Java for Web学习笔记（三八）：自定义tag（6）一些注意

引入的base.jspf

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><%@ page import="cn.wei.flowingflying.customer_support.Ticket,cn.wei.flowingflying.customer_support.Attachment" %><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %><%@ taglib prefix="wrox" uri="http://www.wrox.com/jsp/tld/wrox" %><%@ taglib prefix="template" tagdir="/WEB-INF/tags/template" %>

会报错：

org.apache.jasper.JasperException: /WEB-INF/tags/template/loggedOut.tag (line: 4, column: 1) /WEB-INF/jsp/base.jspf (line: 1, column: 9) <%@ page directive cannot be used in a tag file

需要修订为

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %><%@ taglib prefix="wrox" uri="http://www.wrox.com/jsp/tld/wrox" %><%@ taglib prefix="template" tagdir="/WEB-INF/tags/template" %>

在jsp的注释中，尽可能不要写入<>

<!-- At this point the attribute is specified within the tag body content, so to specify the real tag bodycontent you need to use the <jsp:body> tag.  -->会报错：org.apache.jasper.JasperException: /WEB-INF/tags/template/loggedOut.tag (line: 10, column: 1) Must use jsp:body to specify tag body for <template:main if jsp:attribute is used.改为：<!-- At this point the attribute is specified within the tag body content, so to specify the real tag bodycontent you need to use the jsp:body tag.  -->

jsp:attribute和jsp:body之间不要加入注释

<template:main htmlTitle="${htmlTitle}" bodyTitle="${bodyTitle}"><jsp:attribute name="headContent"><link rel="stylesheet" href="<c:url value="/resource/stylesheet/login.css" />" /></jsp:attribute><jsp:attribute name="navigationContent" /><!-- At this point the attribute is specified within the tag body content, so to specify the real tag bodycontent you need to use the jsp:body tag.  --><jsp:body><jsp:doBody /></jsp:body></template:main>这会报错：十一月 30, 2016 9:07:18 上午 org.apache.catalina.core.ApplicationDispatcher invoke严重: Servlet.service() for servlet jsp threw exceptionorg.apache.jasper.JasperException: /WEB-INF/tags/template/loggedOut.tag (line: 10, column: 1) Must use jsp:body to specify tag body for <template:main if jsp:attribute is used.at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:41)at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:275)at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:91)at org.apache.jasper.compiler.Parser.parseJspAttributeAndBody(Parser.java:1044)at org.apache.jasper.compiler.Parser.parseOptionalBody(Parser.java:1004)at org.apache.jasper.compiler.Parser.parseCustomTag(Parser.java:1281)at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1460)at org.apache.jasper.compiler.Parser.parse(Parser.java:139)at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:227)at org.apache.jasper.compiler.ParserController.parse(ParserController.java:100)at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:199)at org.apache.jasper.compiler.Compiler.compile(Compiler.java:356)at org.apache.jasper.compiler.Compiler.compile(Compiler.java:336)at org.apache.jasper.compiler.Compiler.compile(Compiler.java:323)at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:585)at org.apache.jasper.servlet.JspServletWrapper.loadTagFile(JspServletWrapper.java:246)at org.apache.jasper.compiler.TagFileProcessor.loadTagFile(TagFileProcessor.java:587)at org.apache.jasper.compiler.TagFileProcessor.access$000(TagFileProcessor.java:50)at org.apache.jasper.compiler.TagFileProcessor$TagFileLoaderVisitor.visit(TagFileProcessor.java:674)at org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1536)at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2376)at org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2428)at org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2434)at org.apache.jasper.compiler.Node$Root.accept(Node.java:464)at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2376)at org.apache.jasper.compiler.TagFileProcessor.loadTagFiles(TagFileProcessor.java:692)at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:229)at org.apache.jasper.compiler.Compiler.compile(Compiler.java:356)at org.apache.jasper.compiler.Compiler.compile(Compiler.java:336)at org.apache.jasper.compiler.Compiler.compile(Compiler.java:323)at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:585)at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:363)at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:720)at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466)at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391)at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)at cn.wei.flowingflying.customer_support.LoginServlet.doGet(LoginServlet.java:55)at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)at java.lang.Thread.run(Unknown Source)

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