| 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.step.job; |
| 17 | |
| 18 | import org.springframework.batch.core.Job; |
| 19 | import org.springframework.batch.core.JobExecution; |
| 20 | import org.springframework.batch.core.JobParameters; |
| 21 | import org.springframework.batch.core.Step; |
| 22 | import org.springframework.batch.core.StepExecution; |
| 23 | import org.springframework.batch.core.UnexpectedJobExecutionException; |
| 24 | import org.springframework.batch.core.launch.JobLauncher; |
| 25 | import org.springframework.batch.core.step.AbstractStep; |
| 26 | import org.springframework.batch.item.ExecutionContext; |
| 27 | import org.springframework.util.Assert; |
| 28 | |
| 29 | /** |
| 30 | * A {@link Step} that delegates to a {@link Job} to do its work. This is a |
| 31 | * great tool for managing dependencies between jobs, and also to modularise |
| 32 | * complex step logic into something that is testable in isolation. The job is |
| 33 | * executed with parameters that can be extracted from the step execution, hence |
| 34 | * this step can also be usefully used as the worker in a parallel or |
| 35 | * partitioned execution. |
| 36 | * |
| 37 | * @author Dave Syer |
| 38 | * |
| 39 | */ |
| 40 | public class JobStep extends AbstractStep { |
| 41 | |
| 42 | /** |
| 43 | * The key for the job parameters in the step execution context. Needed for |
| 44 | * restarts. |
| 45 | */ |
| 46 | private static final String JOB_PARAMETERS_KEY = JobStep.class.getName() + ".JOB_PARAMETERS"; |
| 47 | |
| 48 | private Job job; |
| 49 | |
| 50 | private JobLauncher jobLauncher; |
| 51 | |
| 52 | private JobParametersExtractor jobParametersExtractor = new DefaultJobParametersExtractor(); |
| 53 | |
| 54 | @Override |
| 55 | public void afterPropertiesSet() throws Exception { |
| 56 | super.afterPropertiesSet(); |
| 57 | Assert.state(jobLauncher != null, "A JobLauncher must be provided"); |
| 58 | Assert.state(job != null, "A Job must be provided"); |
| 59 | } |
| 60 | |
| 61 | /** |
| 62 | * The {@link Job} to delegate to in this step. |
| 63 | * |
| 64 | * @param job a {@link Job} |
| 65 | */ |
| 66 | public void setJob(Job job) { |
| 67 | this.job = job; |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * A {@link JobLauncher} is required to be able to run the enclosed |
| 72 | * {@link Job}. |
| 73 | * |
| 74 | * @param jobLauncher the {@link JobLauncher} to set |
| 75 | */ |
| 76 | public void setJobLauncher(JobLauncher jobLauncher) { |
| 77 | this.jobLauncher = jobLauncher; |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * The {@link JobParametersExtractor} is used to extract |
| 82 | * {@link JobParametersExtractor} from the {@link StepExecution} to run the |
| 83 | * {@link Job}. By default an instance will be provided that simply copies |
| 84 | * the {@link JobParameters} from the parent job. |
| 85 | * |
| 86 | * @param jobParametersExtractor the {@link JobParametersExtractor} to set |
| 87 | */ |
| 88 | public void setJobParametersExtractor(JobParametersExtractor jobParametersExtractor) { |
| 89 | this.jobParametersExtractor = jobParametersExtractor; |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Execute the job provided by delegating to the {@link JobLauncher} to |
| 94 | * prevent duplicate executions. The job parameters will be generated by the |
| 95 | * {@link JobParametersExtractor} provided (if any), otherwise empty. On a |
| 96 | * restart, the job parameters will be the same as the last (failed) |
| 97 | * execution. |
| 98 | * |
| 99 | * @see AbstractStep#doExecute(StepExecution) |
| 100 | */ |
| 101 | @Override |
| 102 | protected void doExecute(StepExecution stepExecution) throws Exception { |
| 103 | |
| 104 | ExecutionContext executionContext = stepExecution.getExecutionContext(); |
| 105 | |
| 106 | JobParameters jobParameters; |
| 107 | if (executionContext.containsKey(JOB_PARAMETERS_KEY)) { |
| 108 | jobParameters = (JobParameters) executionContext.get(JOB_PARAMETERS_KEY); |
| 109 | } |
| 110 | else { |
| 111 | jobParameters = jobParametersExtractor.getJobParameters(job, stepExecution); |
| 112 | executionContext.put(JOB_PARAMETERS_KEY, jobParameters); |
| 113 | } |
| 114 | |
| 115 | JobExecution jobExecution = jobLauncher.run(job, jobParameters); |
| 116 | if (jobExecution.getStatus().isUnsuccessful()) { |
| 117 | // AbstractStep will take care of the step execution status |
| 118 | throw new UnexpectedJobExecutionException("Step failure: the delegate Job failed in JobStep."); |
| 119 | } |
| 120 | |
| 121 | } |
| 122 | |
| 123 | } |