“线程中的异常”；AWT-EventQueue-0“；java.lang.ClassCastException:添加（）的异常

编辑2： 好的，我希望你就是这样做的。下面是我使用的类的精简版本。如果在SurfaceObject（）类中有所有的getter和setter，那么错误仍然存在，但是如果排除它们，错误似乎会消失。这很奇怪。更奇怪的是，如果变量都是私有的，而不像示例中那样是受保护的，那么它似乎也会出现。所以我想知道为什么会这样： 主类（构建JFrame）：

此类构建容器并将卡添加到其中（第一张卡是holdContent， 第二张卡是第一个选项面板）。它还添加了ActionListener MainListener， 然后调用createPanel（）-方法

这个类是ActionListener。它只记录按下的按钮 并在按load File时调用createPanel（）-方法。但是，JFileChooser 在此版本中不执行任何操作。通常，它加载并传递文件

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class MainMenuListener implements ActionListener {
    private JButton[] buttons;
    private JPanel[] panellist;
    private Container container;
    private JFileChooser jf;
    private FileCreator creator;
    public MainMenuListener(Container container, FileCreator creator) {
        // TODO Auto-generated constructor stub
        buttons= container.getButtons();
        this.creator = creator;
        panellist = container.getPanels();
        this.container = container;
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        for(int i = 0; i<buttons.length;i++){if(i == 0){
                jf = new JFileChooser();
                int returnValue = jf.showOpenDialog(container);     
                if(returnValue == JFileChooser.APPROVE_OPTION){
                    container.createPanel(i, jf.getSelectedFile());
                }else       if(returnValue == JFileChooser.CANCEL_OPTION){
                    JOptionPane.showMessageDialog(creator, "No File selected!");
                }

            }
        }
    }
    }

最后是SurfaceObject类。前面提到的SurfaceEntry类扩展了这个类。此处未使用SurfaceEntry（），但仍会发生错误。但前提是我有所有这些不同的getter（）和setter（）。如果我不包括它们，程序运行得很好。即使我还没有真正使用它们！（前面是大文件）：

这是我运行程序时收到的错误消息：

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException
at javax.swing.LayoutComparator.compare(Unknown Source)
at javax.swing.LayoutComparator.compare(Unknown Source)
at java.util.TimSort.countRunAndMakeAscending(Unknown Source)
at java.util.TimSort.sort(Unknown Source)
at java.util.TimSort.sort(Unknown Source)
at java.util.Arrays.sort(Unknown Source)
at java.util.Collections.sort(Unknown Source)
at javax.swing.SortingFocusTraversalPolicy.enumerateAndSortCycle(Unknown Source)
at javax.swing.SortingFocusTraversalPolicy.getFocusTraversalCycle(Unknown Source)
at javax.swing.SortingFocusTraversalPolicy.getFirstComponent(Unknown Source)
at javax.swing.LayoutFocusTraversalPolicy.getFirstComponent(Unknown Source)
at javax.swing.SortingFocusTraversalPolicy.getDefaultComponent(Unknown Source)
at java.awt.FocusTraversalPolicy.getInitialComponent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.SequencedEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

我希望这是一个足够的解释。提前感谢,

---

尼科莱找到了我问题的答案。对于任何想知道的人来说，似乎Java对我的SurfaceObject（）类的方法“public FirstOptionPanel getParent（）”有问题。我向自己解释这一点的理由是，这是一个来自超类的方法。这使得它不可能在另一个线程中创建？如果有人有更可能的答案，我倾向于听。（Eclipse刚刚生成了那样的get方法，我自己不会这样做。如果我更改了方法名称，程序运行得很好）

猜测：您是否在JFrame上使用CardLayout，然后向同一JFrame添加组件。如果是这样，请理解您实际上是在将版面添加到JFrame的contentPane，而不是JFrame本身，然后您不希望在CardLayout的方法中使用

this

，而是

getContentPane（）

。如果这没有帮助，请创建并发布一个。遗憾的是，事实并非如此。所有的“卡片”都被添加到容器中，而容器被添加到JFrame中。JFrame仅用于显示内容。为什么我不能用“这个”？这代表什么？但没关系。相反，您将希望创建并发布您的I think。在本例中，这表示容器。我会的，如果我能重现错误的话。我还是不太确定。。。如果我有时间，请允许我进一步调查此事。至少可以说很有趣。是的，你是对的。您正在重写super的

getParent（）

，并且您正在更改返回类型，该返回类型不是犹太式的。如果我是你，我也会更改容器类的名称，以免名称冲突。谢谢你的回答。啊，好的，谢谢你提供的信息。现在我确切地知道了为什么它没有像我预期的那样起作用。你完全正确，我不应该给它命名为容器。。。我也要改变这一点。再次感谢您帮助我们更好地了解和理解本网站的政策，当然也为问题提供了解释：）不客气。你的问题是一个反对继承和创作的论点。在继承大型复杂类时，总是存在意外方法重写的危险，这可能导致有害的难以检测的错误。在过去，我通过提供一个JPanel扩展类

getX（）

和

getY（）

方法遇到了这个问题。另一方面，您希望避免使用空布局。通过给容器一个GridBagLayout，然后以默认方式将组件添加到容器中，而不受GridBagLayout的约束，您可以轻松地将一个组件放在另一个组件的中心位置？听起来很有用。。。到目前为止，我尝试过的所有其他布局类型对我的口味来说都太过拘束（我看着你，FlowLayout）。一旦我实现了基本功能，我将明确地看一看它。。。现在，让编辑器工作具有更高的优先级。

