在javax.swing应用程序中捕获异常 [英] Catch exceptions in javax.swing application

问题描述

我正在使用 javax.swing 来创建一个从XML Schema生成表单的应用程序（使用JAXFront库），并将用户填写的数据存储到XML中文件。

当我需要它时，我已经放入try-catch-finally块，但主线程结束时捕获异常有一些问题（AWT线程仍然存在运行）。

我有两个课程，主要工作和其他类不重要的问题：

• 主类 ：它具有以下结构。初始化应用程序并运行主框架

    public class Main {
   public static void main（String [] args） {
   readArgs（）; //具有app config INI文件
  模型model = initializeElements（args）; //我的模型类
   try {
   MyFrame mfr = new MyFrame（title，model）; 
   mfr.visualize（）; //组装视图和设置可见
  } catch（Excepion e）{
   doCleanUp（）; 
   System.exit（-1）; 
  } 
  } 
  }  




• Class ：生成视图和听事件

    public class MyFrame extends JFrame implements ActionListener，MenuListener { 
   //某些属性
   //其他没有重要性的主体
   / ** 
   *组成元素，添加听众并设置可见的框架
   * / 
   public void visualize（）{
   generateFormPanel（）; 
   setListeners（）; 
   validate（）; 
   setVisible（true）; 
  } 
   
   public MyFrame（String title，Modele model）{
   super（title）; 
   createElementsUsing（model）; 
  } 
   
   public void actionPerformed（ActionEvent e）{
   //管理事件的代码
  } 
  }  pre> 

嗯，问题是如下：
当从main方法，视图生成和显示。那时候我失去了捕捉异常的控制。那么我的问题是，如果有一些方法可以捕获在这一点之后抛出的可能的RuntimeExceptions 。

我希望你了解我的英语，并且可以回答

提前感谢。

解决方案

最简单的版本是设置默认未捕获的异常处理程序：

  Thread.setDefaultUncaughtExceptionHandler（new Thread.UncaughtExceptionHandler（）{
 public void uncaughtException （Thread t，Throwable e）{
 // do something 
} 
}）; 
  

但是，在程序的其他部分抛出未捕获的异常。

然而，您可以仅使用代理程序捕获swing事件调度线程抛出的运行时异常（请参阅此页面了解更多信息，复制代码）：

  class EventQueueProxy extends EventQueue {
 
 protected void dispatchEvent（AWTEvent newEvent）{
 try {
 super.dispatchEvent（newEvent ）; 
} catch（Throwable t）{
 //做一些比t.printStackTrace（）更有用的东西; 
} 
} 
} 
  

现在安装如下：

  Toolkit.getDefaultToolkit（）。getSystemEventQueue（）。push（new EventQueueProxy（））; 
  

I'm working with javax.swing to make an aplication which generates forms from XML Schema (using JAXFront library) and stores the data filled by the user them into XML documents.

I have put try-catch-finally blocks when I need it, but I have a little problem catching exceptions when the main thread ends (The AWT threads are still running).

I have two classes which do the main work and other classes which aren't important for the question:

• Main class: It has the following structure. Initializes the application and runs the main frame

  public class Main { 
      public static void main(String[] args) {
          readArgs(); // An INI file with the app config
          Model model = initializeElements(args); // My model class
          try {
              MyFrame mfr = new MyFrame(title,model);
              mfr.visualize(); // Assembling view and setting visible
          } catch( Excepion e ) {
              doCleanUp();
              System.exit(-1);
          }
      }
  }

• Frame Class: Generates the view and listen events

  public class MyFrame extends JFrame implements ActionListener,MenuListener { 
      // Some attributes
      // Other mthods without importance
      /**
       * Compose the elements, add listeners and set visible the frame
       */
      public void visualize() {
          generateFormPanel();
          setListeners();
          validate();
          setVisible(true);
      }
  
      public MyFrame(String title, Modele model) {
          super(title);
          createElementsUsing(model);
      }
  
      public void actionPerformed(ActionEvent e) {
          // Code to manage events
      }
  }

Well, the problem is the following: When the visualize function is exectuted from the main method, the view is generated and showed. At that moment is when I lose the control of the exceptions catching. Then my question is if there are some way to catch the possible RuntimeExceptions throwed after this point.

I hope you understand my English and can answer the question.

Thanks in advance.

解决方案

Simplest version is to set the default uncaught exception handler:

Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
    public void uncaughtException(Thread t, Throwable e) {
        // do something
    }
});

But that catches uncaught exceptions thrown in other parts of the program aswell.

You could however catch only runtime exceptions thrown off the swing event dispatching thread using a proxy (See this page for more information, copied code from there):

class EventQueueProxy extends EventQueue {

    protected void dispatchEvent(AWTEvent newEvent) {
        try {
            super.dispatchEvent(newEvent);
        } catch (Throwable t) {
            // do something more useful than: t.printStackTrace();
        }
    }
}

Now installing it like this:

Toolkit.getDefaultToolkit().getSystemEventQueue().push(new EventQueueProxy());

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