访问从 sevrlet 转发的 JSP 文件（在 scriptlet 内）中的数据时出现异常
Exception while accessing data in JSP file (within scriptlet) forwarded from sevrlet
我正在尝试访问从 Servlet 发送的 JSP 文件数据。
每当我 运行 项目时，我都会收到异常。
我已经尝试使用
- <% … %>
- ${…}
- <c:out value="${loginFailed}"/>
即使我尝试使用评论标签，也会出现异常。
我一无所知，欢迎任何帮助。
我的一些reading/research
https://whosebug.com/tags/el/info
https://www.tutorialspoint.com/jsp/jsp_actions.htm
How to avoid Java code in JSP files?
...
login.jsp
<?xml version="1.0" encoding="UTF-8" ?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.0">
<jsp:directive.page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" />
<jsp:text> <![CDATA[ <?xml version="1.0" encoding="UTF-8" ?> ]]> </jsp:text>
<jsp:text> <![CDATA[ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> ]]> </jsp:text>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<link rel="stylesheet" type="text/css" href="${pageContext.request.contextPath}/styles/login/css/style.css" />
<title>Connexion</title>
</head>
<body>
<form class="sign-up" method="Post" action="/TP1MiniProjetBanque/home">
<h1 class="sign-up-title">Connexion</h1>
<input type="text" name="mail" class="sign-up-input" placeholder="Mail"/>
<input type="password" name="mdp" class="sign-up-input" placeholder="Mot de passe"/>
<input type="submit" value="Entrer" class="sign-up-button"/>
</form>
<% out.println((String)request.getAttribute("loginFailed")); %>
</body>
</html>
</jsp:root>
JRServlet.java
protected void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.getWriter().append("Served at :").append(request.getContextPath());
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
protected void doPost (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String mail = request.getParameter("mail");
String mdp = request.getParameter("mdp");
if (mail.isEmpty() || mdp.isEmpty() || /**/) {
request.setAttribute("loginFailed", true);
request.getRequestDispatcher("/login.jsp").forward(request, response);
return;
} else {
Client user = new Client(mail, mdp);
request.getRequestDispatcher("/home.jsp").forward(request, response);
return;
}
//doGet(request, response);
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>TP1MiniProjetBanque</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>home</servlet-name>
<servlet-class>jrservlet.JRServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>home</servlet-name>
<url-pattern>/home</url-pattern>
</servlet-mapping>
</web-app>
层次结构
workspace/TP1MiniProjetBanque/
├── build
│ └── classes
│ └── jrservlet
│ ├── Client.class
│ ├── Compte.class
│ ├── DB.class
│ ├── JRServlet.class
│ └── testing.class
├── src
│ └── jrservlet
│ ├── Client.java
│ ├── Compte.java
│ ├── DB.java
│ ├── JRServlet.java
│ └── testing.java
└── WebContent
├── home.jsp
├── login.jsp
├── META-INF
│ └── MANIFEST.MF
├── styles
│ ├── home
│ └── login
└── WEB-INF
├── lib
│ └── mysql-connector-java-5.1.39-bin.jar
└── web.xml
启动 Servlet 时出现错误
HTTP Status 500 - /login.jsp（行：23，列：11）元素的内容必须由格式正确的字符数据或标记组成。
输入异常报告
message /login.jsp（行：23，列：11）元素的内容必须由格式正确的字符数据或标记组成。
说明服务器遇到内部错误，无法完成此请求。
异常
org.apache.jasper.JasperException: /login.jsp (line: 23, column: 11) The content of elements must consist of well-formed character data or markup.
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:42)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:443)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:308)
org.apache.jasper.compiler.JspDocumentParser.parse(JspDocumentParser.java:228)
org.apache.jasper.compiler.ParserController.doParse(ParserController.java:226)
org.apache.jasper.compiler.ParserController.parseDirectives(ParserController.java:119)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:194)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:374)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:354)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:341)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:662)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
jrservlet.JRServlet.doGet(JRServlet.java:41)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
org.xml.sax.SAXParseException; lineNumber: 23; columnNumber: 11; The content of elements must consist of well-formed character data or markup.
com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177)
com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400)
com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327)
com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1437)
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.startOfMarkup(XMLDocumentFragmentScannerImpl.java:2637)
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2735)
com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:118)
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643)
com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(SAXParserImpl.java:327)
org.apache.jasper.compiler.JspDocumentParser.parse(JspDocumentParser.java:195)
org.apache.jasper.compiler.ParserController.doParse(ParserController.java:226)
org.apache.jasper.compiler.ParserController.parseDirectives(ParserController.java:119)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:194)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:374)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:354)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:341)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:662)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
jrservlet.JRServlet.doGet(JRServlet.java:41)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.70 logs.
Apache Tomcat/7.0.70
好的，问题是不允许在标签内使用 scriplet。相反，您必须将 scriplet 内容包装在 <jsp:scriptlet> 标签内，
<jsp:scriptlet>
out.println((String)request.getAttribute("loginFailed"));
</jsp:scriptlet>
为了允许 c:out 和你需要在你的 jsp:root 元素上包含 JSTL 定义的东西，比如，
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:c="http://java.sun.com/jsp/jstl/core" version="2.0">
其背后的原因是 <jsp:root> 强制使用 XML 语法，因此需要 XML 种常用语法的替代方法，例如 scriptlet。
此外，请参阅更多关于 <jsp:root> here。
并且，XML 符合语法 here。
我正在尝试访问从 Servlet 发送的 JSP 文件数据。
每当我 运行 项目时，我都会收到异常。
我已经尝试使用
- <% … %>
- ${…}
- <c:out value="${loginFailed}"/>
即使我尝试使用评论标签，也会出现异常。
我一无所知，欢迎任何帮助。
我的一些reading/research
https://whosebug.com/tags/el/info
https://www.tutorialspoint.com/jsp/jsp_actions.htm
How to avoid Java code in JSP files?
