1 | /* |
2 | * Copyright 2006-2007 the original author or authors. |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. |
6 | * You may obtain a copy of the License at |
7 | * |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * |
10 | * Unless required by applicable law or agreed to in writing, software |
11 | * distributed under the License is distributed on an "AS IS" BASIS, |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | * See the License for the specific language governing permissions and |
14 | * limitations under the License. |
15 | */ |
16 | |
17 | package org.springframework.batch.core.configuration.support; |
18 | |
19 | import java.util.ArrayList; |
20 | import java.util.Collection; |
21 | |
22 | import org.springframework.batch.core.Job; |
23 | import org.springframework.batch.core.configuration.DuplicateJobException; |
24 | import org.springframework.batch.core.configuration.JobRegistry; |
25 | import org.springframework.beans.factory.InitializingBean; |
26 | import org.springframework.context.ApplicationContext; |
27 | import org.springframework.context.ApplicationContextAware; |
28 | import org.springframework.context.ApplicationEvent; |
29 | import org.springframework.context.ApplicationListener; |
30 | import org.springframework.context.Lifecycle; |
31 | import org.springframework.context.event.ContextClosedEvent; |
32 | import org.springframework.context.event.ContextRefreshedEvent; |
33 | import org.springframework.core.Ordered; |
34 | import org.springframework.util.Assert; |
35 | |
36 | /** |
37 | * Loads and unloads {@link Job Jobs} when the application context is created and destroyed. Each resource provided is |
38 | * loaded as an application context with the current context as its parent, and then all the jobs from the child context |
39 | * are registered under their bean names. A {@link JobRegistry} is required. |
40 | * |
41 | * @author Lucas Ward |
42 | * @author Dave Syer |
43 | * |
44 | * @since 2.1 |
45 | */ |
46 | public class AutomaticJobRegistrar implements Ordered, Lifecycle, ApplicationListener, ApplicationContextAware, |
47 | InitializingBean { |
48 | |
49 | private Collection<ApplicationContextFactory> applicationContextFactories = new ArrayList<ApplicationContextFactory>(); |
50 | |
51 | private JobLoader jobLoader; |
52 | |
53 | private ApplicationContext applicationContext; |
54 | |
55 | private volatile boolean running = false; |
56 | |
57 | private Object lifecycleMonitor = new Object(); |
58 | |
59 | private int order = Ordered.LOWEST_PRECEDENCE; |
60 | |
61 | /** |
62 | * The enclosing application context, which can be used to check if {@link ApplicationEvent events} come from the |
63 | * expected source. |
64 | * |
65 | * @param applicationContext the enclosing application context if there is one |
66 | * @see ApplicationContextAware#setApplicationContext(ApplicationContext) |
67 | */ |
68 | @Override |
69 | public void setApplicationContext(ApplicationContext applicationContext) { |
70 | this.applicationContext = applicationContext; |
71 | } |
72 | |
73 | /** |
74 | * Add some factories to the set that will be used to load contexts and jobs. |
75 | * |
76 | * @param applicationContextFactory the {@link ApplicationContextFactory} values to use |
77 | */ |
78 | public void addApplicationContextFactory(ApplicationContextFactory applicationContextFactory) { |
79 | if (applicationContextFactory instanceof ApplicationContextAware) { |
80 | ((ApplicationContextAware) applicationContextFactory).setApplicationContext(applicationContext); |
81 | } |
82 | this.applicationContextFactories.add(applicationContextFactory); |
83 | } |
84 | |
85 | /** |
86 | * Add some factories to the set that will be used to load contexts and jobs. |
87 | * |
88 | * @param applicationContextFactories the {@link ApplicationContextFactory} values to use |
89 | */ |
90 | public void setApplicationContextFactories(ApplicationContextFactory[] applicationContextFactories) { |
91 | for (ApplicationContextFactory applicationContextFactory : applicationContextFactories) { |
92 | this.applicationContextFactories.add(applicationContextFactory); |
93 | } |
94 | } |
95 | |
96 | /** |
97 | * The job loader that will be used to load and manage jobs. |
98 | * |
99 | * @param jobLoader the {@link JobLoader} to set |
100 | */ |
101 | public void setJobLoader(JobLoader jobLoader) { |
102 | this.jobLoader = jobLoader; |
103 | } |
104 | |
105 | @Override |
106 | public int getOrder() { |
107 | return order; |
108 | } |
109 | |
110 | /** |
111 | * The order to start up and shutdown. |
112 | * @param order the order (default {@link Ordered#LOWEST_PRECEDENCE}). |
113 | * @see Ordered |
114 | */ |
115 | public void setOrder(int order) { |
116 | this.order = order; |
117 | } |
118 | |
119 | /** |
120 | */ |
121 | @Override |
122 | public void afterPropertiesSet() { |
123 | |
124 | Assert.state(jobLoader != null, "A JobLoader must be provided"); |
125 | |
126 | } |
127 | |
128 | /** |
129 | * Creates all the application contexts required and set up job registry entries with all the instances of |
130 | * {@link Job} found therein. Also closes the contexts when the enclosing context is closed. |
131 | * |
132 | * @see InitializingBean#afterPropertiesSet() |
133 | */ |
134 | @Override |
135 | public final void onApplicationEvent(ApplicationEvent event) { |
136 | // TODO: With Spring 3 a SmartLifecycle is started automatically |
137 | if (event.getSource() == applicationContext) { |
138 | if (event instanceof ContextRefreshedEvent) { |
139 | start(); |
140 | } |
141 | else if (event instanceof ContextClosedEvent) { |
142 | stop(); |
143 | } |
144 | } |
145 | } |
146 | |
147 | /** |
148 | * Delegates to {@link JobLoader#clear()}. |
149 | * |
150 | * @see Lifecycle#stop() |
151 | */ |
152 | @Override |
153 | public void stop() { |
154 | synchronized (this.lifecycleMonitor) { |
155 | jobLoader.clear(); |
156 | running = false; |
157 | } |
158 | } |
159 | |
160 | /** |
161 | * Take all the contexts from the factories provided and pass them to the {@link JobLoader}. |
162 | * |
163 | * @see Lifecycle#start() |
164 | */ |
165 | @Override |
166 | public void start() { |
167 | synchronized (this.lifecycleMonitor) { |
168 | if (running) { |
169 | return; |
170 | } |
171 | for (ApplicationContextFactory factory : applicationContextFactories) { |
172 | try { |
173 | jobLoader.load(factory); |
174 | } |
175 | catch (DuplicateJobException e) { |
176 | throw new IllegalStateException(e); |
177 | } |
178 | } |
179 | running = true; |
180 | } |
181 | } |
182 | |
183 | /** |
184 | * Check if this component has been started. |
185 | * |
186 | * @return true if started successfully and not stopped |
187 | * @see Lifecycle#isRunning() |
188 | */ |
189 | @Override |
190 | public boolean isRunning() { |
191 | synchronized (this.lifecycleMonitor) { |
192 | return running; |
193 | } |
194 | } |
195 | |
196 | } |