| 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.repository.support; |
| 18 | |
| 19 | import java.util.ArrayList; |
| 20 | import java.util.Iterator; |
| 21 | import java.util.List; |
| 22 | |
| 23 | import org.springframework.batch.core.BatchStatus; |
| 24 | import org.springframework.batch.core.Job; |
| 25 | import org.springframework.batch.core.JobExecution; |
| 26 | import org.springframework.batch.core.JobInstance; |
| 27 | import org.springframework.batch.core.JobParameters; |
| 28 | import org.springframework.batch.core.Step; |
| 29 | import org.springframework.batch.core.StepExecution; |
| 30 | import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException; |
| 31 | import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException; |
| 32 | import org.springframework.batch.core.repository.JobRepository; |
| 33 | import org.springframework.batch.core.repository.JobRestartException; |
| 34 | import org.springframework.batch.core.repository.dao.JobExecutionDao; |
| 35 | import org.springframework.batch.core.repository.dao.JobInstanceDao; |
| 36 | import org.springframework.batch.core.repository.dao.StepExecutionDao; |
| 37 | import org.springframework.transaction.annotation.Isolation; |
| 38 | import org.springframework.util.Assert; |
| 39 | |
| 40 | /** |
| 41 | * |
| 42 | * <p> |
| 43 | * Implementation of {@link JobRepository} that stores JobInstances, |
| 44 | * JobExecutions, and StepExecutions using the injected DAOs. |
| 45 | * <p> |
| 46 | * |
| 47 | * @author Lucas Ward |
| 48 | * @author Dave Syer |
| 49 | * @author Robert Kasanicky |
| 50 | * |
| 51 | * @see JobRepository |
| 52 | * @see JobInstanceDao |
| 53 | * @see JobExecutionDao |
| 54 | * @see StepExecutionDao |
| 55 | * |
| 56 | */ |
| 57 | public class SimpleJobRepository implements JobRepository { |
| 58 | |
| 59 | private JobInstanceDao jobInstanceDao; |
| 60 | |
| 61 | private JobExecutionDao jobExecutionDao; |
| 62 | |
| 63 | private StepExecutionDao stepExecutionDao; |
| 64 | |
| 65 | /** |
| 66 | * Provide default constructor with low visibility in case user wants to use |
| 67 | * use aop:proxy-target-class="true" for transaction interceptor. |
| 68 | */ |
| 69 | SimpleJobRepository() { |
| 70 | } |
| 71 | |
| 72 | public SimpleJobRepository(JobInstanceDao jobInstanceDao, JobExecutionDao jobExecutionDao, |
| 73 | StepExecutionDao stepExecutionDao) { |
| 74 | super(); |
| 75 | this.jobInstanceDao = jobInstanceDao; |
| 76 | this.jobExecutionDao = jobExecutionDao; |
| 77 | this.stepExecutionDao = stepExecutionDao; |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * <p> |
| 82 | * Create a {@link JobExecution} based on the passed in {@link Job} and |
| 83 | * {@link JobParameters}. However, unique identification of a job can only |
| 84 | * come from the database, and therefore must come from JobDao by either |
| 85 | * creating a new job instance or finding an existing one, which will ensure |
| 86 | * that the id of the job instance is populated with the correct value. |
| 87 | * </p> |
| 88 | * |
| 89 | * <p> |
| 90 | * There are two ways in which the method determines if a job should be |
| 91 | * created or an existing one should be returned. The first is |
| 92 | * restartability. The {@link Job} restartable property will be checked |
| 93 | * first. If it is false, a new job will be created, regardless of whether |
| 94 | * or not one exists. If it is true, the {@link JobInstanceDao} will be |
| 95 | * checked to determine if the job already exists, if it does, it's steps |
| 96 | * will be populated (there must be at least 1) and a new |
| 97 | * {@link JobExecution} will be returned. If no job instance is found, a new |
| 98 | * one will be created. |
| 99 | * </p> |
| 100 | * |
| 101 | * <p> |
| 102 | * A check is made to see if any job executions are already running, and an |
| 103 | * exception will be thrown if one is detected. To detect a running job |
| 104 | * execution we use the {@link JobExecutionDao}: |
| 105 | * <ol> |
| 106 | * <li>First we find all jobs which match the given {@link JobParameters} |
| 107 | * and job name</li> |
| 108 | * <li>What happens then depends on how many existing job instances we |
| 109 | * find: |
| 110 | * <ul> |
