package com.xml;import java.io.File;import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.io.SAXReader;public class Dom4JReaderUtils {? private static final String RESOURCE;? static{ ? ?RESOURCE=Dom4JReaderUtils.class.getClassLoader().getResource("peopleList.xml").getPath();? }? public static Document getDocument(){ Document document=null; SAXReader reader=new SAXReader(); try{ document=reader.read(new File(RESOURCE)); }catch(DocumentException e){ e.printStackTrace(); } return document; ?? }}錯誤原因是RESOURCE=Dom4JReaderUtils.class.getClassLoader().getResource("peopleList.xml").getPath();Caused by: java.lang.NullPointerException