Table of Contents
Lets understand this with the help of example:
Maven dependencies
2) Our pom.xml will look like below
pom.xml
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 |
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.arpit.java2blog</groupId> <artifactId> SpringMVCControllerAdviceExample</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name> SpringMVCControllerAdviceExample Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.4.1</version> </dependency> </dependencies> <build> <finalName> SpringMVCControllerAdviceExample</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.1</version> <configuration> <source>${jdk.version}</source> <target>${jdk.version}</target> </configuration> </plugin> </plugins> </build> <properties> <spring.version>4.2.1.RELEASE</spring.version> <jdk.version>1.7</jdk.version> </properties> </project> |
Spring application configuration:
3) Change web.xml as below:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
<?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" version="3.0"> <display-name>Archetype Created Web Application</display-name> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>springrest</servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springrest</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app> |
4) create a xml file named springrest-servlet.xml in /WEB-INF/ folder.
Please change context:component-scan if you want to use different package for spring to search for controller.Please refer to spring mvc hello world example for more understanding.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 |
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> <mvc:annotation-driven/> <context:component-scan base-package="org.arpit.java2blog.controller" /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix"> <value>/WEB-INF/</value> </property> <property name="suffix"> <value>.jsp</value> </property> </bean> <mvc:default-servlet-handler/> </beans> |
Create Controller
6) Create a controller named “HelloWorldController.java” in package org.arpit.java2blog.controller
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 |
package org.arpit.java2blog.controller; import java.io.IOException; import org.apache.log4j.Logger; import org.arpit.java2blog.exception.CustomException; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.ExceptionHandler; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.servlet.ModelAndView; @Controller public class HelloWorldController { private static final Logger logger = Logger .getLogger(HelloWorldController.class); @RequestMapping("/helloworld/{helloType}") public ModelAndView hello(@PathVariable("helloType") String helloType) throws CustomException, IOException { String helloWorldMessage=""; if (helloType.equalsIgnoreCase("CustomException")) { throw new CustomException("Custom exception occured"); } else if (helloType.equalsIgnoreCase("IOException")) { throw new IOException(" IO exception occured"); } else { helloWorldMessage = "Hello world from java2blog!"; } return new ModelAndView("hello", "message", helloWorldMessage); } @ExceptionHandler(CustomException.class) public ModelAndView catchCustomException(CustomException ex) { ModelAndView model = new ModelAndView("Custom_Exception"); model.addObject("errorMessage", ex.getMessage()); return model; } @ExceptionHandler(IOException.class) public ModelAndView catchIOException(IOException ex) { ModelAndView model = new ModelAndView("IOException"); model.addObject("errorMessage", ex.getMessage()); return model; } } |
Create ControllerAdvice named GlobalExceptionController.java
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 |
package org.arpit.java2blog.controller; import java.io.IOException; import org.arpit.java2blog.exception.CustomException; import org.springframework.web.bind.annotation.ControllerAdvice; import org.springframework.web.bind.annotation.ExceptionHandler; import org.springframework.web.servlet.ModelAndView; @ControllerAdvice public class GlobalExceptionController { @ExceptionHandler(CustomException.class) public ModelAndView catchCustomException(CustomException ex) { ModelAndView model = new ModelAndView("Custom_Exception"); model.addObject("errorMessage", ex.getMessage()); return model; } @ExceptionHandler(IOException.class) public ModelAndView catchCustomException(IOException ex) { ModelAndView model = new ModelAndView("IOException"); model.addObject("errorMessage", ex.getMessage()); return model; } } |
As you can see, we have annotated two method i.e. catchCustomException and catchIOException with @ExceptionHandler. These methods will handle CustomException and IOException respectively and these exceptions can be thrown by multiple controllers too.
Create view
Modify index.jsp as below
1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>HelloWorld</title> </head> <body> Hello World!! </body> </html> |
Create Custom_Excepion.jsp in /WEB-INF/ folder to handle CustomException exception.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Custom Exception</title> </head> <body> ${errorMessage} </body> </html> |
Create IOException.jsp in /WEB-INF folder as below to handle IOException.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>IO Exception</title> </head> <body> ${errorMessage} </body> </html> |
7) It ‘s time to do maven build.
Right click on project -> Run as -> Maven build
Run the application
10) Lets hit below URL
http://localhost:8080/SpringMVCControllerAdviceExample/helloworld/hello
As you can see, it is working fine with above URL.
Now lets hit some URL which will throw exception and exception will be handled by @ExcpetionHandler in @ControllerAdvice class.
When you hit below URL.
http://localhost:8080/SpringMVCControllerAdviceExample/helloworld/CustomException
As you can see, when you hit above URL , CustomException is thrown and handled by catchCustomException method in @ControllerAdvice class.
When you hit below URL.
http://localhost:8080/SpringMVCControllerAdviceExample/helloworld/IOException