| 111 | * <li>If there are none, or the {@link Job} is marked restartable, then we |
| 112 | * create a new {@link JobInstance}</li> |
| 113 | * <li>If there is more than one and the {@link Job} is not marked as |
| 114 | * restartable, it is an error. This could be caused by a job whose |
| 115 | * restartable flag has changed to be more strict (true not false) |
| 116 | * <em>after</em> it has been executed at least once.</li> |
| 117 | * <li>If there is precisely one existing {@link JobInstance} then we check |
| 118 | * the {@link JobExecution} instances for that job, and if any of them tells |
| 119 | * us it is running (see {@link JobExecution#isRunning()}) then it is an |
| 120 | * error.</li> |
| 121 | * </ul> |
| 122 | * </li> |
| 123 | * </ol> |
| 124 | * If this method is run in a transaction (as it normally would be) with |
| 125 | * isolation level at {@link Isolation#REPEATABLE_READ} or better, then this |
| 126 | * method should block if another transaction is already executing it (for |
| 127 | * the same {@link JobParameters} and job name). The first transaction to |
| 128 | * complete in this scenario obtains a valid {@link JobExecution}, and |
| 129 | * others throw {@link JobExecutionAlreadyRunningException} (or timeout). |
| 130 | * There are no such guarantees if the {@link JobInstanceDao} and |
| 131 | * {@link JobExecutionDao} do not respect the transaction isolation levels |
| 132 | * (e.g. if using a non-relational data-store, or if the platform does not |
| 133 | * support the higher isolation levels). |
| 134 | * </p> |
| 135 | * |
| 136 | * @see JobRepository#createJobExecution(Job, JobParameters) |
| 137 | * |
| 138 | */ |
| 139 | public JobExecution createJobExecution(Job job, JobParameters jobParameters) |
| 140 | throws JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException { |
| 141 | |
| 142 | Assert.notNull(job, "Job must not be null."); |
| 143 | Assert.notNull(jobParameters, "JobParameters must not be null."); |
| 144 | |
| 145 | /* |
| 146 | * Find all jobs matching the runtime information. |
| 147 | * |
| 148 | * If this method is transactional, and the isolation level is |
| 149 | * REPEATABLE_READ or better, another launcher trying to start the same |
| 150 | * job in another thread or process will block until this transaction |
| 151 | * has finished. |
| 152 | */ |
| 153 | |
| 154 | JobInstance jobInstance = jobInstanceDao.getJobInstance(job, jobParameters); |
| 155 | |
| 156 | // existing job instance found |
| 157 | if (jobInstance != null) { |
| 158 | if (!job.isRestartable()) { |
| 159 | throw new JobRestartException("JobInstance already exists and is not restartable"); |
| 160 | } |
| 161 | |
| 162 | List executions = jobExecutionDao.findJobExecutions(jobInstance); |
| 163 | |
| 164 | // check for running executions and find the last started |
| 165 | for (Iterator iterator = executions.iterator(); iterator.hasNext();) { |
| 166 | JobExecution execution = (JobExecution) iterator.next(); |
| 167 | if (execution.isRunning()) { |
| 168 | throw new JobExecutionAlreadyRunningException("A job execution for this job is already running: " |
| 169 | + jobInstance); |
| 170 | } |
| 171 | if (execution.getStatus() == BatchStatus.COMPLETED) { |
| 172 | throw new JobInstanceAlreadyCompleteException( |
| 173 | "A job instance already exists and is complete for parameters=" + jobParameters |
| 174 | + ". If you want to run this job again, change the parameters."); |
| 175 | } |
| 176 | } |
| 177 | } |
| 178 | else { |
| 179 | // no job found, create one |
| 180 | jobInstance = jobInstanceDao.createJobInstance(job, jobParameters); |
| 181 | } |
| 182 | |
| 183 | JobExecution jobExecution = new JobExecution(jobInstance); |
| 184 | |
| 185 | // Save the JobExecution so that it picks up an ID (useful for clients |
| 186 | // monitoring asynchronous executions): |
| 187 | saveOrUpdate(jobExecution); |
| 188 | |
| 189 | return jobExecution; |
| 190 | |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * Save or Update a JobExecution. A JobExecution is considered one |
| 195 | * 'execution' of a particular job. Therefore, it must have it's jobId field |
| 196 | * set before it is passed into this method. It also has it's own unique |
