关闭应用程序后程序不会停止

Question

我尝试重新创建四子棋，并且成功了。但我想通过时不时地切换颜色来让玩家知道获胜的四张棋子在哪里。我对编程中的线程和时间概念很陌生。

我也成功地向用户提供了此指示，但在关闭应用程序后，控制台仍然给出输出，当我使用 setOnCloseRequest 时也是如此。

其他一些问题：
1：对于我使用 html 名称的颜色，使用十六进制三元组更好还是没有偏好。
2：为了阻止网格和其他元素紧贴屏幕左侧，我添加了一个与背景颜色相同的边框，有更好的方法吗？
3：我没有创建将键码转换为整数的方法，而是在 init 函数中创建。我这样做是因为我不知道如何传递关键事件。这个怎么做？

这是代码：

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class FourInARow extends Application {

GridPane boardGrid = new GridPane();

Label[][] labels = new Label[7][7];
Label statusLabel = new Label();
int[][] cell = new int[7][6];

int player = 0;
int won = 0;

String baseStyle = "-fx-background-radius: 40; -fx-min-width: 80; -fx-min-height: 80; -fx-alignment: center; -fx-border-width: 2; -fx-border-color: #000000;-fx-background-color: ";

ScheduledExecutorService service = Executors.newSingleThreadScheduledExecutor();

public static void main(String[] args){launch(args);}

private void init(Stage window){

    createLabels();
    startGame();

    Label above = new Label("Try to connect four discs in a row!");
    above.setStyle("-fx-font-size: 30; -fx-alignment: center; -fx-min-width: 600");
    boardGrid.setStyle("-fx-background-color: silver;-fx-border-color: #F4F4F4;-fx-border-width: 0 20 0 20");
    Button newGame = new Button("New Game");
    newGame.setStyle("-fx-min-width: 100;-fx-font-size:20");
    newGame.setOnAction(e -> startGame());
    statusLabel.setStyle("-fx-font-size: 30;-fx-alignment: center; -fx-min-width: 300;");
    HBox below = new HBox();
    below.setStyle("-fx-border-width: 0 0 0 20;-fx-border-color: #F4F4F4");
    below.getChildren().addAll(newGame, statusLabel);
    VBox layout = new VBox();
    layout.getChildren().addAll(above, boardGrid, below);
    Scene scene = new Scene(layout, 600, 620);
    scene.setOnKeyPressed(e -> {
        if (won == 0) {
            try {
                String k = e.getCode().toString();
                int l = k.length();
                int col = Integer.parseInt(k.substring(l - 1, l)) - 1;
                placeDisc(col, player);
                switchPlayer();
                updateScreen();
            } catch (NumberFormatException | ArrayIndexOutOfBoundsException error) {
                System.out.println("error: " + error);
            }
        }
    });
    window.setScene(scene);
    window.setTitle("Connect Four");

    threadThing();
}

private void threadThing() {
    service.scheduleAtFixedRate(() -> {
        try {
            wonStyle();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }, 0, 1, TimeUnit.SECONDS);
}

private void startGame() {
    cell = new int[7][6];
    won = player = 0;
    statusLabel.setText("");
    updateScreen();
}

private void updateScreen() {
    for (int i = 0; i < 7; i++) {
        for (int j = 0; j < 6; j++) {
            labels[i][j].setStyle(baseStyle + addStyle(cell[i][j]));
        }
        labels[i][6].setText(Integer.toString(i+1));
        labels[i][6].setStyle("-fx-alignment: center;-fx-min-width: 80;-fx-background-color: #F4F4F4;-fx-font-size: 30;");
    }

    switch(won) {
        case 1: statusLabel.setText("Blue has won!");break;
        case 2: statusLabel.setText("Yellow has won!");break;
    }
}

private String addStyle(int cell) {
    String style = "silver";
    switch(cell){
        case 1: style = "blue"; break;
        case 2: style = "yellow"; break;
        case 3: style = "darkblue"; break;
        case 4: style = "gold;"; break;
    }
    return style;
}

private void placeDisc(int col, int player) {
    for (int i = 5; i >= 0 ; i--) {
        if(cell[col][i] == 0){
            cell[col][i] = 1;
            if(player == 1) cell[col][i] = 2;
            break;
        }else{
            if(i==0) switchPlayer();
        }
    }
    checkWon();
}

