HTTP Status 500 – Internal Server Error

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

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

源代码：

package cn.itcast.utils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLDecoder;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class XmlUtils {

    private static String filename = "users.xml";

    public static Document getDocument() throws DocumentException, UnsupportedEncodingException {

        URL url = XmlUtils.class.getClassLoader().getResource(filename);
        String realpath = url.getPath();

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

        SAXReader reader = new SAXReader();
        return reader.read(new File(realpath));
    }

    public static void write2Xml(Document document) throws IOException {

        URL url = XmlUtils.class.getClassLoader().getResource(filename);
        String realpath = url.getPath();

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

        OutputFormat format = OutputFormat.createPrettyPrint();
        XMLWriter writer = new XMLWriter(new FileOutputStream(realpath), format);
        writer.write(document);
        writer.close();
    }
}

HTTP Status 500 – Internal Server Error

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Type Exception Report

Message org.dom4j.DocumentException: C:Program%20FilesApache%20Software%20FoundationTomcat%208.5webappsday09_userWEB-INFclassesusers.xml (系统找不到指定的路径。) Nested exception: C:Program%20FilesApache%20Software%20FoundationTomcat%208.5webappsday09_userWEB-INFclassesusers.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%20FilesApache%20Software%20FoundationTomcat%208.5webappsday09_userWEB-INFclassesusers.xml (系统找不到指定的路径。) Nested exception: C:Program%20FilesApache%20Software%20FoundationTomcat%208.5webappsday09_userWEB-INFclassesusers.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%20FilesApache%20Software%20FoundationTomcat%208.5webappsday09_userWEB-INFclassesusers.xml (系统找不到指定的路径。) Nested exception: C:Program%20FilesApache%20Software%20FoundationTomcat%208.5webappsday09_userWEB-INFclassesusers.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.

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Apache Tomcat/8.5.24