| 197 | * identifier, because it must be updatable separately. If an id isn't found, |
| 198 | * a new JobExecution is created, if one is found, the current row is |
| 199 | * updated. |
| 200 | * |
| 201 | * @param jobExecution to be stored. |
| 202 | * @throws IllegalArgumentException if jobExecution is null. |
| 203 | */ |
| 204 | public void saveOrUpdate(JobExecution jobExecution) { |
| 205 | |
| 206 | Assert.notNull(jobExecution, "JobExecution cannot be null."); |
| 207 | Assert.notNull(jobExecution.getJobId(), "JobExecution must have a Job ID set."); |
| 208 | |
| 209 | if (jobExecution.getId() == null) { |
| 210 | // existing instance |
| 211 | jobExecutionDao.saveJobExecution(jobExecution); |
| 212 | } |
| 213 | else { |
| 214 | // new execution |
| 215 | jobExecutionDao.updateJobExecution(jobExecution); |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | /** |
| 220 | * Save or Update the given StepExecution. If it's id is null, it will be |
| 221 | * saved and an id will be set, otherwise it will be updated. It should be |
| 222 | * noted that assigning an ID randomly will likely cause an exception |
| 223 | * depending on the StepDao implementation. |
| 224 | * |
| 225 | * @param stepExecution to be saved. |
| 226 | * @throws IllegalArgumentException if stepExecution is null. |
| 227 | */ |
| 228 | public void saveOrUpdate(StepExecution stepExecution) { |
| 229 | |
| 230 | Assert.notNull(stepExecution, "StepExecution cannot be null."); |
| 231 | Assert.notNull(stepExecution.getStepName(), "StepExecution's step name cannot be null."); |
| 232 | Assert.notNull(stepExecution.getJobExecutionId(), "StepExecution must belong to persisted JobExecution"); |
| 233 | |
| 234 | if (stepExecution.getId() == null) { |
| 235 | stepExecutionDao.saveStepExecution(stepExecution); |
| 236 | } |
| 237 | else { |
| 238 | // existing execution, update |
| 239 | stepExecutionDao.updateStepExecution(stepExecution); |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | /* |
| 244 | * (non-Javadoc) |
| 245 | * @see org.springframework.batch.core.repository.JobRepository#saveOrUpdateExecutionContext(org.springframework.batch.core.domain.StepExecution) |
| 246 | */ |
| 247 | public void saveOrUpdateExecutionContext(StepExecution stepExecution) { |
| 248 | saveOrUpdate(stepExecution); |
| 249 | stepExecutionDao.saveOrUpdateExecutionContext(stepExecution); |
| 250 | } |
| 251 | |
| 252 | /** |
| 253 | * @return the last execution of the step within given job instance |
| 254 | */ |
| 255 | public StepExecution getLastStepExecution(JobInstance jobInstance, Step step) { |
| 256 | List jobExecutions = jobExecutionDao.findJobExecutions(jobInstance); |
| 257 | List stepExecutions = new ArrayList(jobExecutions.size()); |
| 258 | for (Iterator iterator = jobExecutions.iterator(); iterator.hasNext();) { |
| 259 | JobExecution jobExecution = (JobExecution) iterator.next(); |
| 260 | StepExecution stepExecution = stepExecutionDao.getStepExecution(jobExecution, step); |
| 261 | if (stepExecution != null) { |
| 262 | stepExecutions.add(stepExecution); |
| 263 | } |
| 264 | } |
| 265 | StepExecution latest = null; |
| 266 | for (Iterator iterator = stepExecutions.iterator(); iterator.hasNext();) { |
| 267 | StepExecution stepExecution = (StepExecution) iterator.next(); |
| 268 | if (latest == null) { |
| 269 | latest = stepExecution; |
| 270 | } |
| 271 | if (latest.getStartTime().getTime() < stepExecution.getStartTime().getTime()) { |
| 272 | latest = stepExecution; |
| 273 | } |
| 274 | } |
| 275 | return latest; |
| 276 | } |
| 277 | |
| 278 | /** |
| 279 | * @return number of executions of the step within given job instance |
| 280 | */ |
| 281 | public int getStepExecutionCount(JobInstance jobInstance, Step step) { |
| 282 | int count = 0; |
| 283 | List jobExecutions = jobExecutionDao.findJobExecutions(jobInstance); |
| 284 | for (Iterator iterator = jobExecutions.iterator(); iterator.hasNext();) { |
| 285 | JobExecution jobExecution = (JobExecution) iterator.next(); |
| 286 | if (stepExecutionDao.getStepExecution(jobExecution, step) != null) { |
| 287 | count++; |
| 288 | } |
| 289 | } |
| 290 | return count; |
| 291 | } |
| 292 | |
| 293 | } |