Construtor中的调用目标异常 - JavaFx

Question

我正在构建一个javafx项目，我面临下面列出的一些问题。

首先，当我没有在构造函数sfc = new ServerFrameController();＆amp;中初始化2个类时，我得到了NullPointerException。 sf = new ServerFrame();。即使在搜索了几个小时后，我也无法找出空指针异常的原因。然后我想也许初始化类可能会有所帮助。但在添加这两行后，我得到了InvocationTargetException。请帮忙！！

例外：

Exception in Application constructor
java.lang.reflect.InvocationTargetException  
Caused by: java.lang.StackOverflowError  
    at com.socket.ServerFrameController.<init>(ServerFrameController.java:35)  
    at com.socket.ServerFrame.<init>(ServerFrame.java:28)  

第1课：

public class ServerFrame extends Application {

    public ServerFrameController sfc;
    public SocketServer server;
    public Thread serverThread;
    public String filePath = "D:\\Data.xml";
    public JFileChooser fileChooser;
    public JFXPanel fxPanel;

    public ServerFrame() {
        sfc = new ServerFrameController();
        fxPanel = new JFXPanel();
        fxPanel.setVisible(true);
        fileChooser = new JFileChooser();
    }
    // Some More Code.....
}

第2课：

public class ServerFrameController implements Initializable {

    ServerFrame sf;
    @FXML
    public TextField jTextField3;
    @FXML
    public Button jButton2;
    @FXML
    public Button jButton1;
    @FXML
    public TextArea jTextArea1;

    public ServerFrameController() {
        sf = new ServerFrame();
    }
}

Answer 1

您可以通过将StackOverflowError的引用传递给控制器​​来避免ServerFrame的问题，但一般来说，从构造函数中传递this的引用是不好的做法。

public class ServerFrameController implements Initializable {

    ServerFrame sf;
    @FXML
    public TextField jTextField3;
    @FXML
    public Button jButton2;
    @FXML
    public Button jButton1;
    @FXML
    public TextArea jTextArea1;

    public ServerFrameController(ServerFrame sf) {
        this.sf = sf;
    }
}
public class ServerFrame extends Application {

    public ServerFrameController sfc;
    public SocketServer server;
    public Thread serverThread;
    public String filePath = "D:\\Data.xml";
    public JFileChooser fileChooser;
    public JFXPanel fxPanel;

    public ServerFrame() {
        sfc = new ServerFrameController(this);
        fxPanel = new JFXPanel();
        fxPanel.setVisible(true);
        fileChooser = new JFileChooser();
    }
    // Some More Code.....
}

最好的可能是找出NullPointerException并找到适当的解决方案。我猜这是以某种方式与所有初始化的顺序相关。