Configuration
In our previous example, we still use a servlet-context.xml file. In this example, we get rid of it using the @EnableWebMvc annotation.The web.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<context-param>
<param-name>contextClass</param-name>
<param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
</context-param>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>com.jverstry.Configuration</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>MyServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value></param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>MyServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file></welcome-file>
</welcome-file-list>
</web-app>
The Java configuration class:
@EnableWebMvc
@Configuration
@ComponentScan(basePackages = "com.jverstry")
public class WebConfig extends WebMvcConfigurerAdapter {
@Bean
public ViewResolver getViewResolver() {
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("WEB-INF/pages/");
resolver.setSuffix(".jsp");
return resolver;
}
}
JSP pages
We have two JSP pages in the WEB-INF/pages/ directory.index.jsp
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Welcome !!!</title>
</head>
<body>
<h1>
Welcome To Spring MVC With Annotations !!!
</h1>
</body>
</html>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Get Time !!!</title>
</head>
<body>
The time in milliseconds is: <c:out value="${TimeIs}" /> !
</body>
</html>
Controller & Service
Our controller:@Controller
public class MyController {
private MyService myService;
@Autowired
public void setMyService(MyService myService) {
this.myService = myService;
}
@RequestMapping(value = "/")
public String home() {
return "index";
}
@RequestMapping(value = "/getTime")
public String helloWorld(Model model) {
model.addAttribute("TimeIs", myService.getCurrentTimeInMilliseconds());
return "getTime";
}
}
Our service and implementation:
public interface MyService {
long getCurrentTimeInMilliseconds();
}
public class MyServiceImpl implements MyService {
@Override
public long getCurrentTimeInMilliseconds() {
return System.currentTimeMillis();
}
}
@Configuration
public class MyServicesConfiguration {
private MyService myService = new MyServiceImpl();
@Bean
public MyService getMyService() {
return myService;
}
}
Dependencies
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib-nodep</artifactId>
<version>2.2</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
Running The Example
After compiling the project, one can run it using the maven tomcat:run goal. Then, browse:http://localhost:8383/spring-mvc-with-annotations/getTime
It will display something similar to:
The time in milliseconds is: 1346261454171 !
For the same example with Spring Security, click here • More Spring related posts here.
Hi, I am finding it very good and latest spring mvc examples. But i have little confusion here. You are defining both viewresolver and service bean in WebConfig class, is it good to do this? should not we define them separately? As i have learned the context file in DispatcherServlet should have mvc components of your project and context file in ContextLoaderListener should have services and dao components of your project. Could you please clarify?
ReplyDeleteI wrote my example this way to keep the code compact, but it is not mandatory. If you prefer to create a separate class annotated with @Configuration and define your beans there, that's fine too... It is up to you...
DeleteDo u have any curd example in Spring Framework?
ReplyDeleteYes, see: http://tshikatshikaaa.blogspot.com/2012/08/standalone-hibernate-jpa-in-memory.html
DeleteHi,
ReplyDeleteI am new to Spring and I was trying with your code in my sample application and while running i ran into this issue something like this:
Could not autowire method nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No unique bean of type is defined: expected single matching bean but found 2:(MyServiceImpl, getMyService)
In order to fix it I had to comment out the @bean from the MyServicesConfiguration. Dont know if you faced this issue or why I am facing this issue.
@Configuration
public class MyServicesConfiguration {
private MyService myservice = new MyServiceImpl();
//@Bean
public MyService getMyService(){
return myservice;
}
}