org.apache.parquet.hadoop.metadata.StrictKeyValueMetadataMergeStrategy Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
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* to you 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
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* specific language governing permissions and limitations
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*/
package org.apache.parquet.hadoop.metadata;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* Strategy to throw errors if there are multiple values for a given key in metadata.
*/
public class StrictKeyValueMetadataMergeStrategy implements KeyValueMetadataMergeStrategy {
/**
* @param keyValueMetaData the merged app specific metadata
*/
public Map merge(Map> keyValueMetaData) {
Map mergedKeyValues = new HashMap();
for (Map.Entry> entry : keyValueMetaData.entrySet()) {
if (entry.getValue().size() > 1) {
throw new RuntimeException("could not merge metadata: key " + entry.getKey()
+ " has conflicting values: " + entry.getValue());
}
mergedKeyValues.put(entry.getKey(), entry.getValue().iterator().next());
}
return mergedKeyValues;
}
}