java.lang.ClassCastException: org.apache.catalina.core.DefaultInstanceManager cannot be cast to org.apache.tomcat.InstanceManager

Question

I am making a simple spring project that performs CRUD operations.

I am using tomacat 7.0.96 and i have also explicitly mentioned tomcat version 7.0.96 in the POM.xml Here is my POM

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>

    <dependency>  
    <groupId>org.springframework</groupId>  
    <artifactId>spring-webmvc</artifactId>  
    <version>5.1.1.RELEASE</version>  
</dependency>  

<!-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-jasper -->  
<dependency>  
    <groupId>org.apache.tomcat</groupId>  
    <artifactId>tomcat-jasper</artifactId>  
    <version>7.0.96</version>  
</dependency>  
    <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->  
<dependency>    
    <groupId>javax.servlet</groupId>    
    <artifactId>servlet-api</artifactId>    
    <version>3.0-alpha-1</version>    
</dependency>  
<!-- https://mvnrepository.com/artifact/javax.servlet/jstl -->  
<dependency>  
    <groupId>javax.servlet</groupId>  
    <artifactId>jstl</artifactId>  
    <version>1.2</version>  
</dependency>  
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->  
<dependency>  
    <groupId>mysql</groupId>  
    <artifactId>mysql-connector-java</artifactId>  
    <version>8.0.11</version>  
</dependency>  
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->  
<dependency>  
    <groupId>org.springframework</groupId>  
    <artifactId>spring-jdbc</artifactId>  
    <version>5.1.1.RELEASE</version>  
</dependency>  

And yes my tomcat lib has jsp-api.jar and servlet-api.jar, jasper.jar and catalina.jar in it. and i have also tried cleaning the project and rebuilding it i have also restarted the server before running the project on server.

I dont know why i keep getting this error

SEVERE: Servlet.service() for servlet [jsp] in context with path [/Spring_prac] threw exception [java.lang.ClassCastException: org.apache.catalina.core.DefaultInstanceManager cannot be cast to org.apache.tomcat.InstanceManager] with root cause java.lang.ClassCastException: org.apache.catalina.core.DefaultInstanceManager cannot be cast to org.apache.tomcat.InstanceManager

heres my web.xml and spring-servlet

WEB.xml

<?xml version="1.0" encoding="UTF-8"?>  
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">  
  <display-name>SpringMVC</display-name>  
   <servlet>    
    <servlet-name>spring</servlet-name>    
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>    
    <load-on-startup>1</load-on-startup>      
</servlet>    
<servlet-mapping>    
    <servlet-name>spring</servlet-name>    
    <url-pattern>/</url-pattern>    
</servlet-mapping>    
</web-app>  

Spring-servlet

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
    xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xsi:schemaLocation="  
        http://www.springframework.org/schema/beans  
        http://www.springframework.org/schema/beans/spring-beans.xsd  
        http://www.springframework.org/schema/context  
        http://www.springframework.org/schema/context/spring-context.xsd  
        http://www.springframework.org/schema/mvc  
        http://www.springframework.org/schema/mvc/spring-mvc.xsd">  
<context:component-scan base-package="com.javatpoint.controllers"></context:component-scan>    

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">    
<property name="prefix" value="/WEB-INF/jsp/"></property>    
<property name="suffix" value=".jsp"></property>    
</bean>    

<bean id="ds" class="org.springframework.jdbc.datasource.DriverManagerDataSource">    
<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>    
<property name="url" value="jdbc:mysql://localhost:3306/db1"></property>    
<property name="username" value="root"></property>    
<property name="password" value="neonowl"></property>    
</bean>    

<bean id="jt" class="org.springframework.jdbc.core.JdbcTemplate">    
<property name="dataSource" ref="ds"></property>    
</bean>    

<bean id="dao" class="com.javatpoin.dao.EmployeeDao">    
<property name="template" ref="jt"></property>    
</bean>       
</beans>  

Please help me fix this, i'm really frustrated.

Here's the error log

Sep 26, 2019 6:15:59 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [jsp] in context with path [/Spring_prac] threw exception [java.lang.ClassCastException: org.apache.catalina.core.DefaultInstanceManager cannot be cast to org.apache.tomcat.InstanceManager] with root cause
java.lang.ClassCastException: org.apache.catalina.core.DefaultInstanceManager cannot be cast to org.apache.tomcat.InstanceManager
    at org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(InstanceManagerFactory.java:29)
    at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:192)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:409)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:444)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:1025)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1137)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:317)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

Answer 1

I solved it by removing the tomcat-jasper dependency in the POM.

Actually i've added the external library for tomcat v7.0 and then i've added the dependency for tomcat again in the POM. There's no need to add the dependency for tomcat in the POM.