001/* 002 * Copyright 2006-2013 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.batch.core.partition.support; 018 019import java.util.ArrayList; 020import java.util.Collection; 021 022import org.springframework.batch.core.StepExecution; 023import org.springframework.batch.core.explore.JobExplorer; 024import org.springframework.beans.factory.InitializingBean; 025import org.springframework.util.Assert; 026 027/** 028 * Convenience class for aggregating a set of {@link StepExecution} instances 029 * when the input comes from remote steps, so the data need to be refreshed from 030 * the repository. 031 * 032 * @author Dave Syer 033 * @since 2.1 034 */ 035public class RemoteStepExecutionAggregator implements StepExecutionAggregator, InitializingBean { 036 037 private StepExecutionAggregator delegate = new DefaultStepExecutionAggregator(); 038 039 private JobExplorer jobExplorer; 040 041 /** 042 * Create a new instance (useful for configuration purposes). 043 */ 044 public RemoteStepExecutionAggregator() { 045 } 046 047 /** 048 * Create a new instance with a job explorer that can be used to refresh the 049 * data when aggregating. 050 * 051 * @param jobExplorer the {@link JobExplorer} to use 052 */ 053 public RemoteStepExecutionAggregator(JobExplorer jobExplorer) { 054 super(); 055 this.jobExplorer = jobExplorer; 056 } 057 058 /** 059 * @param jobExplorer the jobExplorer to set 060 */ 061 public void setJobExplorer(JobExplorer jobExplorer) { 062 this.jobExplorer = jobExplorer; 063 } 064 065 /** 066 * @param delegate the delegate to set 067 */ 068 public void setDelegate(StepExecutionAggregator delegate) { 069 this.delegate = delegate; 070 } 071 072 /** 073 * @throws Exception if the job explorer is not provided 074 */ 075 @Override 076 public void afterPropertiesSet() throws Exception { 077 Assert.state(jobExplorer != null, "A JobExplorer must be provided"); 078 } 079 080 /** 081 * Aggregates the input executions into the result {@link StepExecution} 082 * delegating to the delegate aggregator once the input has been refreshed 083 * from the {@link JobExplorer}. 084 * 085 * @see StepExecutionAggregator #aggregate(StepExecution, Collection) 086 */ 087 @Override 088 public void aggregate(StepExecution result, Collection<StepExecution> executions) { 089 Assert.notNull(result, "To aggregate into a result it must be non-null."); 090 if (executions == null) { 091 return; 092 } 093 Collection<StepExecution> updates = new ArrayList<StepExecution>(); 094 for (StepExecution stepExecution : executions) { 095 Long id = stepExecution.getId(); 096 Assert.state(id != null, "StepExecution has null id. It must be saved first: " + stepExecution); 097 StepExecution update = jobExplorer.getStepExecution(stepExecution.getJobExecutionId(), id); 098 Assert.state(update != null, "Could not reload StepExecution from JobRepository: " + stepExecution); 099 updates.add(update); 100 } 101 delegate.aggregate(result, updates); 102 } 103 104}