| 1 | /* |
| 2 | * Copyright 2006-2013 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 | package org.springframework.batch.core.configuration.support; |
| 17 | |
| 18 | import java.util.ArrayList; |
| 19 | import java.util.Collection; |
| 20 | import java.util.HashSet; |
| 21 | import java.util.Map; |
| 22 | import java.util.concurrent.ConcurrentHashMap; |
| 23 | |
| 24 | import org.apache.commons.logging.Log; |
| 25 | import org.apache.commons.logging.LogFactory; |
| 26 | import org.springframework.batch.core.Job; |
| 27 | import org.springframework.batch.core.Step; |
| 28 | import org.springframework.batch.core.configuration.DuplicateJobException; |
| 29 | import org.springframework.batch.core.configuration.JobFactory; |
| 30 | import org.springframework.batch.core.configuration.JobRegistry; |
| 31 | import org.springframework.batch.core.configuration.StepRegistry; |
| 32 | import org.springframework.batch.core.launch.NoSuchJobException; |
| 33 | import org.springframework.batch.core.step.StepLocator; |
| 34 | import org.springframework.beans.factory.InitializingBean; |
| 35 | import org.springframework.context.ApplicationContext; |
| 36 | import org.springframework.context.ConfigurableApplicationContext; |
| 37 | import org.springframework.util.Assert; |
| 38 | |
| 39 | /** |
| 40 | * Default implementation of {@link JobLoader}. Uses a {@link JobRegistry} to |
| 41 | * manage a population of loaded jobs and clears them up when asked. An optional |
| 42 | * {@link StepRegistry} might also be set to register the step(s) available for |
| 43 | * each registered job. |
| 44 | * |
| 45 | * @author Dave Syer |
| 46 | * @author Stephane Nicoll |
| 47 | */ |
| 48 | public class DefaultJobLoader implements JobLoader, InitializingBean { |
| 49 | |
| 50 | private static Log logger = LogFactory.getLog(DefaultJobLoader.class); |
| 51 | |
| 52 | private JobRegistry jobRegistry; |
| 53 | private StepRegistry stepRegistry; |
| 54 | |
| 55 | private Map<ApplicationContextFactory, ConfigurableApplicationContext> contexts = new ConcurrentHashMap<ApplicationContextFactory, ConfigurableApplicationContext>(); |
| 56 | |
| 57 | private Map<ConfigurableApplicationContext, Collection<String>> contextToJobNames = new ConcurrentHashMap<ConfigurableApplicationContext, Collection<String>>(); |
| 58 | |
| 59 | /** |
| 60 | * Default constructor useful for declarative configuration. |
| 61 | */ |
| 62 | public DefaultJobLoader() { |
| 63 | this(null, null); |
| 64 | } |
| 65 | |
| 66 | /** |
| 67 | * Creates a job loader with the job registry provided. |
| 68 | * |
| 69 | * @param jobRegistry a {@link JobRegistry} |
| 70 | */ |
| 71 | public DefaultJobLoader(JobRegistry jobRegistry) { |
| 72 | this(jobRegistry, null); |
| 73 | } |
| 74 | |
| 75 | /** |
| 76 | * Creates a job loader with the job and step registries provided. |
| 77 | * |
| 78 | * @param jobRegistry a {@link JobRegistry} |
| 79 | * @param stepRegistry a {@link StepRegistry} |
| 80 | */ |
| 81 | public DefaultJobLoader(JobRegistry jobRegistry, StepRegistry stepRegistry) { |
| 82 | this.jobRegistry = jobRegistry; |
| 83 | this.stepRegistry = stepRegistry; |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * The {@link JobRegistry} to use for jobs created. |
| 88 | * |
| 89 | * @param jobRegistry the job registry |
| 90 | */ |
| 91 | public void setJobRegistry(JobRegistry jobRegistry) { |
| 92 | this.jobRegistry = jobRegistry; |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * The {@link StepRegistry} to use for the steps of created jobs. |
| 97 | * |
| 98 | * @param stepRegistry the step registry |
