CAMEL-6269: Added MainListener to make it easier to do custom logic for the lifecycle of start|stop of the main instance.
Project: http://git-wip-us.apache.org/repos/asf/camel/repo Commit: http://git-wip-us.apache.org/repos/asf/camel/commit/01567ab6 Tree: http://git-wip-us.apache.org/repos/asf/camel/tree/01567ab6 Diff: http://git-wip-us.apache.org/repos/asf/camel/diff/01567ab6 Branch: refs/heads/master Commit: 01567ab644034f30c77dd10e742c23f792cdcaac Parents: 83c56bb Author: Claus Ibsen <davscl...@apache.org> Authored: Wed Mar 25 11:21:56 2015 +0100 Committer: Claus Ibsen <davscl...@apache.org> Committed: Wed Mar 25 11:25:11 2015 +0100 ---------------------------------------------------------------------- .../org/apache/camel/main/MainListener.java | 51 ++++++++++++++++++ .../apache/camel/main/MainListenerSupport.java | 39 ++++++++++++++ .../java/org/apache/camel/main/MainSupport.java | 55 +++++++++++++++++++- .../java/org/apache/camel/main/MainExample.java | 15 ++++++ 4 files changed, 158 insertions(+), 2 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/camel/blob/01567ab6/camel-core/src/main/java/org/apache/camel/main/MainListener.java ---------------------------------------------------------------------- diff --git a/camel-core/src/main/java/org/apache/camel/main/MainListener.java b/camel-core/src/main/java/org/apache/camel/main/MainListener.java new file mode 100644 index 0000000..3de7668 --- /dev/null +++ b/camel-core/src/main/java/org/apache/camel/main/MainListener.java @@ -0,0 +1,51 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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.apache.camel.main; + +/** + * A lifecycle listener to receive callbacks when the main is started and stopped. + */ +public interface MainListener { + + /** + * Callback before the CamelContext(s) is being started. + * + * @param main the main instance + */ + void beforeStart(MainSupport main); + + /** + * Callback after the CamelContext(s) has been started. + * + * @param main the main instance + */ + void afterStart(MainSupport main); + + /** + * Callback before the CamelContext(s) is being stopped. + * + * @param main the main instance + */ + void beforeStop(MainSupport main); + + /** + * Callback after the CamelContext(s) has been stopped. + * + * @param main the main instance + */ + void afterStop(MainSupport main); +} http://git-wip-us.apache.org/repos/asf/camel/blob/01567ab6/camel-core/src/main/java/org/apache/camel/main/MainListenerSupport.java ---------------------------------------------------------------------- diff --git a/camel-core/src/main/java/org/apache/camel/main/MainListenerSupport.java b/camel-core/src/main/java/org/apache/camel/main/MainListenerSupport.java new file mode 100644 index 0000000..6dda55b --- /dev/null +++ b/camel-core/src/main/java/org/apache/camel/main/MainListenerSupport.java @@ -0,0 +1,39 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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.apache.camel.main; + +/** + * A useful base class for {@link org.apache.camel.main.MainListener} implementations. + */ +public class MainListenerSupport implements MainListener { + + public void beforeStart(MainSupport main) { + // noop + } + + public void afterStart(MainSupport main) { + // noop + } + + public void beforeStop(MainSupport main) { + // noop + } + + public void afterStop(MainSupport main) { + // noop + } +} http://git-wip-us.apache.org/repos/asf/camel/blob/01567ab6/camel-core/src/main/java/org/apache/camel/main/MainSupport.java ---------------------------------------------------------------------- diff --git a/camel-core/src/main/java/org/apache/camel/main/MainSupport.java b/camel-core/src/main/java/org/apache/camel/main/MainSupport.java index c328df8..726e0d6 100644 --- a/camel-core/src/main/java/org/apache/camel/main/MainSupport.java +++ b/camel-core/src/main/java/org/apache/camel/main/MainSupport.java @@ -46,6 +46,7 @@ import org.slf4j.LoggerFactory; */ public abstract