JOptionPane给出错误

Question

我想用JOptionPanes来处理一些异常。下面是main方法：

public class MainRun {

public static void main(String args[]){    
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                UIManager.setLookAndFeel(new SubstanceRavenGraphiteGlassLookAndFeel());
            }catch (Exception e){
                e.printStackTrace();
            }                 
            new MainGui().setVisible(true);                
            new Initialized().start();
            new PriorityMessageQueue().start();
        }
    });

MainGui是应用程序的主窗口(JFrame)。我处理了PriorityMessageQueue线程内部的异常。

public class PriorityMessageQueue extends Thread {

@Override
public void run() {

    while (true) {
        try {
            instantMessages = instant.getMobitelMessagesToBeSent();
        } catch (Exception ex) {
                        JOptionPane.showMessageDialog(
                        null,
                        ex.getMessage(),
                        "Database Error",
                        JOptionPane.ERROR_MESSAGE);

        }

        ...

运行此命令后，我收到一个错误

   org.jvnet.substance.api.UiThreadingViolationException: Component creation must be done on Event Dispatch Thread
at org.jvnet.substance.utils.SubstanceCoreUtilities.testComponentCreationThreadingViolation(SubstanceCoreUtilities.java:2312)
at org.jvnet.substance.SubstanceOptionPaneUI.createUI(SubstanceOptionPaneUI.java:83)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:37)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:244)
at javax.swing.UIDefaults.getUI(UIDefaults.java:752)
at javax.swing.UIManager.getUI(UIManager.java:989)
at javax.swing.JOptionPane.updateUI(JOptionPane.java:1859)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1822)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1785)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1753)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1731)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1711)
at GUI.MainGui.showOptionPane(MainGui.java:1039)
at SMS.PriorityMessageQueue.run(PriorityMessageQueue.java:86)
    UIDefaults.getUI() failed: createUI() failed for
      javax.swing.JOptionPane
   [,0,0,0x0,invalid,alignmentX=0.0,alignmentY=0.0,border=,flags=0,maximumSize=,minimumSize=,p
   referredSize=,icon=,initialValue=,message=DatabaseConnection class
   connect,messageType=ERROR_MESSAGE,optionType=DEFAULT_OPTION,wantsInput=false]
   java.lang.reflect.InvocationTargetException
   java.lang.Error
at javax.swing.UIDefaults.getUIError(UIDefaults.java:712)
at javax.swing.MultiUIDefaults.getUIError(MultiUIDefaults.java:133)
at javax.swing.UIDefaults.getUI(UIDefaults.java:758)
at javax.swing.UIManager.getUI(UIManager.java:989)
at javax.swing.JOptionPane.updateUI(JOptionPane.java:1859)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1822)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1785)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1753)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1731)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1711)
at GUI.MainGui.showOptionPane(MainGui.java:1039)
at SMS.PriorityMessageQueue.run(PriorityMessageQueue.java:86)

并且JOptionPane将不能正常显示！

​

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如何才能获得parentComponent (MainGui JFrame)，而不是将null传递给JOptionPane？

Answer 1

JOptionPane是一个迷你Swing GUI，和所有Swing GUI一样，它必须在Swing事件线程上创建，而不是在后台线程上创建。这可以通过在Runnable中创建JOptionPane，然后在事件线程上将Runnable排队来完成：

SwingUtilities.invokeLater(new Runnable() {
  public void run() {
    JOptionPane.showMessageDialog(....);
  }
});

例如,

} catch (Exception ex) {
   final String exMessage = ex.getMessage();

   SwingUtilities.invokeLater(new Runnable() {
     public void run() {
       JOptionPane.showMessageDialog(
         null,
         exMessage,
         "Database Error",
         JOptionPane.ERROR_MESSAGE);
       );
     }
   });
  }
}

关于你的问题，

如何才能获得parentComponent (MainGui JFrame)而不是将null传递给JOptionPane？

您需要一个对主GUI的引用。你如何获得它将取决于你的程序是如何组织的。

Answer 2

• Substance非常敏感，所有更新都必须在EDT
• 上完成，否则您只能看到来自RepaintManager的Swing JComponents
• or异常的toolbar (来自Native OS) (我认为来自RepaintManager的Trident package)
• JOptionPane必须包装到invokeLater()中，然后您的JOptionPane才可见，

< code >H118我认为您的exception谈到了另一个问题，您的代码中隐藏了一些东西，可能使用的Substance L&F没有什么问题，这是次要问题