Sometime back I have written a tutorial on how to read config file in tradition way. But what if you want to load it as a Spring MVC framework?
It is most common that you may need to access some of your config.properties values all the time in your Java class. There is a simple way to get it using Spring MVC’s singleton scope.
Kindly take a look at below complete workspace picture.
We need to create 4 files:
- CrunchifySpringExample.java under package
com.crunchify.tutorial - config.properties file under
/refer/config/folder - spring-bean.xml file under
/resourcesfolder - pom.xml file (convert project to Maven project)
Let’s get started:
Step-1
Create Dynamic Web Project called CrunchifyLoadPropertiesSpringMVC
Step-2
Convert project to Maven Project.
This will create pom.xml file and we will add Spring dependancies.
Step-3
Create file CrunchifySpringExample.java
package com.crunchify.tutorial;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Scope;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Component;
/**
*
* @author Crunchify.com
*/
@Component("crunchifySpringExample")
@Scope("singleton")
public class CrunchifySpringExample {
private static boolean springExample;
private static String springTutorial;
private static String url;
@Autowired
public CrunchifySpringExample(@Value("${CRUNCHIFY_URL}") String url, @Value("${SPRING_TUTORIAL}") String springTutorial,
@Value("${IS_THIS_SPRING_EXAMPLE}") boolean springExample) {
CrunchifySpringExample.springExample = springExample;
CrunchifySpringExample.springTutorial = springTutorial;
CrunchifySpringExample.url = url;
}
@SuppressWarnings({ "resource", "unused" })
public static void main(String[] args) {
try {
ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext(new String[] { "spring-bean.xml" });
} catch (Throwable e) {
System.out.println(e);
}
System.out.println("\nLoading Properties from Config File during application startup: \n\nSPRING_TUTORIAL: " + springTutorial);
System.out.println("IS_THIS_SPRING_EXAMPLE: " + springExample);
System.out.println("CRUNCHIFY_URL: " + url);
}
}
Step-4
Here is my pom.xml file.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>CrunchifyLoadPropertiesSpringMVC</groupId>
<artifactId>CrunchifyLoadPropertiesSpringMVC</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>CrunchifyLoadPropertiesSpringMVC</name>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>2.3</version>
<configuration>
<warSourceDirectory>WebContent</warSourceDirectory>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring.version>4.0.2.RELEASE</spring.version>
</properties>
<dependencies>
<!-- Spring base -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- Spring MVC -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.1.1</version>
</dependency>
</dependencies>
</project>
Step-5
If you don’t see “resources” folder. create one.
Step-6
Create config.properties file with below contents.
# Crunchify Properties IS_THIS_SPRING_EXAMPLE=true SPRING_TUTORIAL=CRUNCHIFY_TUTORIAL CRUNCHIFY_URL=https://crunchify.com
Step-7
Content of spring-bean.xml file
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:util="http://www.springframework.org/schema/util" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<util:properties id="nodeProperty"
location="classpath:config/config.properties" />
<context:property-placeholder
properties-ref="nodeProperty" />
<context:component-scan base-package="com.crunchify.tutorial" />
</beans>
Step-8
Now run CrunchifySpringExample.java and you should see result like this.
Step-9
Output
Jul 05, 2014 3:38:52 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@7e3bfb66: startup date [Sat Jul 05 15:38:52 CDT 2014]; root of context hierarchy Jul 05, 2014 3:38:52 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions INFO: Loading XML bean definitions from class path resource [spring-bean.xml] Jul 05, 2014 3:38:52 PM org.springframework.core.io.support.PropertiesLoaderSupport loadProperties INFO: Loading properties file from class path resource [config/config.properties] Loading Properties from Config File during application startup: SPRING_TUTORIAL: CRUNCHIFY_TUTORIAL IS_THIS_SPRING_EXAMPLE: true CRUNCHIFY_URL: https://crunchify.com
Enjoy and Happy Coding..