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class MainMenuListener implements ActionListener {
    private JButton[] buttons;
    private JPanel[] panellist;
    private Container container;
    private JFileChooser jf;
    private FileCreator creator;
    public MainMenuListener(Container container, FileCreator creator) {
        // TODO Auto-generated constructor stub
        buttons= container.getButtons();
        this.creator = creator;
        panellist = container.getPanels();
        this.container = container;
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        for(int i = 0; i<buttons.length;i++){if(i == 0){
                jf = new JFileChooser();
                int returnValue = jf.showOpenDialog(container);     
                if(returnValue == JFileChooser.APPROVE_OPTION){
                    container.createPanel(i, jf.getSelectedFile());
                }else       if(returnValue == JFileChooser.CANCEL_OPTION){
                    JOptionPane.showMessageDialog(creator, "No File selected!");
                }

            }
        }
    }
    }

import java.io.File;
import javax.swing.JPanel;

public class FirstOptionPanel extends JPanel{
    private SurfaceObject[] entries;
    JPanel buttonHolder;
    public FirstOptionPanel(File selectedFile) {
        // TODO Auto-generated constructor stub
        super();
        setSize(FileCreator.framewidth, FileCreator.frameheight);
        setLayout(null);
        createObjects();
            }
    public FirstOptionPanel() {
        // TODO Auto-generated constructor stub
        super();
    }
    private void createObjects() {
                entries = new SurfaceObject[1];
                    entries[0] = new SurfaceObject("ENTRIES{|,Logo1,,1,,100,,100,,100,,100,|}");
                    add(entries[0]);
                }

}

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MouseInfo;
import javax.swing.ImageIcon;
import javax.swing.JPanel;

public class SurfaceObject extends JPanel{
    /**
     * 
     */
    private String iconName;
    private int id;
    int coordinates[] = new int[2];
    int momentaryCoord[] = new int[2];
    protected boolean imageNotFound;
    protected int[] sizeOfRectangle = new int[2];
    protected String pictureName;
    protected ImageIcon momentaryPicture;
    protected Image img;
    protected boolean mouseInAction;
    protected Dimension d;
    protected boolean selected;
    private FirstOptionPanel parent;
    public SurfaceObject(String group) {
        super();
    }

    @Override
    protected void paintComponent(Graphics g) {
        // TODO Auto-generated method stub
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;
        if (!imageNotFound) {
            g2.drawImage(img, 0, 0, null);
            System.out.println("shown");
        } else {
            System.out.println("Drawn");
            g2.setColor(Color.blue);
            g2.fillRect(0, 0, 200, 200);
        }

    }

    public boolean isSelected() {
        return selected;
    }

    public void setSelected(boolean selected) {
        this.selected = selected;
    }

    public final String getIconName() {
        return iconName;
    }

    public final void setIconName(String iconName) {
        this.iconName = iconName;
    }

    public final int getId() {
        return id;
    }

    public final void setId(int id) {
        this.id = id;
    }

    public final int[] getCoordinates() {
        return coordinates;
    }

    public final void setCoordinates(int[] coordinates) {
        this.coordinates = coordinates;
    }

    public final int[] getMomentaryCoord() {
        return momentaryCoord;
    }

    public final void setMomentaryCoord(int[] momentaryCoord) {
        this.momentaryCoord = momentaryCoord;
    }

    public final boolean isImageNotFound() {
        return imageNotFound;
    }

    public final void setImageNotFound(boolean imageNotFound) {
        this.imageNotFound = imageNotFound;
    }

    public final int[] getSizeOfRectangle() {
        return sizeOfRectangle;
    }

    public final void setSizeOfRectangle(int[] sizeOfRectangle) {
        this.sizeOfRectangle = sizeOfRectangle;
    }

    public final String getPictureName() {
        return pictureName;
    }

    public final void setPictureName(String pictureName) {
        this.pictureName = pictureName;
    }

    public final ImageIcon getMomentaryPicture() {
        return momentaryPicture;
    }

    public final void setMomentaryPicture(ImageIcon momentaryPicture) {
        this.momentaryPicture = momentaryPicture;
    }

    public final Image getImg() {
        return img;
    }

    public final void setImg(Image img) {
        this.img = img;
    }

    public final Dimension getD() {
        return d;
    }

    public final void setD(Dimension d) {
        this.d = d;
    }

    public final boolean isMouseInAction() {
        return mouseInAction;
    }

    public final FirstOptionPanel getParent() {
        return parent;
    }

}

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException
at javax.swing.LayoutComparator.compare(Unknown Source)
at javax.swing.LayoutComparator.compare(Unknown Source)
at java.util.TimSort.countRunAndMakeAscending(Unknown Source)
at java.util.TimSort.sort(Unknown Source)
at java.util.TimSort.sort(Unknown Source)
at java.util.Arrays.sort(Unknown Source)
at java.util.Collections.sort(Unknown Source)
at javax.swing.SortingFocusTraversalPolicy.enumerateAndSortCycle(Unknown Source)
at javax.swing.SortingFocusTraversalPolicy.getFocusTraversalCycle(Unknown Source)
at javax.swing.SortingFocusTraversalPolicy.getFirstComponent(Unknown Source)
at javax.swing.LayoutFocusTraversalPolicy.getFirstComponent(Unknown Source)
at javax.swing.SortingFocusTraversalPolicy.getDefaultComponent(Unknown Source)
at java.awt.FocusTraversalPolicy.getInitialComponent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.SequencedEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)