java - SEVERE: Allocate exception for servlet, error when trying to call a servlet from JSP page -

when run jsp on tomcat server , runs ok, when click submit throws following error, have checked on , not sure go here because seems should work, appreciated, thank you.

error stack trace:

severe: allocate exception servlet registrationservlet java.lang.classnotfoundexception: logon.registrationservlet.java @ org.apache.catalina.loader.webappclassloader.loadclass(webappclassloader.java:1720) @ org.apache.catalina.loader.webappclassloader.loadclass(webappclassloader.java:1571) @ org.apache.catalina.core.defaultinstancemanager.loadclass(defaultinstancemanager.java:529) @ org.apache.catalina.core.defaultinstancemanager.loadclassmaybeprivileged(defaultinstancemanager.java:511) @ org.apache.catalina.core.defaultinstancemanager.newinstance(defaultinstancemanager.java:139) @ org.apache.catalina.core.standardwrapper.loadservlet(standardwrapper.java:1148) @ org.apache.catalina.core.standardwrapper.allocate(standardwrapper.java:864) @ org.apache.catalina.core.standardwrappervalve.invoke(standardwrappervalve.java:134) @ org.apache.catalina.core.standardcontextvalve.invoke(standardcontextvalve.java:122) @ org.apache.catalina.authenticator.authenticatorbase.invoke(authenticatorbase.java:501) @ org.apache.catalina.core.standardhostvalve.invoke(standardhostvalve.java:170) @ org.apache.catalina.valves.errorreportvalve.invoke(errorreportvalve.java:98) @ org.apache.catalina.valves.accesslogvalve.invoke(accesslogvalve.java:950) @ org.apache.catalina.core.standardenginevalve.invoke(standardenginevalve.java:116) @ org.apache.catalina.connector.coyoteadapter.service(coyoteadapter.java:408) @ org.apache.coyote.http11.abstracthttp11processor.process(abstracthttp11processor.java:1040) @ org.apache.coyote.abstractprotocol$abstractconnectionhandler.process(abstractprotocol.java:607) @ org.apache.tomcat.util.net.jioendpoint$socketprocessor.run(jioendpoint.java:315) @ java.util.concurrent.threadpoolexecutor.runworker(unknown source) @ java.util.concurrent.threadpoolexecutor$worker.run(unknown source) @ java.lang.thread.run(unknown source) 

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"  xmlns:web="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_2_5.xsd"  id="webapp_id" version="2.5"> <display-name>registrationtest</display-name>  <servlet>         <display-name>registrationservlet</display-name>         <servlet-name>registrationservlet</servlet-name>         <servlet-class>logon.registrationservlet</servlet-class>  </servlet>  <servlet-mapping>      <servlet-name>registrationservlet</servlet-name>      <url-pattern>/registrationservlet</url-pattern>  </servlet-mapping> </web-app> 

the jsp page:

<h2>signup details</h2>         <form name="actionform" action="registrationservlet" method ="post">         <br/>username:<input type="text" name="name">         <br/>password:<input type="password" name="password">         <br/>email:<input type="text" name="email">         <br/><input type="submit" value="submit">         </form> 

the servlet:

import java.io.ioexception; import javax.servlet.servletexception; import javax.servlet.annotation.webservlet; import javax.servlet.http.httpservlet; import javax.servlet.http.httpservletrequest; import javax.servlet.http.httpservletresponse;  /**   * servlet implementation class registrationservlet  */ @webservlet("/registrationservlet") public class registrationservlet extends httpservlet { private static final long serialversionuid = 1l;  public registrationservlet() {     super();  }   protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {  }   protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {     try{         system.out.println("in registration servlet");         user user = new user();         user.setname(request.getparameter("name"));         user.setpassword(request.getparameter("password"));         user.setemail(request.getparameter("email"));         registeruser.adduser(user);         //response.sendredirect("welcome.jsp");             } catch (throwable exc)     {         system.out.println(exc);     } }  } 

for has similar problem in future, after cleaning project, ensure build automatically box checked under project drop down menu required rebuild after clean, mine unchecked default reason.

also made small error in code, used annotations (@webservlet) in servlet , added servlet web.xml caused conflict. done automatically annotations.