| 1 | /* |
| 2 | * Copyright 2006-2008 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.launch.support; |
| 17 | |
| 18 | import org.apache.commons.logging.Log; |
| 19 | import org.apache.commons.logging.LogFactory; |
| 20 | import org.springframework.batch.core.Job; |
| 21 | import org.springframework.batch.core.JobExecution; |
| 22 | import org.springframework.batch.core.JobInstance; |
| 23 | import org.springframework.batch.core.JobParameters; |
| 24 | import org.springframework.batch.core.launch.JobLauncher; |
| 25 | import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException; |
| 26 | import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException; |
| 27 | import org.springframework.batch.core.repository.JobRepository; |
| 28 | import org.springframework.batch.core.repository.JobRestartException; |
| 29 | import org.springframework.beans.factory.InitializingBean; |
| 30 | import org.springframework.core.task.SyncTaskExecutor; |
| 31 | import org.springframework.core.task.TaskExecutor; |
| 32 | import org.springframework.util.Assert; |
| 33 | |
| 34 | /** |
| 35 | * Simple implementation of the {@link JobLauncher} interface. The Spring Core |
| 36 | * {@link TaskExecutor} interface is used to launch a {@link Job}. This means |
| 37 | * that the type of executor set is very important. If a |
| 38 | * {@link SyncTaskExecutor} is used, then the job will be processed |
| 39 | * <strong>within the same thread that called the launcher.</strong> Care should |
| 40 | * be taken to ensure any users of this class understand fully whether or not |
| 41 | * the implementation of TaskExecutor used will start tasks synchronously or |
| 42 | * asynchronously. The default setting uses a synchronous task executor. |
| 43 | * |
| 44 | * There is only one required dependency of this Launcher, a |
| 45 | * {@link JobRepository}. The JobRepository is used to obtain a valid |
| 46 | * JobExecution. The Repository must be used because the provided {@link Job} |
| 47 | * could be a restart of an existing {@link JobInstance}, and only the |
| 48 | * Repository can reliably recreate it. |
| 49 | * |
| 50 | * @author Lucas Ward |
| 51 | * @since 1.0 |
| 52 | * @see JobRepository |
| 53 | * @see TaskExecutor |
| 54 | */ |
| 55 | public class SimpleJobLauncher implements JobLauncher, InitializingBean { |
| 56 | |
| 57 | protected static final Log logger = LogFactory.getLog(SimpleJobLauncher.class); |
| 58 | |
| 59 | private JobRepository jobRepository; |
| 60 | |
| 61 | private TaskExecutor taskExecutor; |
| 62 | |
| 63 | /** |
| 64 | * Run the provided job with the given {@link JobParameters}. The |
| 65 | * {@link JobParameters} will be used to determine if this is an execution |
| 66 | * of an existing job instance, or if a new one should be created. |
| 67 | * |
| 68 | * @param job the job to be run. |
| 69 | * @param jobParameters the {@link JobParameters} for this particular |
| 70 | * execution. |
| 71 | * @return JobExecutionAlreadyRunningException if the JobInstance already |
| 72 | * exists and has an execution already running. |
| 73 | * @throws JobRestartException if the execution would be a re-start, but a |
| 74 | * re-start is either not allowed or not needed. |
| 75 | * @throws JobInstanceAlreadyCompleteException if this instance has already |
| 76 | * completed successfully |
| 77 | */ |
| 78 | public JobExecution run(final Job job, final JobParameters jobParameters) |
| 79 | throws JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException { |
| 80 | |
| 81 | Assert.notNull(job, "The Job must not be null."); |
| 82 | Assert.notNull(jobParameters, "The JobParameters must not be null."); |
| 83 | |
| 84 | final JobExecution jobExecution; |
| 85 | JobExecution lastExecution = jobRepository.getLastJobExecution(job.getName(), jobParameters); |
| 86 | if (lastExecution != null) { |
| 87 | if (!job.isRestartable()) { |
| 88 | throw new JobRestartException("JobInstance already exists and is not restartable"); |
| 89 | } |
| 90 | else { |
| 91 | /* |
| 92 | * There is a very small probability that a non-restartable job |
| 93 | * can be restarted, but only if another process or thread |
| 94 | * manages to launch <i>and</i> fail a job execution for this |
| 95 | * instance between the last assertion and the next method |
| 96 | * returning successfully. |
| 97 | */ |
| 98 | jobExecution = jobRepository.createJobExecution(job.getName(), jobParameters); |
| 99 | } |
| 100 | } |
| 101 | else { |
| 102 | jobExecution = jobRepository.createJobExecution(job.getName(), jobParameters); |
| 103 | } |
| 104 | |
| 105 | taskExecutor.execute(new Runnable() { |
| 106 | |
| 107 | public void run() { |
| 108 | try { |
| 109 | logger.info("Job: [" + job + "] launched with the following parameters: [" + jobParameters + "]"); |
| 110 | job.execute(jobExecution); |
| 111 | logger.info("Job: [" + job + "] completed with the following parameters: [" + jobParameters |
| 112 | + "] and the following status: [" + jobExecution.getStatus() + "]"); |
| 113 | } |
| 114 | catch (Throwable t) { |
| 115 | logger.info("Job: [" + job + "] failed unexpectedly and fatally with the following parameters: [" + jobParameters + "]", t); |
| 116 | rethrow(t); |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | private void rethrow(Throwable t) { |
| 121 | if (t instanceof RuntimeException) { |
| 122 | throw (RuntimeException) t; |
| 123 | } |
| 124 | throw new RuntimeException(t); |
| 125 | } |
| 126 | }); |
| 127 | |
| 128 | return jobExecution; |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * Set the JobRepsitory. |
| 133 | * |
| 134 | * @param jobRepository |
| 135 | */ |
| 136 | public void setJobRepository(JobRepository jobRepository) { |
| 137 | this.jobRepository = jobRepository; |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * Set the TaskExecutor. (Optional) |
| 142 | * |
| 143 | * @param taskExecutor |
| 144 | */ |
| 145 | public void setTaskExecutor(TaskExecutor taskExecutor) { |
| 146 | this.taskExecutor = taskExecutor; |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * Ensure the required dependencies of a {@link JobRepository} have been |
| 151 | * set. |
| 152 | */ |
| 153 | public void afterPropertiesSet() throws Exception { |
| 154 | Assert.state(jobRepository != null, "A JobRepository has not been set."); |
| 155 | if (taskExecutor == null) { |
| 156 | logger.info("No TaskExecutor has been set, defaulting to synchronous executor."); |
| 157 | taskExecutor = new SyncTaskExecutor(); |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | } |