Question

有必要制作自定义控制台。我有以下代码：

public class Console extends OutputStream{

private Console(ResourceBundle resourceBundle) throws IOException {
    FXMLLoader loader = new FXMLLoader(this.getClass().getResource("Console.fxml"), resourceBundle);
    controller = loader.getController();
    Scene scene = new Scene((Parent) loader.load());
    stage = new Stage();
    stage.setScene(scene);
    show();
}

@Override
public void write(int b) throws IOException {
    controller.append(b);
}

public static Console getInstance(ResourceBundle resourceBundle) {
    if (console == null) {
        try {
            console = new Console(resourceBundle);
        } catch (IOException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }
    }
    return console;
}

public void show() {
    stage.show();
}

private static Console console = null;
private ConsoleController controller;
private Stage stage;
}

控制器文件：

public class ConsoleController implements Initializable {

@Override
public void initialize(URL url, ResourceBundle resourceBundle) {
}

@FXML
public void append(int i) {
    textArea.appendText(String.valueOf((char) i));
}

@FXML
private TextArea textArea;
}

所有这些都是从'start（）'调用的：

    @Override
public void start(Stage primaryStage) throws IOException {
    ...
    System.setErr(new PrintStream(Console.getInstance(rb)));
}

在异常期间，textArea的{{1}}中没有打印任何内容，但会抛出以下异常：

线程“JavaFX应用程序线程”中的异常异常：从线程“JavaFX Application Thread”中的UncaughtExceptionHandler抛出java.lang.NullPointerException

我做错了什么？

------的修改 --------

在了解到需要使用多个线程之后，我有以下代码：

Console.fxml

但结果只是：“启动控制台”，没有public class Console{ private Console(ResourceBundle resourceBundle) throws IOException { FXMLLoader loader = new FXMLLoader(this.getClass().getResource("Console.fxml"), resourceBundle); Parent root = (Parent) loader.load(); controller = loader.getController(); Scene scene = new Scene(root); stage = new Stage(); stage.setScene(scene); show(); if (errorOutputThread != null) { errorOutputThread.interrupt(); try { errorOutputThread.join(); } catch (InterruptedException e) { e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates. } errorOutputThread = null; } if (outOutputThread != null) { outOutputThread.interrupt(); try { outOutputThread.join(); } catch (InterruptedException e) { e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates. } outOutputThread = null; } System.err.flush(); System.out.flush(); outPipedInputStream = new PipedInputStream(); outPipedOutputStream = new PipedOutputStream(outPipedInputStream); System.setOut(new PrintStream(outPipedOutputStream)); errorPipedInputStream = new PipedInputStream(); errorPipedOutputStream = new PipedOutputStream(errorPipedInputStream); System.setErr(new PrintStream(errorPipedOutputStream)); outOutputThread = new Thread(new ConsoleStream(outPipedInputStream, "OUT")); outOutputThread.setDaemon(true); outOutputThread.start(); errorOutputThread = new Thread(new ConsoleStream(errorPipedInputStream, "ERROR")); errorOutputThread.setDaemon(true); errorOutputThread.start(); controller.appendText("Start Console"); } public static Console getInstance(ResourceBundle resourceBundle) { if (console == null) { try { console = new Console(resourceBundle); } catch (IOException e) { e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates. } } return console; } public void show() { stage.show(); } private class ConsoleStream implements Runnable { private ConsoleStream(InputStream in, String type) { inputStream = in; this.type = type; } public void run() { try { InputStreamReader is = new InputStreamReader(inputStream); BufferedReader br = new BufferedReader(is); String read = null; read = br.readLine(); while(read != null) { controller.appendText(read + "\n"); read = br.readLine(); } } catch (IOException e) { e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates. } controller.appendText("Thread" + type + "started"); } private final InputStream inputStream; private String type; } private static Console console = null; private ConsoleController controller; private Stage stage; private PrintStream printStream; private PipedOutputStream customPipedOutputStream; private PipedOutputStream errorPipedOutputStream; private PipedOutputStream outPipedOutputStream; private PipedInputStream customPipedInputStream; private PipedInputStream errorPipedInputStream; private PipedInputStream outPipedInputStream; private Thread customOutputThread; private Thread outOutputThread; private Thread errorOutputThread; }的结果，所以看起来这个线程没有启动。但为什么呢？

Answer 1

我认为你必须在获得控制器实例之前加载表单

FXMLLoader loader = new FXMLLoader(this.getClass().getResource("Console.fxml"),resourceBundle);
Parent p = (Parent) loader.load()
controller = loader.getController();
Scene scene = new Scene(p);

如何制作自定义Java / JavaFX控制台？

1 个答案: