org.springframework.batch.core.DefaultJobKeyGenerator Maven / Gradle / Ivy
/*
* Copyright 2006-2018 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
*
* https://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;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.springframework.util.Assert;
/**
* Default implementation of the {@link JobKeyGenerator} interface.
* This implementation provides a single hash value based on the JobParameters
* passed in. Only identifying parameters (per {@link JobParameter#isIdentifying()})
* are used in the calculation of the key.
*
* @author Michael Minella
* @author Mahmoud Ben Hassine
* @since 2.2
*/
public class DefaultJobKeyGenerator implements JobKeyGenerator {
/**
* Generates the job key to be used based on the {@link JobParameters} instance
* provided.
*/
@Override
public String generateKey(JobParameters source) {
Assert.notNull(source, "source must not be null");
Map props = source.getParameters();
StringBuilder stringBuffer = new StringBuilder();
List keys = new ArrayList<>(props.keySet());
Collections.sort(keys);
for (String key : keys) {
JobParameter jobParameter = props.get(key);
if(jobParameter.isIdentifying()) {
String value = jobParameter.getValue()==null ? "" : jobParameter.toString();
stringBuffer.append(key).append("=").append(value).append(";");
}
}
MessageDigest digest;
try {
digest = MessageDigest.getInstance("MD5");
} catch (NoSuchAlgorithmException e) {
throw new IllegalStateException(
"MD5 algorithm not available. Fatal (should be in the JDK).");
}
try {
byte[] bytes = digest.digest(stringBuffer.toString().getBytes(
"UTF-8"));
return String.format("%032x", new BigInteger(1, bytes));
} catch (UnsupportedEncodingException e) {
throw new IllegalStateException(
"UTF-8 encoding not available. Fatal (should be in the JDK).");
}
}
}