明明硬盘中存在users.xml，但是提示：系统找不到指定的路径。

解决办法：

设置String的编码格式

1 realpath = URLDecoder.decode(realpath, "UTF-8");

源代码：

 1 package cn.itcast.utils; 2 ?3 import java.io.File; 4 import java.io.FileOutputStream; 5 import java.io.IOException; 6 import java.io.UnsupportedEncodingException; 7 import java.net.URL; 8 import java.net.URLDecoder; 9 10 import org.dom4j.Document;11 import org.dom4j.DocumentException;12 import org.dom4j.io.OutputFormat;13 import org.dom4j.io.SAXReader;14 import org.dom4j.io.XMLWriter;15 16 public class XmlUtils {17 18 ????private static String filename = "users.xml";19 20 ????public static Document getDocument() throws DocumentException, UnsupportedEncodingException {21 22 ????????URL url = XmlUtils.class.getClassLoader().getResource(filename);23 ????????String realpath = url.getPath();24 25 ????????realpath = URLDecoder.decode(realpath, "UTF-8");26 27 ????????SAXReader reader = new SAXReader();28 ????????return reader.read(new File(realpath));29 ????}30 31 ????public static void write2Xml(Document document) throws IOException {32 33 ????????URL url = XmlUtils.class.getClassLoader().getResource(filename);34 ????????String realpath = url.getPath();35 36 ????????realpath = URLDecoder.decode(realpath, "UTF-8");37 38 ????????OutputFormat format = OutputFormat.createPrettyPrint();39 ????????XMLWriter writer = new XMLWriter(new FileOutputStream(realpath), format);40 ????????writer.write(document);41 ????????writer.close();42 ????}43 }

HTTP Status 500 – Internal Server Error

Type Exception Report

Message org.dom4j.DocumentException: C:\Program%20Files\Apache%20Software%20Foundation\Tomcat%208.5\webapps\day09_user\WEB-INF\classes\users.xml (系统找不到指定的路径。) Nested exception: C:\Program%20Files\Apache%20Software%20Foundation\Tomcat%208.5\webapps\day09_user\WEB-INF\classes\users.xml (系统找不到指定的路径。)

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

java.lang.RuntimeException: org.dom4j.DocumentException: C:\Program%20Files\Apache%20Software%20Foundation\Tomcat%208.5\webapps\day09_user\WEB-INF\classes\users.xml (系统找不到指定的路径。) Nested exception: C:\Program%20Files\Apache%20Software%20Foundation\Tomcat%208.5\webapps\day09_user\WEB-INF\classes\users.xml (系统找不到指定的路径。)cn.itcast.dao.impl.UserDaoXmlImpl.find(UserDaoXmlImpl.java:35)cn.itcast.service.impl.BusinessServiceImpl.loginUser(BusinessServiceImpl.java:29)cn.itcast.web.controller.LoginServlet.doGet(LoginServlet.java:23)cn.itcast.web.controller.LoginServlet.doPost(LoginServlet.java:38)javax.servlet.http.HttpServlet.service(HttpServlet.java:661)javax.servlet.http.HttpServlet.service(HttpServlet.java:742)org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

Root Cause

org.dom4j.DocumentException: C:\Program%20Files\Apache%20Software%20Foundation\Tomcat%208.5\webapps\day09_user\WEB-INF\classes\users.xml (系统找不到指定的路径。) Nested exception: C:\Program%20Files\Apache%20Software%20Foundation\Tomcat%208.5\webapps\day09_user\WEB-INF\classes\users.xml (系统找不到指定的路径。)org.dom4j.io.SAXReader.read(SAXReader.java:266)cn.itcast.utils.XmlUtils.getDocument(XmlUtils.java:28)cn.itcast.dao.impl.UserDaoXmlImpl.find(UserDaoXmlImpl.java:18)cn.itcast.service.impl.BusinessServiceImpl.loginUser(BusinessServiceImpl.java:29)cn.itcast.web.controller.LoginServlet.doGet(LoginServlet.java:23)cn.itcast.web.controller.LoginServlet.doPost(LoginServlet.java:38)javax.servlet.http.HttpServlet.service(HttpServlet.java:661)javax.servlet.http.HttpServlet.service(HttpServlet.java:742)org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

Note The full stack trace of the root cause is available in the server logs.

Apache Tomcat/8.5.24