Spring : How To Load Properties File using @Value Annotation

This example shows how to load the properties file values using the @Value annotation. Accessing the property file values in the Spring application involves the following steps:

Add the property file details to spring bean configuration file. You have to use the “classpath” prefix if you want to load the files from the classpath.
Create a properties file in the same name that is configured in the XML file and put it under the classpath folders. In most scenarios, source folders will be by default kept under the classpath.
Use @Value annotation to get the property valye. @Value annotation takes the string parameter which is “key” used in the properties file. This annotation has to be used with variables to inject the value.

Lets look at the following example code:

1. Spring MVC Configurations

spring4-mvc-dispatcher-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:websocket="http://www.springframework.org/schema/websocket"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context
		http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/websocket
        http://www.springframework.org/schema/websocket/spring-websocket-4.0.xsd">

<context:component-scan base-package="com.javabeat.controller" />
<context:property-placeholder location="classpath:application.properties"/>
<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix">
			<value>/WEB-INF/jsp/</value>
		</property>
		<property name="suffix">
			<value>.jsp</value>
		</property>
	</bean>

</beans>

2. Application Properties File

application.properties

msg=Spring Application Properties!!

3. Spring MVC Controller

HelloController.java

package com.javabeat.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
@RequestMapping("/welcome")
public class HelloController {
	@Value("${msg}")
	private String msg;

	@RequestMapping(method = RequestMethod.GET)
	public String printWelcome(ModelMap model) {
		model.addAttribute("msg", this.msg);
		return "hello";

	}

}

4. Views

hello.jsp

<html>
<body>
	Your Message : ${msg}
</body>
</html>

5. Web Deployment Descriptor

web.xml

<?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"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0">
<display-name>Spring MVC 4.0 Web Application</display-name>
	<servlet>
		<servlet-name>spring4-mvc-dispatcher</servlet-name>
		<servlet-class>
			org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet-mapping>
		<servlet-name>spring4-mvc-dispatcher</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
</web-app>

6. Demo

If you run the above example, you would get the below output.