编辑2：
好的，我希望这是您的操作方式。以下是我使用的类的精简版本。如果我在SurfaceObject（）类中包含所有的Getter和Setter，则错误仍然存在，但如果排除它们，该错误似乎消失了。这很奇怪。甚至很奇怪的是，如果所有变量都是私有变量，而不是像示例中那样受保护，它似乎也会出现。所以我想知道为什么会这样：
主类（构建JFrame）：
import javax.swing.JFrame;
public class FileCreator extends JFrame{
private static FileCreator chooseAction;
private Container contain;
public static final int framewidth = 800;
public static final int frameheight = 600;
private final String[] iconName = {"Load File"};
public static void main(String[] args) {
chooseAction = new FileCreator();
}
public FileCreator(){
super("Editor");
contain = new Container(iconName, this);
add(contain);
setSize(framewidth,frameheight);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
}
此类会构建容器并将卡片添加到其中（第一张卡片为holdContent，
第二张卡是FirstOptionPanel）。它还添加了ActionListener MainListener，
依次调用createPanel（）-Method
import java.awt.CardLayout;
import java.io.File;
import javax.swing.JButton;
import javax.swing.JPanel;
class Container extends JPanel {
private FirstOptionPanel[] panels = new FirstOptionPanel[9];
private final String[] cardNames = { "card1", "File Loaded" };
private JButton[] buttons;
private MainMenuListener main;
private int contentWidth = 410, contentHeight = 300;
private CardLayout cards;
Container(String[] buttonName,
FileCreator creator) {
super();
setLayout(cards = new CardLayout());
setSize(FileCreator.framewidth, FileCreator.frameheight);
buttons = new JButton[buttonName.length];
int i = 0;
buttons[i] = new JButton(buttonName[i]);
main = new MainMenuListener(this, creator);
buttons[i].addActionListener(main);
JPanel card1 = new JPanel();
card1.setSize(getWidth(), getHeight());
card1.setLayout(null);
JPanel holdContent = new JPanel();
holdContent.setSize(contentWidth, contentHeight);
holdContent.setLocation((FileCreator.framewidth - contentWidth) / 2,
(FileCreator.frameheight - contentHeight) / 2);
holdContent.add(buttons[i]);
card1.add(holdContent);
add(card1, cardNames[0]);
}
public JButton[] getButtons() {
return buttons;
}
public void createPanel(int i, File selectedFile) {
panels[i] = new FirstOptionPanel(selectedFile);
add(panels[i], cardNames[i + 1]);
cards.show(this, cardNames[i + 1]);
}
}
此类是ActionListener。它只是记录按下的按钮
并在按下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，它将加载文件并传递它。
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!");
}
}
}
}
}
这是FirstOptionPanel类。这是一个JPanel，它创建其他JPanel（在本例中为单个entry-Object），然后显示它们：
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]);
}
}
最后是SurfaceObject类。前面提到的SurfaceEntry-Class扩展了该类。这里不使用SurfaceEntry（），但仍会发生错误。但是只有当我拥有所有这些不同的getters（）和setters（）时。如果我不包括它们，则程序运行正常。即使我实际上还没有使用它们（前面的大文件）：
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;
}
}
这是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)
我希望这足以说明问题。提前致谢，
尼古拉
最佳答案
找到了我问题的答案。对于任何想知道的人，似乎Java都对我的SurfaceObject（）类的方法“ public FirstOptionPanel getParent（）”有问题。我用一个超类的方法向我自己解释这一点。哪种原因导致无法在另一个线程中创建？如果有人有一个更可能的答案，我倾向于倾听。 （Eclipse只是生成了这样的get-method，我自己不会那样做。如果我更改方法名称，则程序可以正常运行）