In J2EE / servlet web application, you can map error page to specify exception like this :

web.xml
  <error-page>
	<error-code>404</error-code>
	<location>/WEB-INF/pages/404.jsp</location>
  </error-page>
 
  <error-page>
	<exception-type>com.mkyong.web.exception.CustomException</exception-type>
	<location>/WEB-INF/pages/error/custom_error.jsp</location>
  </error-page>
 
  <error-page>
	<exception-type>java.lang.Exception</exception-type>
	<location>/WEB-INF/pages/generic_error.jsp</location>
  </error-page>

The above code should be self-exploratory. If the exception handling function exists in the servlet container, why we still need to use the Spring to handle the exception?

Generally, there are two reasons :

  1. Customize Error Page – The servlet container will render the error page directly; While the Spring allows you to populate model or data to the error page, so that you can customize a more user friendly error page.
  2. Business logic – Spring allow you to apply extra business logic before rendering the error page, like logging, auditing and etc.

In this tutorial, we will show you two examples to handle the exception in Spring.

  1. For Spring 2.x, we use SimpleMappingExceptionResolver in the XML file.
  2. For Spring 3.x, we can simplify the XML configuration via @ExceptionHandler annotation.

1. SimpleMappingExceptionResolver Example

Review the directory structure.

spring-mvc-exception-example-directory

A custom exception.

CustomGenericException.java
package com.mkyong.web.exception;
 
public class CustomGenericException extends RuntimeException {
 
	private static final long serialVersionUID = 1L;
 
	private String errCode;
	private String errMsg;
 
	//getter and setter methods
 
	public CustomGenericException(String errCode, String errMsg) {
		this.errCode = errCode;
		this.errMsg = errMsg;
	}
 
}

This controller class, just throw a CustomGenericException with custom error code and error description.

CustomerController.java
package com.mkyong.web.controller;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.AbstractController;
import com.mkyong.web.exception.CustomGenericException;
 
public class CustomerController extends AbstractController {
 
  @Override
  protected ModelAndView handleRequestInternal(HttpServletRequest request,
	HttpServletResponse response) throws Exception {
 
	throw new CustomGenericException("E888", "This is custom message - ABC");
 
  }
 
}

Review the SimpleMappingExceptionResolver below :

mvc-dispatcher-servlet.xml
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="
        http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/mvc 
	http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 
	<context:component-scan base-package="com.mkyong" />
 
	<bean
	class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping"/>
 
	<!-- Register the bean -->
	<bean class="com.mkyong.web.controller.CustomerController" />
 
	<bean
	  class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
	  <property name="exceptionMappings">
		<props>
			<prop key="com.mkyong.wb.exception.CustomGenericException">
				error/generic_error
			</prop>
			<prop key="java.lang.Exception">error/exception_error</prop>
		</props>
	  </property>
	</bean>
 
	<bean
	  class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix">
			<value>/WEB-INF/pages/</value>
		</property>
		<property name="suffix">
			<value>.jsp</value>
		</property>
	</bean>
 
	<mvc:annotation-driven />
 
</beans>

In above, when

  1. CustomGenericException is thrown, it will map to the view name “error/generic_error”.
  2. Any other Exceptions is thrown, it will map to the view name “error/exception_error”.

In the JSP page, you can access the exception instance via ${exception}.

pages/error/generic_error.jsp.jsp
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<body>
 
	<c:if test="${not empty exception.errCode}">
		<h1>${exception.errCode} : System Errors</h1>
	</c:if>
 
	<c:if test="${empty exception.errCode}">
		<h1>System Errors</h1>
	</c:if>
 
	<c:if test="${not empty exception.errMsg}">
		<h4>${exception.errMsg}</h4>
	</c:if>
 
</body>
</html>

Demo – http://localhost:8080/SpringMvcExample/customer

spring-mvc-exception-handle-1

2. @ExceptionHandler Example

Since Spring 3.0, there is a new annotation @ExceptionHandler to simplify the XML configuration. Below is the equivalent version using @ExceptionHandler.

CustomerController.java
package com.mkyong.web.controller;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
import com.mkyong.web.exception.CustomGenericException;
 
@Controller
public class CustomerController {
 
	@RequestMapping(value = "/customer", method = RequestMethod.GET)
	public ModelAndView getPages() throws Exception {
 
		throw new CustomGenericException("E888", "This is custom message X");
 
	}
 
	@ExceptionHandler(CustomGenericException.class)
	public ModelAndView handleCustomException(CustomGenericException ex) {
 
		ModelAndView model = new ModelAndView("error/generic_error");
		model.addObject("exception", ex);
		return model;
 
	}
 
	@ExceptionHandler(Exception.class)
	public ModelAndView handleAllException(Exception ex) {
 
		ModelAndView model = new ModelAndView("error/exception_error");
		return model;
 
	}
 
}

Nothing to declare in Spring XML file.

mvc-dispatcher-servlet.xml
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="
        http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/mvc 
		http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 
	<context:component-scan base-package="com.mkyong" />
 
	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix">
			<value>/WEB-INF/pages/</value>
		</property>
		<property name="suffix">
			<value>.jsp</value>
		</property>
	</bean>
 
	<mvc:annotation-driven />
 
</beans>
Note
You may interest at this Spring MVC @ExceptionHandler Example

Reference

  1. SimpleMappingExceptionResolver JavaDoc
  2. @ExceptionHandler JavaDoc
  3. Spring MVC @ExceptionHandler Example
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