propagate EnvironmentChangeEvents to archaius dynamic property listenters

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/archaius/ArchaiusAutoConfiguration.java

@@ -22,15 +22,22 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import javax.annotation.PreDestroy;
 
 import lombok.extern.apachecommons.CommonsLog;
+import org.apache.commons.configuration.AbstractConfiguration;
 import org.apache.commons.configuration.ConfigurationBuilder;
 import org.apache.commons.configuration.EnvironmentConfiguration;
 import org.apache.commons.configuration.SystemConfiguration;
+import org.apache.commons.configuration.event.ConfigurationEvent;
+import org.apache.commons.configuration.event.ConfigurationListener;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.actuate.endpoint.Endpoint;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
+import org.springframework.context.ApplicationListener;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.Environment;
 import org.springframework.util.ReflectionUtils;
 
 import com.netflix.config.ConcurrentCompositeConfiguration;
@@ -85,6 +92,30 @@ public class ArchaiusAutoConfiguration {
 		}
 	}
 
+	@Configuration
+	@ConditionalOnProperty(value = "archaius.propagate.environmentChangedEvent", matchIfMissing = true)
+	@ConditionalOnClass(EnvironmentChangeEvent.class)
+	protected static class PropagateEventsConfiguration implements ApplicationListener<EnvironmentChangeEvent> {
+		@Autowired
+		private Environment env;
+
+		@Override
+		public void onApplicationEvent(EnvironmentChangeEvent event) {
+			AbstractConfiguration manager = ConfigurationManager.getConfigInstance();
+			for (String key : event.getKeys()) {
+				for (ConfigurationListener listener : manager.getConfigurationListeners()) {
+					Object source = event.getSource();
+					// TODO: Handle add vs set vs delete?
+					int type = AbstractConfiguration.EVENT_SET_PROPERTY;
+					String value = env.getProperty(key);
+					boolean beforeUpdate = false;
+					listener.configurationChanged(new ConfigurationEvent(source,
+							type, key, value, beforeUpdate));
+				}
+			}
+		}
+	}
+
 	@SuppressWarnings("deprecation")
 	protected void configureArchaius(ConfigurableEnvironmentConfiguration envConfig) {
 		if (initialized.compareAndSet(false, true)) {

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/archaius/ArchaiusAutoConfigurationTests.java

@@ -16,11 +16,18 @@
 
 package org.springframework.cloud.netflix.archaius;
 
+import com.google.common.collect.Sets;
+import com.netflix.config.ConfigurationManager;
 import org.apache.commons.configuration.AbstractConfiguration;
+import org.apache.commons.configuration.event.ConfigurationEvent;
+import org.apache.commons.configuration.event.ConfigurationListener;
 import org.junit.After;
 import org.junit.Test;
+import org.springframework.boot.test.EnvironmentTestUtils;
+import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
 /**
@@ -29,6 +36,7 @@ import static org.junit.Assert.assertNotNull;
 public class ArchaiusAutoConfigurationTests {
 
 	private AnnotationConfigApplicationContext context;
+	private Object propertyValue;
 
 	@After
 	public void close() {
@@ -46,4 +54,21 @@ public class ArchaiusAutoConfigurationTests {
 		assertNotNull(config.getString("java.io.tmpdir"));
 	}
 
+	@Test
+	public void environmentChangeEventPropagated() {
+		this.context = new AnnotationConfigApplicationContext(
+				ArchaiusAutoConfiguration.class);
+		ConfigurationManager.getConfigInstance().addConfigurationListener(new ConfigurationListener() {
+			@Override
+			public void configurationChanged(ConfigurationEvent event) {
+				if (event.getPropertyName().equals("my.prop")) {
+					propertyValue = event.getPropertyValue();
+				}
+			}
+		});
+		EnvironmentTestUtils.addEnvironment(context, "my.prop=my.newval");
+		context.publishEvent(new EnvironmentChangeEvent(Sets.newHashSet("my.prop")));
+		assertEquals("my.newval", propertyValue);
+	}
+
 }