| 99 | */ |
| 100 | public void setStepRegistry(StepRegistry stepRegistry) { |
| 101 | this.stepRegistry = stepRegistry; |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * Unregister all the jobs and close all the contexts created by this |
| 106 | * loader. |
| 107 | * |
| 108 | * @see JobLoader#clear() |
| 109 | */ |
| 110 | @Override |
| 111 | public void clear() { |
| 112 | for (ConfigurableApplicationContext context : contexts.values()) { |
| 113 | if (context.isActive()) { |
| 114 | context.close(); |
| 115 | } |
| 116 | } |
| 117 | for (String jobName : jobRegistry.getJobNames()) { |
| 118 | doUnregister(jobName); |
| 119 | } |
| 120 | contexts.clear(); |
| 121 | } |
| 122 | |
| 123 | @Override |
| 124 | public Collection<Job> reload(ApplicationContextFactory factory) { |
| 125 | |
| 126 | // If the same factory is loaded twice the context can be closed |
| 127 | if (contexts.containsKey(factory)) { |
| 128 | ConfigurableApplicationContext context = contexts.get(factory); |
| 129 | for (String name : contextToJobNames.get(context)) { |
| 130 | logger.debug("Unregistering job: " + name + " from context: " + context.getDisplayName()); |
| 131 | doUnregister(name); |
| 132 | } |
| 133 | context.close(); |
| 134 | } |
| 135 | |
| 136 | try { |
| 137 | return doLoad(factory, true); |
| 138 | } |
| 139 | catch (DuplicateJobException e) { |
| 140 | throw new IllegalStateException("Found duplicate job in reload (it should have been unregistered " |
| 141 | + "if it was previously registered in this loader)", e); |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | @Override |
| 146 | public Collection<Job> load(ApplicationContextFactory factory) throws DuplicateJobException { |
| 147 | return doLoad(factory, false); |
| 148 | } |
| 149 | |
| 150 | private Collection<Job> doLoad(ApplicationContextFactory factory, boolean unregister) throws DuplicateJobException { |
| 151 | |
| 152 | Collection<String> jobNamesBefore = jobRegistry.getJobNames(); |
| 153 | ConfigurableApplicationContext context = factory.createApplicationContext(); |
| 154 | Collection<String> jobNamesAfter = jobRegistry.getJobNames(); |
| 155 | // Try to detect auto-registration (e.g. through a bean post processor) |
| 156 | boolean autoRegistrationDetected = jobNamesAfter.size() > jobNamesBefore.size(); |
| 157 | |
| 158 | Collection<String> jobsRegistered = new HashSet<String>(); |
| 159 | if (autoRegistrationDetected) { |
| 160 | for (String name : jobNamesAfter) { |
| 161 | if (!jobNamesBefore.contains(name)) { |
| 162 | jobsRegistered.add(name); |
| 163 | } |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | contexts.put(factory, context); |
| 168 | String[] names = context.getBeanNamesForType(Job.class); |
| 169 | |
| 170 | for (String name : names) { |
| 171 | |
| 172 | if (!autoRegistrationDetected) { |
| 173 | |
| 174 | Job job = (Job) context.getBean(name); |
| 175 | String jobName = job.getName(); |
| 176 | |
| 177 | // On reload try to unregister first |
| 178 | if (unregister) { |
| 179 | logger.debug("Unregistering job: " + jobName + " from context: " + context.getDisplayName()); |
| 180 | doUnregister(jobName); |
| 181 | } |
| 182 | |
| 183 | logger.debug("Registering job: " + jobName + " from context: " + context.getDisplayName()); |
| 184 | doRegister(context, job); |
| 185 | jobsRegistered.add(jobName); |
| 186 | } |
| 187 | |
| 188 | } |
| 189 | |
| 190 | Collection<Job> result = new ArrayList<Job>(); |
| 191 | for (String name : jobsRegistered) { |
| 192 | try { |
| 193 | result.add(jobRegistry.getJob(name)); |
| 194 | } |
