當我嘗試中斷線程時，JFrame凍結

Question

在本練習中，我有3個類，一個Provider（Thread）不斷提供存儲在LinkedList內的Integer產品，因此我遇到了這個問題。 一旦大小至少達到10，零售商（線程）就可以全部購買。 還有負責協調線程的分發服務器。 產品顯示在JFrame上，然后當我單擊“停止”按鈕時，每個線程都停止，每個零售商都告訴他們購買了多少產品。

編輯：忘了提出問題了，每當我單擊“停止”按鈕時，應用程序凍結，我什至無法關閉JFrame窗口，不明白為什么。

 public class Distributor {

    private JTextField textfield = new JTextField();
    private LinkedList<Integer> productList = new LinkedList<Integer>();
    private JFrame frame = new JFrame("Window");
    private JButton btn = new JButton("Stop");
    private Thread provider = new Thread(new Provider(this));
    private LinkedList<Thread> retailerList = new LinkedList<Thread>();

    private void addRetailer(int num) {
        for (int i = 0; i < num; i++)
            retailerList.add(new Thread(new Retailer(i, this)));
    }

    public Distributor() {
        frame.setSize(300, 200);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);
        frame.add(textfield);
        frame.add(btn, BorderLayout.SOUTH);
        addRetailer(2);


        btn.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    provider.interrupt();
                    provider.join();
                    System.out.println(provider.isAlive());

                    for (Thread t : retailerList) {
                        t.interrupt();
                        t.join();
                        System.out.println(t.isAlive());
                    }
                } catch (InterruptedException e1) {
                    e1.printStackTrace();
                }
            }
        });
    }

    public void execute() {
        frame.setVisible(true);
        provider.start();
        for (Thread t : retailerList)
            t.start();
    }

    // Keeps providing products, and notifies retailers when there are 10 products
    public synchronized void provide(int product) {
        textfield.setText(productList.toString());
        productList.add(product);
        if (productList.size() == 10)
            notifyAll();
    }

    // Sells all the products if there are at least 10 to sell.
    public synchronized int sell() throws InterruptedException {
        while (productList.size() < 10)
            wait();

        int total = productList.size();
        notifyAll();
        textfield.setText(productList.toString());
        productList.clear();
        return total;
    }
}

Provider類：

public class Provider implements Runnable {
private Distributor distribuidor;
private int total = 0;

public Provider(Distributor distribuidor) {
    super();
    this.distribuidor = distribuidor;
}

@Override
public void run() {
    while (!Thread.interrupted()) {
        try {
            distribuidor.provide((int) (Math.random() * 10) + 1);
            Thread.sleep(10);
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
    System.out.println("Provider Interrupted");
 }
}

零售商類別：

public class Retailer implements Runnable {

private Distributor distributor;
private int total = 0;
private int id;

public Retailer(int id, Distributor distributor) {
    super();
    this.id = id;
    this.distributor = distributor;
}

@Override
public void run() {
    while (!Thread.interrupted()) {
        try {
            total += distributor.sell();
            Thread.sleep(10);
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
    System.out.println("Retailer id: " + id + " bought: " + total + " products");
 }
}

和主類：

public class Main {
    public static void main(String[] args) {
        Distributor distributor = new Distributor();
        distributor.execute();
    }
}

Answer 1

問題是您的Thread實際上永遠不會停止，並且EDT也被阻止。

我建議您使用布爾值來停止Provider內的無限循環。

---

提供者

class Provider implements Runnable {
    private Distributor distribuidor;
    private int total = 0;
    private boolean isRunning = true;

    public void setIsRunning(boolean bool){
        isRunning = bool;
    }

    public Provider(Distributor distribuidor) {
        super();
        this.distribuidor = distribuidor;
    }

    @Override
    public void run() {
        while (isRunning) {
            try {
                distribuidor.provide((int) (Math.random() * 10) + 1);
                Thread.sleep(1000);
            } catch (Exception e) {
                // TODO: handle exception
            }
        }
        System.out.println("Provider Interrupted");
    }
}

---

在您的Distributor類中，更改以下內容：

private Provider pro = new Provider(this);
private Thread provider = new Thread(pro);

和

btn.addActionListener(new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent e) {
        try {
            pro.setIsRunning(false);
            provider.interrupt();
            provider.join();
            System.out.println(provider.isAlive());

            for (Thread t : retailerList) {
                t.interrupt();
                t.join();
                System.out.println(t.isAlive());
            }
        } catch (InterruptedException e1) {
            e1.printStackTrace();
        }
    }
});

---

單擊停止按鈕后的輸出

Answer 2

不要在循環內捕獲InterruptedException，而應將循環放入try {...}中

提供者類別：

public class Provider implements Runnable {

    private Distributor distribuidor;
    private int total = 0;

    public Provider(Distributor distribuidor) {
        super();
        this.distribuidor = distribuidor;
    }

    @Override
    public void run() {
        try {
            while (!Thread.currentThread().isInterrupted()) {
                distribuidor.provide((int) (Math.random() * 10) + 1);
                Thread.sleep(10);
            }
        } catch (InterruptedException interruptedException) {
        }
        System.out.println("Provider Interrupted");
    }
}

零售商類別：

public class Retailer implements Runnable {

    private Distributor distributor;
    private int total = 0;
    private int id;

    public Retailer(int id, Distributor distributor) {
        super();
        this.id = id;
        this.distributor = distributor;
    }

    @Override
    public void run() {
        try {
            while (!Thread.currentThread().isInterrupted()) {
                total += distributor.sell();
                Thread.sleep(10);
            }
        } catch (InterruptedException interruptedException) {
        }
        System.out.println("Retailer id: " + id + " bought: " + total + " products");
    }
}