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我试图使用 JScience 解析 mathml 文档，但没有成功。以下是我的一段代码。

import JSci.io.*;
import JSci.mathml.*;
  .
  .
public class ParsingMathML(){
 try {
        ....
        //inputFile is an xml file containing mathml code
 InputSource file = new InputSource(new FileReader(inputFile));  
 MathMLParser parser = new MathMLParser();
 parser.parse(file);

 Object[] parseList = parser.translateToJSciObjects();
}catch (Exception e) {
 e.printStackTrace();
}
}

我从这里得到错误，所以我无法做任何进一步的事情。以下是 StackTrace：

Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: JSci/maths/fields/Ring$Member
 at JSci.io.MathMLParser.translateToJSciObjects(Unknown Source)
 at JSci.io.MathMLParser.translateToJSciObjects(Unknown Source)
 at mathML.ProcessMathML.processFile(ParsingMathML.java:109)
 at mathML.ProcessMathML.actionPerformed(ParsingMathML.java:72)
 at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
 at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
 at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
 at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
 at javax.swing.AbstractButton.doClick(Unknown Source)
 at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
 at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(Unknown Source)
 at java.awt.Component.processMouseEvent(Unknown Source)
 at javax.swing.JComponent.processMouseEvent(Unknown Source)
 at java.awt.Component.processEvent(Unknown Source)
 at java.awt.Container.processEvent(Unknown Source)
 at java.awt.Component.dispatchEventImpl(Unknown Source)
 at java.awt.Container.dispatchEventImpl(Unknown Source)
 at java.awt.Component.dispatchEvent(Unknown Source)
 at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
 at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
 at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
 at java.awt.Container.dispatchEventImpl(Unknown Source)
 at java.awt.Window.dispatchEventImpl(Unknown Source)
 at java.awt.Component.dispatchEvent(Unknown Source)
 at java.awt.EventQueue.dispatchEvent(Unknown Source)
 at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
 at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
 at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
 at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
 at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
 at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: JSci.maths.fields.Ring$Member
 at java.net.URLClassLoader$1.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at java.lang.ClassLoader.loadClassInternal(Unknown Source)
 ... 31 more

另外，是否有人知道如何使用 MathMLApplyElementImpl、MathMLDocumentImpl 或 JSci.mathml 包中的任何其他类？

如果您能提供一些关于如何解析 mathml 文档的代码示例，那就太好了。

任何想法都将受到高度赞赏。谢谢

4

1 回答 1

2

考虑到您的确切错误，似乎该类JSci.maths.fields.Ring$Member不存在，这会在方法中引发 ClassNotFoundException JSci.io.MathMLParser.translateToJSciObjects。

让我们看看这个源代码。在 MathMLParser 中，最显着的用法Ring.Member是作为返回值。但它可以在许多地方找到。而且，由于 Ring.Member 在 中JSci.maths.fields，它似乎与 MathMLParser 在同一个 JAR 中，我猜你的问题比简单的 ClassNotFoundException 复杂得多。

首先，您可以打开 JScience jar 以确保JSci.maths.fields.Ring$Member确实存在吗？

如果不是这样，您是否在同一个应用程序中使用多个类加载器？（像 OSGi 之类的东西）

于 2010-07-06T09:36:00.460 回答