| 195 | catch (NoSuchJobException e) { |
| 196 | // should not happen; |
| 197 | throw new IllegalStateException("Could not retrieve job that was should have been registered", e); |
| 198 | } |
| 199 | |
| 200 | } |
| 201 | |
| 202 | contextToJobNames.put(context, jobsRegistered); |
| 203 | |
| 204 | return result; |
| 205 | |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Returns all the {@link Step} instances defined by the specified {@link StepLocator}. |
| 210 | * <p/> |
| 211 | * The specified <tt>jobApplicationContext</tt> is used to collect additional steps that |
| 212 | * are not exposed by the step locator |
| 213 | * |
| 214 | * @param stepLocator the given step locator |
| 215 | * @param jobApplicationContext the application context of the job |
| 216 | * @return all the {@link Step} defined by the given step locator and context |
| 217 | * @see StepLocator |
| 218 | */ |
| 219 | private Collection<Step> getSteps(final StepLocator stepLocator, final ApplicationContext jobApplicationContext) { |
| 220 | final Collection<String> stepNames = stepLocator.getStepNames(); |
| 221 | final Collection<Step> result = new ArrayList<Step>(); |
| 222 | for (String stepName : stepNames) { |
| 223 | result.add(stepLocator.getStep(stepName)); |
| 224 | } |
| 225 | |
| 226 | // Because some steps are referenced by name, we need to look in the context to see if there |
| 227 | // are more Step instances defined. Right now they are registered as being available in the |
| 228 | // context of the job but we have no idea if they are linked to that Job or not. |
| 229 | @SuppressWarnings("unchecked") |
| 230 | final Map<String, Step> allSteps = jobApplicationContext.getBeansOfType(Step.class); |
| 231 | for (Map.Entry<String, Step> entry : allSteps.entrySet()) { |
| 232 | if (!stepNames.contains(entry.getKey())) { |
| 233 | result.add(entry.getValue()); |
| 234 | } |
| 235 | } |
| 236 | return result; |
| 237 | } |
| 238 | |
| 239 | /** |
| 240 | * Registers the specified {@link Job} defined in the specified {@link ConfigurableApplicationContext}. |
| 241 | * <p/> |
| 242 | * Makes sure to update the {@link StepRegistry} if it is available. |
| 243 | * |
| 244 | * @param context the context in which the job is defined |
| 245 | * @param job the job to register |
| 246 | * @throws DuplicateJobException if that job is already registered |
| 247 | */ |
| 248 | private void doRegister(ConfigurableApplicationContext context, Job job) throws DuplicateJobException { |
| 249 | final JobFactory jobFactory = new ReferenceJobFactory(job); |
| 250 | jobRegistry.register(jobFactory); |
| 251 | |
| 252 | if (stepRegistry != null) { |
| 253 | if (!(job instanceof StepLocator)) { |
| 254 | throw new UnsupportedOperationException("Cannot locate steps from a Job that is not a StepLocator: job=" |
| 255 | + job.getName() + " does not implement StepLocator"); |
| 256 | } |
| 257 | stepRegistry.register(job.getName(), getSteps((StepLocator) job, context)); |
| 258 | } |
| 259 | } |
| 260 | |
| 261 | /** |
| 262 | * Unregisters the job identified by the specified <tt>jobName</tt>. |
| 263 | * |
| 264 | * @param jobName the name of the job to unregister |
| 265 | */ |
| 266 | private void doUnregister(String jobName) { |
| 267 | jobRegistry.unregister(jobName); |
| 268 | if (stepRegistry != null) { |
| 269 | stepRegistry.unregisterStepsFromJob(jobName); |
| 270 | } |
| 271 | |
| 272 | } |
| 273 | |
| 274 | @Override |
| 275 | public void afterPropertiesSet() { |
| 276 | Assert.notNull(jobRegistry, "Job registry could not be null."); |
| 277 | } |
| 278 | } |