private void checkWon() {
    for (int i = 0; i < 7; i++) {
        for (int j = 0; j < 6; j++) {
            if (cell[i][j] != 0) {
                try {
                    if (cell[i][j] == cell[i][j + 1] && cell[i][j] == cell[i][j + 2] && cell[i][j] == cell[i][j + 3]) {
                        won = cell[i][j];
                        cell[i][j] = cell[i][j + 1] = cell[i][j + 2] = cell[i][j + 3] = cell[i][j] + 2;
                    }
                }catch(ArrayIndexOutOfBoundsException error) {}
                try {
                    if (cell[i][j] == cell[i + 1][j] && cell[i][j] == cell[i + 2][j] && cell[i][j] == cell[i + 3][j]) {
                        System.out.println("Horizontal win");
                        won = cell[i][j];
                        cell[i][j] = cell[i + 1][j] = cell[i + 2][j] = cell[i + 3][j] = cell[i][j] + 2;
                    }
                }catch(ArrayIndexOutOfBoundsException error) {}
                try {
                    if (cell[i][j] == cell[i + 1][j + 1] && cell[i][j] == cell[i + 2][j + 2] && cell[i][j] == cell[i + 3][j + 3]) {
                        won = cell[i][j];
                        cell[i][j] = cell[i + 1][j + 1] = cell[i + 2][j + 2] = cell[i + 3][j + 3] = cell[i][j] + 2;
                    }
                }catch(ArrayIndexOutOfBoundsException error) {}
                try {
                    if (cell[i][j] == cell [i + 1][j - 1] && cell[i][j] == cell[i + 2][j - 2] && cell[i][j] == cell[i + 3][j - 3]) {
                        won = cell[i][j];
                        cell[i][j] = cell[i + 1][j - 1] = cell[i + 2][j - 2] = cell[i + 3][j - 3] = cell[i][j] + 2;
                    }
                }catch(ArrayIndexOutOfBoundsException error) {}
            }
        }
    }
}

private void switchPlayer() {
    if(player == 0) player = 2;
    player--;
}

private void createLabels() {
    for (int i = 0; i < 7; i++) {
        for (int j = 0; j < 7; j++) {
            labels[i][j] = new Label();
            boardGrid.add(labels[i][j], i, j);
        }
    }
}

private void wonStyle() throws InterruptedException {
    System.out.println("Test");
    boolean run = false;
    for (int i = 0; i < 7; i++) {
        for (int j = 0; j < 6; j++) {
            if(cell[i][j] > 2 && !run){
                Thread.sleep(500);
                addStyleFlicker();
                run = true;
            }
        }
    }
}

private void addStyleFlicker() throws InterruptedException {
    String[] styleOne = {"-fx-background-radius: 40; -fx-min-width: 80; -fx-min-height: 80; -fx-alignment: center; -fx-border-width: 2; -fx-border-color: #000000;-fx-background-color: blue;",
                         "-fx-background-radius: 40; -fx-min-width: 80; -fx-min-height: 80; -fx-alignment: center; -fx-border-width: 2; -fx-border-color: #000000;-fx-background-color: darkblue;"};
    String[] styleTwo = {"-fx-background-radius: 40; -fx-min-width: 80; -fx-min-height: 80; -fx-alignment: center; -fx-border-width: 2; -fx-border-color: #000000;-fx-background-color: yellow;",
                         "-fx-background-radius: 40; -fx-min-width: 80; -fx-min-height: 80; -fx-alignment: center; -fx-border-width: 2; -fx-border-color: #000000;-fx-background-color: gold;"};
    for (int i = 0; i < 7; i++) {
        for (int j = 0; j < 6; j++) {
            if(cell[i][j] == 3){
                labels[i][j].setStyle(styleOne[0]);
            }else if(cell[i][j] == 4){
                labels[i][j].setStyle(styleTwo[0]);
            }
        }
    }
    Thread.sleep(500);
    for (int i = 0; i < 7; i++) {
        for (int j = 0; j < 6; j++) {
            if(cell[i][j] == 3){
                labels[i][j].setStyle(styleOne[1]);
            }else if(cell[i][j] == 4) {
                labels[i][j].setStyle(styleTwo[1]);
            }
        }
    }
}

@Override
public void start(Stage window) throws Exception {
    init(window);
    window.show();
}
}

Answer 1

根据 Thread 类的 Java API 文档...

Java 虚拟机继续执行线程，直到发生以下任一情况：

• Runtime 类的 exit 方法已被调用，并且安全管理器已允许进行退出操作。
• 所有非守护线程的线程都已死亡，原因是从对 run 方法的调用返回或抛出传播到 run 方法之外的异常。

因此，您需要 Executor 创建 Daemon 线程，当 JVM 准备退出时，该线程将终止。您可以使用自定义线程工厂来完成此操作。这是一个非常简单的例子：

Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {
        
        @Override
        public Thread newThread(Runnable r) {
            Thread t = new Thread(r);
            t.setDaemon(true);
            return t;
        }
    });