try {
                BufferedReader in = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
                nomeAccount = in.readLine();
            } catch (IOException ex) {
                System.out.println("Not works");
            }

            //PHASE 2: I'm getting all the emails from the files
            File dir = new File("src/server/" + nomeAccount);
            String[] tmp = new String[100];
            int i = 0;
            for (File file : dir.listFiles()) {
                if (file.isFile() && !(file.getName().equals(".DS_Store"))) {
                    try (BufferedReader br = new BufferedReader(new FileReader(file))) {
                        String line;
                        while ((line = br.readLine()) != null) {
                            tmp[i++] = line;
                        }
                    } catch (IOException ex) {
                        System.out.println("Cannot read from file");
                    }
                }
            }

            //PHASE 3: The server sends the ArrayList to the client
            PrintWriter out = new PrintWriter(incoming.getOutputStream(), true);
            for (int j = 0; j < i; j++) {
                out.println(tmp[j]); // send the strings to the client
            }
        } catch (IOException ex) {
            System.out.println("Cannot send the strings to the client");
        }

        //PHASE 4: Here I loop and wait for the client choise
        BufferedReader in;
        String op;
        try {
            in = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
            while ((op = in.readLine()) != null) {                   
                if (op.equals("Elimina")) {
                    String tmp = in.readLine();
                    File file = new File("src/server/" + nomeAccount + "/" + tmp + ".txt");
                    file.delete();
                } else if (op.equals("Invia")) {
                    //...
                } else {
                    //...
                }
            }
        } catch (IOException ex) {
            System.out.println("Non so");

        } finally {
            try {
                incoming.close();
            } catch (IOException ex) {
                System.out.println("Cannot closing the socket");
            }
        }
    }
}

以下是客户的方法:

public void loadData() throws IOException, ClassNotFoundException, ParseException {

    try {
        s = new Socket("127.0.0.1", 5000);
        ArrayList<Email> email = new ArrayList<Email>();
        DateFormat format = new SimpleDateFormat("dd/MM/yyyy");
        Date data;

        /* PHASE 1: The client sends a string to the server */
        //try {
            PrintWriter out = new PrintWriter(s.getOutputStream(), true);
            out.println(account); // send the account name to server

            /* PHASE 2: The client receives the ArrayList with the emails */
            BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
            String line;
            String message[] = new String[5];
            for (int j=0; (line = in.readLine()) != null;) {
                message[j++] = line;
                if (j==5) {
                    data = format.parse(message[3]);
                    email.add(new Email((Integer.parseInt(message[0])), message[1], account, message[2], message[4], data));
                    j=0;
                }
            }

            //Casting the arrayList
            emailList = FXCollections.observableArrayList(email);

            //Sorting the emails
            Collections.sort(emailList, (Email o1, Email o2) -> {
                if (o1.getData() == null || o2.getData() == null) {
                    return 0;
                }
                return o1.getData().compareTo(o2.getData());
            });

        /*} finally {
            s.close();*/
        //}
    } catch (SocketException se) {
        emailList.setAll(null, null);
    }
}

public void deleteMail(Email da_elim) throws IOException {
    int id_del = da_elim.getID();
    emailList.remove(da_elim);
    PrintWriter out = new PrintWriter(s.getOutputStream(), true);
    out.println("Elimina");
    out.println(id_del);
}

服务器的阶段1、2、3用于上传电子邮件,并使用loadData()方法。没有第四阶段,这个程序就可以工作。现在,如果我编写了这个循环,客户端的GUI就不会加载,我也不能按DELETE按钮(这会使输入在循环中嵌入一些内容(在这个过程中是文件的删除)。为什么客户端即使是两个不同的线程也不加载?为什么没有这个循环呢?

编辑:实现了Listener类但仍然不起作用

//PHASE 4: Here I loop and wait for the client choise      
        BufferedReader in;
        String op;
        try {
            in = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
            /*while ((op = in.readLine()) != null) {
                System.out.println("OP: " + op);
                if (op.equals("Elimina")) {
                    String tmp = in.readLine();
                    contenutoTextArea.append("Ho eliminato la mail ").append(tmp).append(" \n");
                    textarea.setText(contenutoTextArea.toString());
                    File file = new File("src/server/" + nomeAccount + "/" + tmp + ".txt");
                    file.delete();
                }
            }*/
            Listener lis = new Listener(in, new LinkedBlockingQueue<String>());
            lis.run();
            System.out.println("bbbbb");
        } catch (IOException ex) {
            System.out.println("Unable to read messages");
        } finally {
            try {
                incoming.close();
            } catch (IOException ex) {
                System.out.println("Cannot close the socket");
            }
        }

2 回复 | 直到 7 年前

kszulchs 7 年前

我认为您应该运行jvisualvm(它是一个在jdk的/bin/location中安装了jdk的工具)并查找您在服务器上创建的线程生命周期。还要检查你的线程是否没有通过代码,只是结束了他的生命跳过等待客户端。

这个线程与客户端有什么联系吗?因为你不能运行客户端应用程序。他们分开了吗?我想到的另一个想法是

Platform.runLater(()->{
});

如果您的客户机GUI在JavaFX中。如果要创建GUI、更改字段中的值以及在GUI上执行的任何操作,请使用它。也许您的服务器正在等待用户的响应,在构建GUI之后呢?所以你不能按删除按钮。

HamBone41801 7 年前

我目前无法发表评论,因此无法要求澄清,但我认为我正确地解释了问题所在。”当程序进入等待两个控制器输入的循环时,程序挂起。假设我正确地理解了这一部分,最有可能的罪魁祸首是缓冲读取器无限期地挂起,因为它没有接收输入。当我第一次遇到这个问题时,我把它放到它自己的“receiver”类中,并使用一个队列将它接收到的任何内容总线到主类中的循环。我的代码看起来像这样:

import java.io.BufferedReader;
import java.io.IOException;
import java.util.concurrent.BlockingQueue;

public class Listener implements Runnable
{
    private BufferedReader br;
    private BlockingQueue<String> q;
    private boolean shouldClose = false;

    public Listener(BufferedReader br, BlockingQueue<String> q)
    {
        this.q = q;
        this.br = br;
    }

    public void run()
    {
        loop();
        System.out.println("listener has stopped");
    }

    public void loop()
    {
        String line = "";

        try
        {
            while((line = br.readLine()) != null && !shouldClose)
            {
                q.put(line);
            }
        }
        catch (IOException | InterruptedException e)
        {
            e.printStackTrace();
        }
    }

    public void shutdown()
    {
        shouldClose = true;
    }
}

抱歉,如果我有任何误解,或错过了你的代码。