使用WordNet时发生ExceptionInInitializerError

Question

我最近决定下载JWNL，将其用于WordNet的Java接口。 遵循各种教程（例如http://jwordnet.sourceforge.net/handbook.html ），我下载了WordNet（2.1），然后下载了JWNL，将file_properties.xml中的dictionary_path行设置为WordNet的路径。

<param name="dictionary_path" value="c:/res/wordnet/2.1/dict"/>

我将所有的jar添加到我的类路径中，并在Eclipse中创建了以下简单的类进行测试：

    public static void main(String[] args) throws FileNotFoundException, 
                                             JWNLException {
          JWNL.initialize(new FileInputStream("C:\\path\\file_properties.xml"));
          Dictionary wordnet = Dictionary.getInstance();

          IndexWord word = wordnet.getIndexWord(POS.NOUN, "monarch");
          for(Synset syn : word.getSenses()) {
               System.out.println(syn.getGloss());
          }
    }

在Eclipse中运行会产生以下错误：

Exception in thread "main" java.lang.ExceptionInInitializerError
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at net.didion.jwnl.util.factory.Element.install(Element.java:31)
at net.didion.jwnl.JWNL.initialize(JWNL.java:169)
at TestingOnWordNet.main(TestingOnWordNet.java:28)

Caused by: org.apache.commons.logging.LogConfigurationException: org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException) (Caused by org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException))
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:543)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:235)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:209)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:351)
at net.didion.jwnl.util.MessageLog.<init>(MessageLog.java:11)
at net.didion.jwnl.dictionary.Dictionary.<clinit>(Dictionary.java:24)
... 5 more

Caused by: org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException)
at org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:397)
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:529)
... 10 more

Caused by: java.lang.NullPointerException
at org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:374)
... 11 more

有什么我想念的吗？ 我正准备考虑使用JAWS之类的替代产品，但我希望可能有一种解决此问题的方法。

谢谢！

Answer 1

您没有将jar添加到classpath。 将lib / commons-logging.jar添加到类路径。