/*
* Copyright 2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.batch.core.jsr.job;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.batch.core.BatchStatus;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.StartLimitExceededException;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.explore.JobExplorer;
import org.springframework.batch.core.job.SimpleStepHandler;
import org.springframework.batch.core.repository.JobRepository;
import org.springframework.batch.core.repository.JobRestartException;
import org.springframework.batch.item.ExecutionContext;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;
/**
* Extends {@link SimpleStepHandler} to apply JSR-352 specific logic for whether to
* start a step.
*
* @author Michael Minella
* @since 3.0
*/
public class JsrStepHandler extends SimpleStepHandler {
private static final Log logger = LogFactory.getLog(JsrStepHandler.class);
private JobExplorer jobExplorer;
/**
* @param jobRepository
*/
public JsrStepHandler(JobRepository jobRepository, JobExplorer jobExplorer) {
super(jobRepository, new ExecutionContext());
this.jobExplorer = jobExplorer;
}
@Override
public void afterPropertiesSet() throws Exception {
super.afterPropertiesSet();
Assert.state(jobExplorer != null, "A JobExplorer must be provided");
}
/**
* Given a step and configuration, return true if the step should start,
* false if it should not, and throw an exception if the job should finish.
* @param lastStepExecution the last step execution
* @param jobExecution
* @param step
*
* @throws StartLimitExceededException if the start limit has been exceeded
* for this step
* @throws JobRestartException if the job is in an inconsistent state from
* an earlier failure
*/
@Override
protected boolean shouldStart(StepExecution lastStepExecution, JobExecution jobExecution, Step step)
throws JobRestartException, StartLimitExceededException {
BatchStatus stepStatus;
String restartStep = null;
if (lastStepExecution == null) {
jobExecution.getExecutionContext().put("batch.startedStep", step.getName());
stepStatus = BatchStatus.STARTING;
}
else {
stepStatus = lastStepExecution.getStatus();
JobExecution lastJobExecution = getLastJobExecution(jobExecution);
if(lastJobExecution.getExecutionContext().containsKey("batch.restartStep")) {
restartStep = lastJobExecution.getExecutionContext().getString("batch.restartStep");
if(CollectionUtils.isEmpty(jobExecution.getStepExecutions()) && lastJobExecution.getStatus() == BatchStatus.STOPPED && StringUtils.hasText(restartStep)) {
if(!restartStep.equals(step.getName()) && !jobExecution.getExecutionContext().containsKey("batch.startedStep")) {
logger.info("Job was stopped and should restart at step " + restartStep + ". The current step is " + step.getName());
return false;
} else {
// Indicates the starting point for execution evaluation per JSR-352
jobExecution.getExecutionContext().put("batch.startedStep", step.getName());
}
}
}
}
if (stepStatus == BatchStatus.UNKNOWN) {
throw new JobRestartException("Cannot restart step from UNKNOWN status. "
+ "The last execution ended with a failure that could not be rolled back, "
+ "so it may be dangerous to proceed. Manual intervention is probably necessary.");
}
if ((stepStatus == BatchStatus.COMPLETED && step.isAllowStartIfComplete() == false)
|| stepStatus == BatchStatus.ABANDONED) {
// step is complete, false should be returned, indicating that the
// step should not be started
logger.info("Step already complete or not restartable, so no action to execute: " + lastStepExecution);
return false;
}
if (getJobRepository().getStepExecutionCount(jobExecution.getJobInstance(), step.getName()) < step.getStartLimit()) {
// step start count is less than start max, return true
return true;
}
else {
// start max has been exceeded, throw an exception.
throw new StartLimitExceededException("Maximum start limit exceeded for step: " + step.getName()
+ "StartMax: " + step.getStartLimit());
}
}
/**
* Since all JSR-352 jobs are run asynchronously, {@link JobRepository#getLastJobExecution(String, org.springframework.batch.core.JobParameters)}
* could return the currently running {@link JobExecution}. To get around this, we use the {@link JobExplorer}
* to get a list of the executions and get the most recent one that is <em>not</em> the currently running
* {@link JobExecution}.
*
* @param jobExecution
* @return the last executed JobExecution.
*/
private JobExecution getLastJobExecution(JobExecution jobExecution) {
List<JobExecution> jobExecutions = jobExplorer.getJobExecutions(jobExecution.getJobInstance());
JobExecution lastJobExecution = null;
for (JobExecution curJobExecution : jobExecutions) {
if(lastJobExecution == null && curJobExecution.getId().longValue() != jobExecution.getId().longValue()) {
lastJobExecution = curJobExecution;
} else if(curJobExecution.getId().longValue() != jobExecution.getId().longValue() && (lastJobExecution == null || curJobExecution.getId().longValue() > lastJobExecution.getId().longValue())) {
lastJobExecution = curJobExecution;
}
}
return lastJobExecution;
}
}