001/* 002 * Copyright 2006-2018 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 */ 016package org.springframework.batch.core; 017 018import java.io.UnsupportedEncodingException; 019import java.math.BigInteger; 020import java.security.MessageDigest; 021import java.security.NoSuchAlgorithmException; 022import java.util.ArrayList; 023import java.util.Collections; 024import java.util.List; 025import java.util.Map; 026 027import org.springframework.util.Assert; 028 029/** 030 * Default implementation of the {@link JobKeyGenerator} interface. 031 * This implementation provides a single hash value based on the JobParameters 032 * passed in. Only identifying parameters (per {@link JobParameter#isIdentifying()}) 033 * are used in the calculation of the key. 034 * 035 * @author Michael Minella 036 * @author Mahmoud Ben Hassine 037 * @since 2.2 038 */ 039public class DefaultJobKeyGenerator implements JobKeyGenerator<JobParameters> { 040 041 /** 042 * Generates the job key to be used based on the {@link JobParameters} instance 043 * provided. 044 */ 045 @Override 046 public String generateKey(JobParameters source) { 047 048 Assert.notNull(source, "source must not be null"); 049 Map<String, JobParameter> props = source.getParameters(); 050 StringBuilder stringBuffer = new StringBuilder(); 051 List<String> keys = new ArrayList<String>(props.keySet()); 052 Collections.sort(keys); 053 for (String key : keys) { 054 JobParameter jobParameter = props.get(key); 055 if(jobParameter.isIdentifying()) { 056 String value = jobParameter.getValue()==null ? "" : jobParameter.toString(); 057 stringBuffer.append(key).append("=").append(value).append(";"); 058 } 059 } 060 061 MessageDigest digest; 062 try { 063 digest = MessageDigest.getInstance("MD5"); 064 } catch (NoSuchAlgorithmException e) { 065 throw new IllegalStateException( 066 "MD5 algorithm not available. Fatal (should be in the JDK)."); 067 } 068 069 try { 070 byte[] bytes = digest.digest(stringBuffer.toString().getBytes( 071 "UTF-8")); 072 return String.format("%032x", new BigInteger(1, bytes)); 073 } catch (UnsupportedEncodingException e) { 074 throw new IllegalStateException( 075 "UTF-8 encoding not available. Fatal (should be in the JDK)."); 076 } 077 } 078}