...
login.jsp
<?xml version="1.0" encoding="UTF-8" ?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.0">
<jsp:directive.page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" />
<jsp:text> <![CDATA[ <?xml version="1.0" encoding="UTF-8" ?> ]]> </jsp:text>
<jsp:text> <![CDATA[ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> ]]> </jsp:text>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<link rel="stylesheet" type="text/css" href="${pageContext.request.contextPath}/styles/login/css/style.css" />
<title>Connexion</title>
</head>
<body>
<form class="sign-up" method="Post" action="/TP1MiniProjetBanque/home">
<h1 class="sign-up-title">Connexion</h1>
<input type="text" name="mail" class="sign-up-input" placeholder="Mail"/>
<input type="password" name="mdp" class="sign-up-input" placeholder="Mot de passe"/>
<input type="submit" value="Entrer" class="sign-up-button"/>
</form>
<% out.println((String)request.getAttribute("loginFailed")); %>
</body>
</html>
</jsp:root>
JRServlet.java
protected void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.getWriter().append("Served at :").append(request.getContextPath());
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
protected void doPost (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String mail = request.getParameter("mail");
String mdp = request.getParameter("mdp");
if (mail.isEmpty() || mdp.isEmpty() || /**/) {
request.setAttribute("loginFailed", true);
request.getRequestDispatcher("/login.jsp").forward(request, response);
return;
} else {
Client user = new Client(mail, mdp);
request.getRequestDispatcher("/home.jsp").forward(request, response);
return;
}
//doGet(request, response);
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>TP1MiniProjetBanque</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>home</servlet-name>
<servlet-class>jrservlet.JRServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>home</servlet-name>
<url-pattern>/home</url-pattern>
</servlet-mapping>
</web-app>
层次结构
workspace/TP1MiniProjetBanque/
├── build
│ └── classes
│ └── jrservlet
│ ├── Client.class
│ ├── Compte.class
│ ├── DB.class
│ ├── JRServlet.class
│ └── testing.class
├── src
│ └── jrservlet
│ ├── Client.java
│ ├── Compte.java
│ ├── DB.java
│ ├── JRServlet.java
│ └── testing.java
└── WebContent
├── home.jsp
├── login.jsp
├── META-INF
│ └── MANIFEST.MF
├── styles
│ ├── home
│ └── login
└── WEB-INF
├── lib
│ └── mysql-connector-java-5.1.39-bin.jar
└── web.xml
启动 Servlet 时出现错误
HTTP Status 500 - /login.jsp（行：23，列：11）元素的内容必须由格式正确的字符数据或标记组成。
输入异常报告
message /login.jsp（行：23，列：11）元素的内容必须由格式正确的字符数据或标记组成。
说明服务器遇到内部错误，无法完成此请求。
异常
org.apache.jasper.JasperException: /login.jsp (line: 23, column: 11) The content of elements must consist of well-formed character data or markup.
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:42)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:443)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:308)
org.apache.jasper.compiler.JspDocumentParser.parse(JspDocumentParser.java:228)
org.apache.jasper.compiler.ParserController.doParse(ParserController.java:226)
org.apache.jasper.compiler.ParserController.parseDirectives(ParserController.java:119)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:194)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:374)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:354)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:341)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:662)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
jrservlet.JRServlet.doGet(JRServlet.java:41)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
org.xml.sax.SAXParseException; lineNumber: 23; columnNumber: 11; The content of elements must consist of well-formed character data or markup.
com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177)
com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400)
com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327)
com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1437)
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.startOfMarkup(XMLDocumentFragmentScannerImpl.java:2637)
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2735)
com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:118)
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643)
com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(SAXParserImpl.java:327)
org.apache.jasper.compiler.JspDocumentParser.parse(JspDocumentParser.java:195)
org.apache.jasper.compiler.ParserController.doParse(ParserController.java:226)
org.apache.jasper.compiler.ParserController.parseDirectives(ParserController.java:119)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:194)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:374)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:354)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:341)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:662)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
jrservlet.JRServlet.doGet(JRServlet.java:41)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.70 logs.
Apache Tomcat/7.0.70
好的，问题是不允许在标签内使用 scriplet。相反，您必须将 scriplet 内容包装在 <jsp:scriptlet> 标签内，
<jsp:scriptlet>
out.println((String)request.getAttribute("loginFailed"));
</jsp:scriptlet>
为了允许 c:out 和你需要在你的 jsp:root 元素上包含 JSTL 定义的东西，比如，
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:c="http://java.sun.com/jsp/jstl/core" version="2.0">
其背后的原因是 <jsp:root> 强制使用 XML 语法，因此需要 XML 种常用语法的替代方法，例如 scriptlet。
此外，请参阅更多关于 <jsp:root> here。
并且，XML 符合语法 here。