Spring - Hibernate error

Question

I have a web application connected to a MySQL database.

This application implements the Frameworks Spring and Hibernate, and it has the following architecture:

In the file getGraph.jsp I have this code:

<%@page import="org.springframework.beans.factory.annotation.Autowired"%>
<%@page import="com.google.gson.*"%>
<%@page import="com.fdl.entity.*"%>
<%@page import="com.fdl.dao.*"%>
<%@page import="java.io.PrintWriter"%>
<%@page import="org.springframework.context.support.ClassPathXmlApplicationContext" %>
<%@page import="org.springframework.context.ApplicationContext" %>

   <%
    response.setContentType("application/json;charset=UTF-8");
    Gson gson = new Gson();
    ApplicationContext context = new ClassPathXmlApplicationContext("/applicationContext.xml");
    FdlDao fdlDao=(FdlDao) context.getBean("fdlDao");
    Graph graph = fdlDao.getGraph2();
    out.print(gson.toJson(graph));
   %>

But when I run the code I get this error:

7 mars 2014 23:27:54 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@15b4b49: startup date [Fri Mar 07 23:27:54 WET 2014]; root of context hierarchy
7 mars 2014 23:27:54 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [applicationContext.xml]
7 mars 2014 23:27:54 org.apache.catalina.core.StandardWrapperValve invoke
GRAVE: Servlet.service() for servlet [jsp] in context with path [/FDL] threw exception [An exception occurred processing JSP page /getGraph.jsp at line 14

11: 
12:     response.setContentType("application/json;charset=UTF-8");
13:     Gson gson = new Gson();
14:     ApplicationContext context = new ClassPathXmlApplicationContext("/applicationContext.xml");
15:     FdlDao fdlDao=(FdlDao) context.getBean("fdlDao");
16:     Graph graph = fdlDao.getGraph2();
17:     out.print(gson.toJson(graph));


Stacktrace:] with root cause
java.io.FileNotFoundException: class path resource [applicationContext.xml] cannot be opened because it does not exist
at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:157)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:328)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:174)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:209)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:180)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:243)
at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:127)
at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:93)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:130)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:537)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:451)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at org.apache.jsp.getGraph_jsp._jspService(getGraph_jsp.java:82)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:679)

What is the problem? And how can I solve it?

Answer 1

The message explains it:

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

The classpath of a webapp is made of the WEB-INF/classes folder and of all the jars under WEB-INF/lib. The applicationContext.xml is under WEB-INF, so it's not in the classpath.

Note that this is not how you should use Spring:

• scriptlets shouldn't be used
• calling s DAO should not be done from a JSP, which is a view component which should only generate HTML. Calling a DAO is the job of a controller, written in Java
• JSPs are view components and should never be accessed directly. Always through a controller.
• creating a new Spring context at each request is extremely costly. The context should be started when the application is deployed, once and for all.

The way to use Spring in a webapp is decribed in the Spring documentation. Read it, and use Spring MVC as documented.