使用JScience解析mathml文檔

Question

我試圖使用JScience解析mathml文檔，但沒有成功。以下是我的一段代碼。

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(); 
} 
} 

我從這裏得到了錯誤，所以我什麼都做不了。以下是堆棧跟蹤：

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 

而且，沒有任何一個有任何想法如何使用MathMLApplyElementImpl，MathMLDocumentImpl或JSci.mathml包中的任何其他類？

如果您可以提供一些關於如何解析mathml文檔的代碼示例，那將會很棒。

任何想法將不勝感激。 謝謝

Answer 1

共同確定你的確切的bug，看起來類JSci.maths.fields.Ring$Member不存在，它會拋出方法JSci.io.MathMLParser.translateToJSciObjects中的ClassNotFoundException。

讓我們來看看這個源代碼。 在MathMLParser中，最顯着的用法是Ring.Member作爲返回值。但它可以在很多地方找到。 而且，由於Ring.Member在JSci.maths.fields中，它似乎與MathMLParser在相同的JAR中，所以我猜你的問題比簡單的ClassNotFoundException複雜得多。

首先，您可以打開JScience jar以確保JSci.maths.fields.Ring$Member確實存在嗎？

如果不是這種情況，您是否在同一個應用程序中使用多個類加載器？ （像OSGi的東西）