使用JSTL访问从Spring Controller到JSP的映射时出错

Question

我有一个弹簧控制器，我在其中返回一个名为“model”的Map;模型包含一些值，但重要的还包含一个ArrayList。现在我将这个Map返回给我的JSP，而在我的JSP中使用JSTL来获取ArrayList它会抛出错误。

<c:forEach items="${model.result}" var="data" varStatus="status"> <!-- result is my ArrayList --> 
    <c:out value="${data.url}" /> <!-- here url is data inside my result arraylist --> 
</c:forEach> 

产生的错误是：

root cause 

java.lang.NoSuchMethodError: javax.servlet.jsp.PageContext.getELContext()Ljavax/el/ELContext; 
    at javax.servlet.jsp.jstl.core.LoopTagSupport.unExposeVariables(LoopTagSupport.java:587) 
    at javax.servlet.jsp.jstl.core.LoopTagSupport.doFinally(LoopTagSupport.java:323) 
    at jsp_servlet._jsp.__searchsuccess._jsp__tag3(__searchsuccess.java:294) 
    at jsp_servlet._jsp.__searchsuccess._jspService(__searchsuccess.java:137) 
    at weblogic.servlet.jsp.JspBase.service(JspBase.java:34) 

它的工作原理Tomcat服务器上的罚款，但是当我Weblogic上部署它（9.2）服务器它给人的错误。我的类路径条目：

<classpathentry kind="con" path="org.eclipse.jst.j2ee.internal.web.container"/> 
    <classpathentry kind="con" path="org.eclipse.jst.j2ee.internal.module.container"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/commons-fileupload-1.1.1.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/commons-io-1.2.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/commons-logging-1.1.1.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/hibernate-validator-4.0.2.GA.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/log4j-1.2.14.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/slf4j-api-1.5.6.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/slf4j-log4j12-1.5.6.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/spring-asm-3.0.3.RELEASE.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/spring-beans-3.0.3.RELEASE.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/spring-context-3.0.3.RELEASE.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/spring-core-3.0.3.RELEASE.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/spring-expression-3.0.3.RELEASE.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/spring-web-3.0.3.RELEASE.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/spring-webmvc-3.0.3.RELEASE.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/validation-api-1.0.0.GA.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/log4j-1.2.9.jar"/> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/servlet-2.3.jar"/> 
    <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/jre6"> 
     <attributes> 
      <attribute name="owner.project.facets" value="jst.java"/> 
     </attributes> 
    </classpathentry> 
    <classpathentry kind="lib" path="WebContent/WEB-INF/lib/jstl-1.2.jar"/> 
    <classpathentry kind="output" path="WebContent/WEB-INF/classes"/> 

---

更新：我已删除了JSTL-1.2.jar现在我得到一个编译错误：

searchsuccess.jsp:1:5: No tag library could be found with this URI. Possible causes could be that the URI is incorrect, or that there were errors during pa 
rsing of the .tld file. 
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
    ^----^ 
searchsuccess.jsp:1:5: No tag library could be found with this URI. Possible causes could be that the URI is incorrect, or that there were errors during pa 
rsing of the .tld file. 
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
    ^----^ 

     at weblogic.servlet.jsp.JavelinxJSPStub.compilePage(JavelinxJSPStub.java:298) 
     at weblogic.servlet.jsp.JspStub.prepareServlet(JspStub.java:200) 
     at weblogic.servlet.jsp.JspStub.prepareServlet(JspStub.java:164) 
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:235) 
     at weblogic.servlet.internal.ServletStubImpl.onAddToMapException(ServletStubImpl.java:394) 

Answer 1

按堆栈跟踪，

java.lang.NoSuchMethodError: javax.servlet.jsp.PageContext.getELContext()Ljavax/el/ELContext; 
    at javax.servlet.jsp.jstl.core.LoopTagSupport.unExposeVariables(LoopTagSupport.java:587) 

JSTL <c:forEach>标签期待的方法PageContext#getELContext()。这个方法在JSP 2.1中引入。因此，此异常表明您正在使用JSTL 1.2，而您的容器不支持JSP 2.1，或者您已将运行时类路径与不支持JSP 2.1的容器的servlet容器特定的JSP库混杂在一起。运行时类路径包括webapp的/WEB-INF/lib文件夹和Java的JRE/lib和JRE/lib/ext文件夹。

你应该从未放servletcontainer在这些文件夹中的特定库，如jsp-api.jar，servlet-api.jar，el-api.jar，j2ee.jar，javaee.jar，etc..etc ..这些文件，你通常在servletcontainer本身的/lib文件夹中看到。例如。 Tomcat/lib。它使你的webapp不可移植到目标servlet容器。您正在运行此Web应用程序的目标servletcontainer有这些库已经。如果你这样做是为了克服JSP/Servlet包的编译错误，那么你应该以不同的方式解决它。另请参见How do I import the javax.servlet API in my Eclipse project?

---

更新：根据您的更新，你使用的Weblogic 9.2这是一个Servlet 2.4/JSP 2.0容器。它根本不支持JSP 2.1/JSTL 1.2。您需要删除JSTL 1.2库。如果我没有弄错，Weblogic已经提供了JSTL 1.1。否则，您需要自己将其包含在类路径（/WEB-INF/lib文件夹）中。您可以在our JSTL wiki page中找到JSTL 1.1下载链接。

Answer 2

你的webapp中是否有el-api.jar？

请看下面的帖子：

http://www.coderanch.com/t/526731/JSP/java/java-lang-NoSuchMethodError-javax-servlet

-Kaj :)