001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.spring.util;
018
019 import java.lang.reflect.InvocationTargetException;
020 import java.lang.reflect.Method;
021 import java.lang.reflect.Modifier;
022 import java.util.Arrays;
023
024 import org.slf4j.Logger;
025 import org.slf4j.LoggerFactory;
026
027 import org.springframework.beans.factory.InitializingBean;
028
029 import static org.apache.camel.util.ObjectHelper.name;
030
031 /**
032 * A simple helper bean for running main classes from within the spring.xml
033 * usually asynchronous in a background thread; which is useful for demos such
034 * as running Swing programs in the same JVM.
035 *
036 * @version
037 */
038 public class MainRunner implements InitializingBean, Runnable {
039 private static final Logger LOG = LoggerFactory.getLogger(MainRunner.class);
040
041 private Class<?> main;
042 private String[] args = {};
043 private boolean asyncRun = true;
044 private long delay;
045
046 public String toString() {
047 return "MainRunner(" + name(main) + " " + Arrays.asList(getArgs()) + ")";
048 }
049
050 public void run() {
051 try {
052 runMethodWithoutCatchingExceptions();
053 } catch (NoSuchMethodException e) {
054 LOG.error("Class: " + name(main) + " does not have a main method: " + e, e);
055 } catch (IllegalAccessException e) {
056 LOG.error("Failed to run: " + this + ". Reason: " + e, e);
057 } catch (InvocationTargetException e) {
058 Throwable throwable = e.getTargetException();
059 LOG.error("Failed to run: " + this + ". Reason: " + throwable, throwable);
060 }
061 }
062
063 public void runMethodWithoutCatchingExceptions() throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
064 if (delay > 0) {
065 try {
066 Thread.sleep(delay);
067 } catch (InterruptedException e) {
068 Thread.currentThread().interrupt();
069 }
070 }
071 Method method = main.getMethod("main", String[].class);
072 if (!Modifier.isStatic(method.getModifiers())) {
073 throw new IllegalArgumentException("The main method is not static!: " + method);
074 }
075 Object[] arguments = {getArgs()};
076 method.invoke(null, arguments);
077 }
078
079 public String[] getArgs() {
080 return args;
081 }
082
083 public void setArgs(String[] args) {
084 this.args = args;
085 }
086
087 public boolean isAsyncRun() {
088 return asyncRun;
089 }
090
091 public void setAsyncRun(boolean asyncRun) {
092 this.asyncRun = asyncRun;
093 }
094
095 public Class<?> getMain() {
096 return main;
097 }
098
099 public void setMain(Class<?> main) {
100 this.main = main;
101 }
102
103 public long getDelay() {
104 return delay;
105 }
106
107 public void setDelay(long delay) {
108 this.delay = delay;
109 }
110
111 public void afterPropertiesSet() throws Exception {
112 if (main == null) {
113 throw new IllegalArgumentException("You must specify a main class!");
114 }
115 if (isAsyncRun()) {
116 Thread thread = new Thread(this, "Thread for: " + this);
117 thread.start();
118 } else {
119 runMethodWithoutCatchingExceptions();
120 }
121 }
122 }