Develop Reference

jsp 3, jstl 1.2 and maven

I use: java 10, Tomcat 7.0.88 with maven
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
In this case I recipes following exception
HTTP Status 500 - The absolute uri: http://java.sun.com/jsp/jstl/core
cannot be resolved in either web.xml or the jar files deployed with
this application
type Exception report
message The absolute uri: http://java.sun.com/jsp/jstl/core cannot be
resolved in either web.xml or the jar files deployed with this
application
description The server encountered an internal error that prevented it
from fulfilling this request.
exception
org.apache.jasper.JasperException: The absolute uri:
http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml
or the jar files deployed with this application
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:56)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:445)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:117)
org.apache.jasper.compiler.TagLibraryInfoImpl.generateTLDLocation(TagLibraryInfoImpl.java:325)
org.apache.jasper.compiler.TagLibraryInfoImpl.(TagLibraryInfoImpl.java:154)
org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:419)
org.apache.jasper.compiler.Parser.parseDirective(Parser.java:484)
org.apache.jasper.compiler.Parser.parseElements(Parser.java:1421)
org.apache.jasper.compiler.Parser.parse(Parser.java:138)
org.apache.jasper.compiler.ParserController.doParse(ParserController.java:242)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:199)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:374)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:354)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:341)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:660)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
todo.TodoServlet.doGet(TodoServlet.java:23)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache
Tomcat/7.0.88 logs. Apache Tomcat/7.0.88

NoClassDefFoundError: org/directwebremoting/extend/ConvertUtil

After moving a Tomcat app from one server to the other, we get this error:
SEVERE: Servlet.service() for servlet dwr-invoker threw exception
java.lang.NoClassDefFoundError: org/directwebremoting/extend/ConvertUtil
at org.directwebremoting.dwrp.CallBatch.parseParameters(CallBatch.java:135)
at org.directwebremoting.dwrp.CallBatch.<init>(CallBatch.java:47)
at org.directwebremoting.dwrp.BaseCallHandler.handle(BaseCallHandler.java:72)
at org.directwebremoting.servlet.UrlProcessor.handle(UrlProcessor.java:120)
at org.directwebremoting.servlet.DwrServlet.doPost(DwrServlet.java:141)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
We have the dwr.jar in the WEB-INF/lib dir (and I opened it and checked, the org/directwebremoting/extend/ConvertUtil is there)
/srv/tomcat6/webapps/APPNAME/WEB-INF/lib/dwr.jar
UPDATE this is how DWR dependency is defined in the pom.xml
<dependency>
<groupId>org.directwebremoting</groupId>
<artifactId>dwr</artifactId>
<version>3.rc1</version>
<scope>system</scope>
<systemPath>${basedir}/src/main/webapp/WEB-INF/lib/dwr.jar</systemPath>
</dependency>

HTTP Status 500 - Unable to compile class for JSP: in Eclipse Luna

I have a Login.jsp page.When I try to run it on server I get the following error:
type Exception report
message Unable to compile class for JSP:
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: Unable to compile class for JSP:
An error occurred at line: [1] in the generated java file:
The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files
Stacktrace:
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:103)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:366)
org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:468)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:378)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.47 logs.
What causes this error?

I found the solution I changed from Apache 7 to Apache 8 now things are working fine !

Correct way to solve "javax.servlet.ServletException: java.lang.LinkageError: loader constraint violation"?

I moved my war file (which ran on tomcat 7 environment) to tomcat 6 environment.Then I get this exception .And as solutions I tried This answer.But still no good!! I want to run on a remote machine which has tomcat 6 only.Please help me out..
Exception
javax.servlet.ServletException: java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/catalina/loader/WebappClassLoader) previously initiated loading for a different type with name "javax/el/ExpressionFactory"
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:268)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1047)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:817)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/catalina/loader/WebappClassLoader) previously initiated loading for a different type with name "javax/el/ExpressionFactory"
java.lang.ClassLoader.defineClass1(Native Method)
java.lang.ClassLoader.defineClass(ClassLoader.java:800)
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2331)
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:976)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1451)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1329)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:128)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:66)
java.lang.Class.getDeclaredFields0(Native Method)
java.lang.Class.privateGetDeclaredFields(Class.java:2397)
java.lang.Class.getDeclaredFields(Class.java:1806)
org.apache.catalina.util.DefaultAnnotationProcessor.processAnnotations(DefaultAnnotationProcessor.java:181)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:148)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1047)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:817)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

You have two versions of the expression language in you classpath. The one loaded by your app is not compatible to your servers one. Have a look at a file called javax.el-api, commons-el, or jboss-el-api, etc. Try to remove that from your app, since Tomcat shipps with its own.

I was stuck with this error for a very long time. Adding some research I did before resolving this issue. Yes we need to remove libraries like jsp-api.jar, el-api.jar, servlet-api.jar from /WEB-INF/lib folder. But how?
In my case I am using Apache Ivy as a dependency manger and used Spring MVC. It downloads all dependencies along with the libraries mentioned above. At runtime these conflicts with the APIs provided by Tomcat libraries. Simple solution would be to exclude these jars from dependencies or create configurations and include these libraries in compile time configuration only. What worked for me quickly is excluding these libraries.
<dependency org="org.springframework" name="spring-webmvc"
rev="4.0.4.RELEASE">
<exclude org="javax.servlet" name="javax.servlet-api" />
<exclude org="javax.servlet.jsp" name="jsp-api" />
<exclude org="javax.el" name="javax.el-api" />
</dependency>

Error while deploying java webservice

Could someone help me on this.
I have created simple java web service using Java 1.6, tomcat-6.0.20 and axis2-1.4.1.
While deploying the application, it returns following error message:
SEVERE: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: Unable to compile class for JSP:
An error occurred at line: 22 in the generated java file
The method getJspApplicationContext(ServletContext) is undefined for the type JspFactory
Stacktrace:
at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:92)
at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:439)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:334)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:312)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:299)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:586)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
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.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
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:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Thread.java:619)
Feb 25, 2010 11:58:37 PM org.apache.catalina.core.ApplicationDispatcher invoke
SEVERE: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: Unable to compile class for JSP:

Seems that there is an incompatibility of libraries loaded.
See this post and this
The first post explain the error:
In Tomcat 6, the JSP API classes are found in jsp-api.jar and servlet
API classes are found in servlet-api.jar, with both located in the lib
directory of the Tomcat 6 installation. Any servlet.jar you find
involved with this server would contain out of date classes for this
server.
So... check if you don't have an extra servlet.jar:
Make sure you don't
have a copy of servlet.jar in the WEB-INF/lib of your webapp or
somewhere else involved with the running server, such as in the
lib/ext directory of your JDK or JRE.
I hope it helps you.