Can I replace a Spring bean definition at runtime?

Here is how I have done it in the past: running services which depend on configuration which can be changed on the fly implement a lifecycle interface: IRefreshable:

public interface IRefreshable {
  // Refresh the service having it apply its new values.
  public void refresh(String filter);

  // The service must decide if it wants a cache refresh based on the refresh message filter.
  public boolean requiresRefresh(String filter);

Controllers (or services) which can modify a piece of configuration broadcast to a JMS topic that the configuration has changed (supplying the name of the configuration object). A message driven bean then invokes the IRefreshable interface contract on all beans which implement IRefreshable.

The nice thing with spring is that you can automatically detect any service in your application context that needs to be refreshed, removing the need to explicitly configure them:

public class MyCacheSynchService implements InitializingBean, ApplicationContextAware {
 public void afterPropertiesSet() throws Exception {
  Map<String, ?> refreshableServices = m_appCtx.getBeansOfType(IRefreshable.class);
  for (Map.Entry<String, ?> entry : refreshableServices.entrySet() ) {
   Object beanRef = entry.getValue();
   if (beanRef instanceof IRefreshable) {

This approach works particularly well in a clustered application where one of many app servers might change the configuration, which all then need to be aware of. If you want to use JMX as the mechanism for triggering the changes, your JMX bean can then broadcast to the JMS topic when any of its attributes are changed.

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