SimpleMappingExceptionResolver not Resolving 404

Below is my spring configuration file:

<bean class="com.web.handler.CustomSimpleMappingExceptionResolver" >
    <property name="exceptionMappings">
        <props>              
            <prop key="java.lang.Throwable">error</prop>
        </props>
    </property>
</bean>

Class CustomSimpleMappingExceptionResolver

public class CustomSimpleMappingExceptionResolver extends SimpleMappingExceptionResolver{
    @Override
    public ModelAndView resolveException(HttpServletRequest request,
            HttpServletResponse response, Object handler, Exception ex) {

    if(int a = 1)
        return new ModelAndView("ViewName1");
    else
        return new ModelAndView("ViewName2");
    }

My web.xml has no error page. I am looking to show different view according to my logic in resolveException().

In CustomSimpleMappingExceptionResolver class resolveException() is not being called in case of 404.

Solution

Set error page in web.xml

<error-page>
    <error-code>404</error-code>
    <location>/error.html</location>
</error-page>

your error page will redirect as soon as it opened.

<html>
    <head>
    <title>Your Page Title</title>
    <meta http-equiv="REFRESH" content="0;url=error.htm">
    </head>
    <body>
    </body>
</html>

There should be a request mapping in your controller to handle error.htm request.

@RequestMapping(value={"/error.htm"})
    ModelAndView routToErrorHandler(HttpServletRequest request, HttpServletResponse response) {
//any logic for your themes
}