have different Class objects for the type javax.el used in the signature

Problem
=======
have different Class objects for the type javax.el used in the signature

Solution
========
dependency>
groupId>javax.el/groupId>
artifactId>el-api/artifactId>
version>1.0/version>
scopeprovidedscope

JSTL-1.2.jar crash with apache-taglibs-standard-1.1.2.jar ; have different Class objects

java.lang.LinkageError: loader constraint violation: when resolving interface method "javax.servlet.jsp.JspApplicationContext.getExpressionFactory()Ljavax/el/ExpressionFactory;" the class loader (instance of org/apache/jasper/servlet/JasperLoader) of the current class, org/apache/jsp/WEB_002dINF/jsp/about_jsp, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, javax/servlet/jsp/JspApplicationContext, have different Class objects for the type javax/el/ExpressionFactory used in the signature
org.apache.jsp.WEB_002dINF.jsp.about_jsp._jspInit(about_jsp.java:22)

Can not find tag lib of JSTL<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

Problem of taglib can not resolve

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

Solution
========

javax.servlet
servlet-api
2.5
provided


javax.servlet.jsp
jsp-api
2.1
provided


javax.servlet
jstl

1.2

class path resource [beans.xml] cannot be opened because it does not exist

class path resource [beans.xml] cannot be opened because it does not exist

Even the beans.xml exist in resource folder, but IDE can't get it.
Solution:
(1)Try to compile it first, then run again.

(2)Go to Build path remove the ** under Excluded.

(3)Change .classpath
change .classpath





Eclipse problem

Installing 3rd party JARs to Local Repository

mvn install:install-file -Dfile= -DgroupId= \
-DartifactId= -Dversion= -Dpackaging=

Sample
======
mvn install:install-file -Dfile=jboss-jca-api.jar -DgroupId=org.jboss.javaee -DartifactId=jboss-jca-api -Dversion=1.5.0.CR2 -Dpackaging=jar

Project + Example

Project + Example

Session object -> set & get

HttpSession session = httpServletRequest.getSession();

Usage
=====
(1)Type object = (Type) session.getAttribute("name");

(2)session.setAttribute("name", object);

Error : java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

Problem
=======
SEVERE: Error configuring application listener of class org.springframework.web.context.ContextLoaderListener java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

Solution
========
Checking "Automatically update dependencies" in Project Properties -> Spring -> Dependency Management.