Exception Handler Implementation

Custom Exception Hendler Class

Create a custom exception handler by implementing the HandlerExceptionResolver interface:

package com.example.exceptions;

import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class CustomExceptionHandler implements HandlerExceptionResolver {
    @Override
    public ModelAndView resolveException(HttpServletRequest request, 
                                       HttpServletResponse response, 
                                       Object handler, 
                                       Exception exception) {
        ModelAndView model = new ModelAndView();
        model.addObject("errorMessage", exception.getMessage());
        model.setViewName("error-page");
        return model;
    }
}

Spring MVC Configuration for Expection Handling

Configure the expection handler in your Spring MVC configuration file:

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <context:component-scan base-package="com.example"/>
    
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
    
    <bean id="customExceptionHandler" class="com.example.exceptions.CustomExceptionHandler"/>
    
    <mvc:annotation-driven/>
</beans>

Interceptor Implementation

Custom Interceptor Class

Implement the HandlerInterceptor interface to create a custom interceptor:

package com.example.interceptors;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class RequestInterceptor implements HandlerInterceptor {
    
    @Override
    public boolean preHandle(HttpServletRequest request, 
                           HttpServletResponse response, 
                           Object handler) throws Exception {
        System.out.println("Executing before controller method");
        return true; // true: proceed, false: block
    }

    @Override
    public void postHandle(HttpServletRequest request, 
                          HttpServletResponse response, 
                          Object handler, 
                          ModelAndView model) throws Exception {
        System.out.println("Executing after controller method");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, 
                              HttpServletResponse response, 
                              Object handler, 
                              Exception ex) throws Exception {
        System.out.println("Executing after view rendering");
    }
}

Spring MVC Configuration for Interceptors

Configure interceptors in your Spring MVC configuration:

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <context:component-scan base-package="com.example"/>
    
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
    
    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <bean class="com.example.interceptors.RequestInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>
    
    <mvc:annotation-driven/>
</beans>