Programmatically refresh the spring mvc resource bundle

ResourceBundleMessageSource messages are configured in Spring's configuration file as

<bean id="messageSource"
  class="org.springframework.context.support.ResourceBundleMessageSource"
  p:basenames="WEB-INF/strings/appstrings" />

Whenever I changed any message in that properties file I have to restart server.

I want to read these updated messages programatically in my application without restarting server.

How can I read these messages programatically in one of my @Controller while running application.

Solution

Define your ResourceBundle property in applicationContext.xml file like:

<!-- Message Source for appstrings -->
<bean id="messageSource"
    class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
    <property name="basename" value="WEB-INF/strings/appstrings" />

</bean>

In you Java class/controller auto-wire it as:

private ReloadableResourceBundleMessageSource messageSource;

  @Autowired
  public void setMessageSource(MessageSource messageSource) {
    this.messageSource = (ReloadableResourceBundleMessageSource) ((DelegatingMessageSource) messageSource).getParentMessageSource();
  }

Then call clearCache() in any function in that class/controller.

messageSource.clearCache();

I got this exception in controller

ReloadableResourceBundleMessageSource incompatible with org.springframework.context.support.DelegatingMessageSource

When you try to run it through messageSource in your controller, you get NOTHING, empty string. And if you look closely, you will find that you have a DelegatingMessageSource in your messageSource property, with an empty parent source, which means it is EMPTY, i.e. always returns blank.

Here’s the solution for this little challenge: move your messageSource definition from spring-servlet.xml to applicationContext.xml!