class MainSupport extends ServiceSupport { protected static final Logger LOG = LoggerFactory.getLogger(MainSupport.class); + protected final List<MainListener> listeners = new ArrayList<MainListener>(); protected final List<Option> options = new ArrayList<Option>(); protected final CountDownLatch latch = new CountDownLatch(1); protected final AtomicBoolean completed = new AtomicBoolean(false); @@ -119,6 +120,7 @@ public abstract class MainSupport extends ServiceSupport { public void run() throws Exception { if (!completed.get()) { // if we have an issue starting then propagate the exception to caller + beforeStart(); start(); try { afterStart(); @@ -126,6 +128,7 @@ public abstract class MainSupport extends ServiceSupport { internalBeforeStop(); beforeStop(); stop(); + afterStop(); } catch (Exception e) { // however while running then just log errors LOG.error("Failed: " + e, e); @@ -143,19 +146,67 @@ public abstract class MainSupport extends ServiceSupport { } /** + * Adds a {@link org.apache.camel.main.MainListener} to receive callbacks when the main is started or stopping + * + * @param listener the listener + */ + public void addMainListener(MainListener listener) { + listeners.add(listener); + } + + /** + * Removes the {@link org.apache.camel.main.MainListener} + * + * @param listener the listener + */ + public void removeMainListener(MainListener listener) { + listeners.remove(listener); + } + + /** + * Callback to run custom logic before CamelContext is being started. + * <p/> + * It is recommended to use {@link org.apache.camel.main.MainListener} instead. + */ + protected void beforeStart() throws Exception { + for (MainListener listener : listeners) { + listener.beforeStart(this); + } + } + + /** * Callback to run custom logic after CamelContext has been started. + * <p/> + * It is recommended to use {@link org.apache.camel.main.MainListener} instead. */ protected void afterStart() throws Exception { - // noop + for (MainListener listener : listeners) { + listener.afterStart(this); + } } /** * Callback to run custom logic before CamelContext is being stopped. + * <p/> + * It is recommended to use {@link org.apache.camel.main.MainListener} instead. */ protected void beforeStop() throws Exception { - // noop + for (MainListener listener : listeners) { + listener.beforeStop(this); + } } + /** + * Callback to run custom logic after CamelContext has been stopped. + * <p/> + * It is recommended to use {@link org.apache.camel.main.MainListener} instead. + */ + protected void afterStop() throws Exception { + for (MainListener listener : listeners) { + listener.afterStop(this); + } + } + private void internalBeforeStop() { try { if (camelTemplate != null) { http://git-wip-us.apache.org/repos/asf/camel/blob/01567ab6/camel-core/src/test/java/org/apache/camel/main/MainExample.java ---------------------------------------------------------------------- diff --git a/camel-core/src/test/java/org/apache/camel/main/MainExample.java b/camel-core/src/test/java/org/apache/camel/main/MainExample.java index 8e30738..df64578 100644 --- a/camel-core/src/test/java/org/apache/camel/main/MainExample.java +++ b/camel-core/src/test/java/org/apache/camel/main/MainExample.java @@ -44,6 +44,8 @@ public class MainExample { main.bind("foo", new MyBean()); // add routes main.addRouteBuilder(new MyRouteBuilder()); + // add event listener + main.addMainListener(new Events()); // run until you terminate the JVM System.out.println("Starting Camel. Use ctrl + c to terminate the JVM.\n"); @@ -68,5 +70,18 @@ public class MainExample { System.out.println("MyBean.calleMe method has been called"); } } + + public static class Events extends MainListenerSupport { + + @Override + public void afterStart(MainSupport main) { + System.out.println("MainExample with Camel is now started!"); + } + + @Override + public void beforeStop(MainSupport main) { + System.out.println("MainExample with Camel is now being stopped!"); + } + } } // END SNIPPET: e1
