Spring loading properties files with ApplicationContextInitializer

Posted on October 1, 2015 by

Spring 3.1 introduced a very convenient hook for customizing the application context with ApplicationContextInitializer. It can be used to set active profiles and register custom property sources.

package com.mytutorial.configuration;

import static org.springframework.core.env.StandardEnvironment.SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME;

import java.io.IOException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.ResourcePropertySource;

public class MyAppApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    public static final String DEFAULT_APPLICATION_PROPERTIES = "myapp-service.properties";

    private static final Logger LOG = LoggerFactory.getLogger(MyAppApplicationContextInitializer.class);

   
    @Override
    public void initialize(final ConfigurableApplicationContext applicationContext) {
        final ConfigurableEnvironment environment = applicationContext.getEnvironment();
        final MutablePropertySources propertySources = environment.getPropertySources();
        propertySources.addAfter(SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, getApplicationProperties(environment));
    }

    /**
     * Loads application properties from the configured resource location.
     */
    protected PropertySource<?> getApplicationProperties(final ConfigurableEnvironment environment) {
        try {
            final Resource propertiesResource = new ClassPathResource(DEFAULT_APPLICATION_PROPERTIES);
            final ResourcePropertySource propertySource = new ResourcePropertySource(propertiesResource);
            LOG.info("Configured application properties from: {}", propertySource);
            return propertySource;
        } catch (final IOException ex) {
            throw new RuntimeException("Unable to load application properties from default location: "
                + DEFAULT_APPLICATION_PROPERTIES, ex);
        }
    }
}

package com.mytutorial.configuration;

import static org.springframework.core.env.StandardEnvironment.SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME;

import java.io.IOException;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.context.ApplicationContextInitializer;

import org.springframework.context.ConfigurableApplicationContext;

import org.springframework.core.env.ConfigurableEnvironment;

import org.springframework.core.env.MutablePropertySources;

import org.springframework.core.env.PropertySource;

import org.springframework.core.io.ClassPathResource;

import org.springframework.core.io.Resource;

import org.springframework.core.io.support.ResourcePropertySource;

public class MyAppApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {

public static final String DEFAULT_APPLICATION_PROPERTIES = "myapp-service.properties";

private static final Logger LOG = LoggerFactory.getLogger(MyAppApplicationContextInitializer.class);

@Override

public void initialize(final ConfigurableApplicationContext applicationContext) {

final ConfigurableEnvironment environment = applicationContext.getEnvironment();

final MutablePropertySources propertySources = environment.getPropertySources();

propertySources.addAfter(SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, getApplicationProperties(environment));

}

/**

* Loads application properties from the configured resource location.

protected PropertySource<?> getApplicationProperties(final ConfigurableEnvironment environment) {

try {

final Resource propertiesResource = new ClassPathResource(DEFAULT_APPLICATION_PROPERTIES);

final ResourcePropertySource propertySource = new ResourcePropertySource(propertiesResource);

LOG.info("Configured application properties from: {}", propertySource);

return propertySource;

} catch (final IOException ex) {

throw new RuntimeException("Unable to load application properties from default location: "

+ DEFAULT_APPLICATION_PROPERTIES, ex);

}

The web.xml can configure the “contextInitializerClasses”.



   //.....
   <servlet>
        <servlet-name>MyApp-endpoint</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextClass</param-name>
            <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
        </init-param>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>com.mytutorial.configuration.MyAppEndpointConfiguration</param-value>
        </init-param>
        <init-param>
            <param-name>contextInitializerClasses</param-name>
            <param-value>com.mytutorial.configuration.MyAppApplicationContextInitializer</param-value>

        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

//.....

<servlet-name>MyApp-endpoint</servlet-name>

<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

<init-param>

<param-name>contextClass</param-name>

<param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>

</init-param>

<init-param>

<param-name>contextConfigLocation</param-name>

<param-value>com.mytutorial.configuration.MyAppEndpointConfiguration</param-value>

</init-param>

<init-param>

<param-name>contextInitializerClasses</param-name>

<param-value>com.mytutorial.configuration.MyAppApplicationContextInitializer</param-value>

</init-param>

<load-on-startup>1</load-on-startup>

</servlet>

It can also be used in JUnit tests as shown below.

package com.mytutorial.configuration;

@ContextConfiguration(
    classes = { MyAppEndpointConfiguration.class },
    initializers = MyAppApplicationContextInitializer.class)
@RunWith(SpringJUnit4ClassRunner.class)
public class CapsEntServiceTest {

   //.....tests
 
}

package com.mytutorial.configuration;

@ContextConfiguration(

classes = { MyAppEndpointConfiguration.class },

initializers = MyAppApplicationContextInitializer.class)

@RunWith(SpringJUnit4ClassRunner.class)

public class CapsEntServiceTest {

//.....tests

}

The contents in this Java-Success are copyrighted and from EmpoweringTech pty ltd. The EmpoweringTech pty ltd has the right to correct or enhance the current content without any prior notice. These are general advice only, and one needs to take his/her own circumstances into consideration. The EmpoweringTech pty ltd will not be held liable for any damages caused or alleged to be caused either directly or indirectly by these materials and resources. Any trademarked names or labels used in this blog remain the property of their respective trademark owners. Links to external sites do not imply endorsement of the linked-to sites. Privacy Policy

Responsive WordPress Theme powered by CyberChimps

Top

300+ Java Interview FAQs

200+ Java Key Areas FAQs

150+ Java Architect FAQs

150+ Java Coding FAQs

80+ Java Code Quality FAQs

300+ Big Data Interview FAQs

Big Data Tutorials

Spring loading properties files with ApplicationContextInitializer

Java developer & architect Q&As

Big Data engineer Q&As

Java developers Q&As

Disclaimer