JSP 解决illegal to have multiple occurrences of contentType with different values错误
在一个项目jsp文件中包含了另一个jsp文件（proCitySelAll.jsp），执行出现如下错误：
2012-5-14 16:37:04 org.apache.catalina.core.ApplicationDispatcher invoke
严重: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: /lightworkflow/sheet/depponOrder/proCitySelAll.jsp(1,2) Page directive: illegal to have multiple occurrences of contentType with different values (old: text/html; charset=UTF-8, new: text/html; charset=utf-8)
at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.Java:40)
at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:407)
at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:236)
at org.apache.jasper.compiler.Validator$DirectiveVisitor.visit(Validator.java:132)
at org.apache.jasper.compiler.Node$PageDirective.accept(Node.java:608)
at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361)
at org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2411)
at org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2417)
at org.apache.jasper.compiler.Node$Root.accept(Node.java:495)
at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361)
at org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2411)
at org.apache.jasper.compiler.Validator$DirectiveVisitor.visit(Validator.java:99)
at org.apache.jasper.compiler.Node$IncludeDirective.accept(Node.java:656)
at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361)
at org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2411)
at org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2417)
at org.apache.jasper.compiler.Node$Root.accept(Node.java:495)
at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361)
at org.apache.jasper.compiler.Validator.validateDirectives(Validator.java:1723)
at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:182)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:347)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:327)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:314)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:592)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:326)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1063)
at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:386)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:229)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.hollycrm.service.system.web.PageCacheFilter.doFilter(PageCacheFilter.java:50)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.hollycrm.service.license.LicenseFilter.doFilter(LicenseFilter.java:47)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.hollycrm.service.system.security.web.filter.LoginUserInfoFilter.doFilter(LoginUserInfoFilter.java:167)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.hollycrm.framework.web.filter.RequestEncodeFilter.doFilter(RequestEncodeFilter.java:46)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.hollycrm.service.system.web.PageCacheFilter.doFilter(PageCacheFilter.java:50)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.NET.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)
proCitySelAll.jsp 代码是没有错的，因为在其它页面调用没有出错过。那么是主文件出错了，看了一下刚写的页面全是静态内容，没什么的？
仔细阅读错误信息：
Page directive: illegal to have multiple occurrences of contentType with different values (old: text/html; charset=utf-8,new: text/html;charset=utf-8)
原来是包含页面与被包含页面的@page指令里面的contentType不一致，仔细检查两个文件第一行的 @page，
包含页面的是： <%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
被包含页面： <%@ page language="java" contentType="text/html;charset=utf-8" pageEncoding="utf-8"%>
果然contentType="text/html;和charset=utf-8"之间多了一个空格，把两个文件第一行的@page内容改为一致，再执行程序，运行通过。
总结：被包含页面和包含页面必须都加上@page 头内容这个asp正好相反的，而且值要一致
如果你是 <%@ include file="/WEB-INF/jsp/common/head.jsp"%>
那么改为<jsp:include page="/WEB-INF/jsp/common/head.jsp" >
如果你是<jsp:include page="/WEB-INF/jsp/common/head.jsp" >
那么改为<%@ include file="/WEB-INF/jsp/common/head.jsp"%>
