SPR-5507 Factored out the Phased interface.

org.springframework.context/src/main/java/org/springframework/context/Phased.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2002-2009 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context;
+
+/**
+ * Interface for objects that may participate in a phased
+ * process such as lifecycle management.
+ * 
+ * @author Mark Fisher
+ * @since 3.0
+ * @see SmartLifecycle
+ */
+public interface Phased {
+
+	/**
+	 * Return the phase value of this object.
+	 */
+	int getPhase();
+
+}

org.springframework.context/src/main/java/org/springframework/context/SmartLifecycle.java

@@ -17,13 +17,41 @@
 package org.springframework.context;
 
 /**
- * An extension of the Lifecycle interface for those beans that require to be
+ * An extension of the Lifecycle interface for those objects that require to be
  * started upon ApplicationContext refresh and/or shutdown in a particular order.
+ * The {@link #isAutoStartup()} return value indicates whether this object should
+ * be started at the time of a context refresh. The callback-accepting
+ * {@link #stop(Runnable)} method is useful for objects that have an asynchronous
+ * shutdown process. Any implementation of this interface <i>must</i> invoke the
+ * callback's run() method upon shutdown completion to avoid unnecessary delays
+ * in the overall ApplicationContext shutdown. 
+ * <p>
+ * This interface extends {@link Phased}, and the {@link #getPhase()} method's
+ * return value indicates the phase within which this Lifecycle component should
+ * be started and stopped. The startup process begins with the <i>lowest</i>
+ * phase value and ends with the <i>highest</i> phase value (Integer.MIN_VALUE
+ * is the lowest possible, and Integer.MAX_VALUE is the highest possible). The
+ * shutdown process will apply the reverse order. Any components with the
+ * same value will be arbitrarily ordered within the same phase.
+ * <p>
+ * Example: if component B depends on component A having already started, then
+ * component A should have a lower phase value than component B. During the
+ * shutdown process, component B would be stopped before component A.
+ * <p>
+ * Any explicit "depends-on" relationship will take precedence over
+ * the phase order such that the dependent bean always starts after its
+ * dependency and always stops before its dependency.
+ * <p>
+ * Any Lifecycle components within the context that do not also implement
+ * SmartLifecycle will be treated as if they have a phase value of 0. That
+ * way a SmartLifecycle implementation may start before those Lifecycle
+ * components if it has a negative phase value, or it may start after
+ * those components if it has a positive phase value.
  * 
  * @author Mark Fisher
  * @since 3.0
  */
-public interface SmartLifecycle extends Lifecycle {
+public interface SmartLifecycle extends Lifecycle, Phased {
 
 	/**
 	 * Return whether this Lifecycle component should be started automatically
@@ -32,30 +60,6 @@ public interface SmartLifecycle extends Lifecycle {
 	 */
 	boolean isAutoStartup();
 
-	/**
-	 * Return the phase within which this Lifecycle component should be started
-	 * and stopped. The startup process begins with the <i>lowest</i> phase
-	 * value and ends with the <i>highest</i> phase value (Integer.MIN_VALUE is
-	 * the lowest possible, and Integer.MAX_VALUE is the highest possible). The
-	 * shutdown process will apply the reverse order. Any components with the
-	 * same value will be arbitrarily ordered within the same phase.
-	 * <p>
-	 * Example: if component B depends on component A having already started, then
-	 * component A should have a lower phase value than component B. During the
-	 * shutdown process, component B would be stopped before component A.
-	 * <p>
-	 * Any Lifecycle components within the context that do not also implement
-	 * SmartLifecycle will be treated as if they have a phase value of 0. That
-	 * way a SmartLifecycle implementation may start before those Lifecycle
-	 * components if it has a negative phase value, or it may start after
-	 * those components if it has a positive phase value.
-	 * <p>
-	 * Any explicit "depends-on" relationship will take precedence over
-	 * the phase order such that the dependent bean always starts after its
-	 * dependency and always stops before its dependency.
-	 */
-	int getPhase();
-
 	/**
 	 * Indicates that a Lifecycle component must stop if it is currently running.
 	 * The provided callback is used by the LifecycleProcessor to support an