parquet.hadoop.metadata.FileMetaData Maven / Gradle / Ivy
/**
* Copyright 2012 Twitter, Inc.
*
* 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 parquet.hadoop.metadata;
import static java.util.Collections.unmodifiableMap;
import static parquet.Preconditions.checkNotNull;
import java.io.Serializable;
import java.util.Map;
import parquet.schema.MessageType;
/**
* File level meta data (Schema, codec, ...)
*
* @author Julien Le Dem
*
*/
public final class FileMetaData implements Serializable {
private static final long serialVersionUID = 1L;
private final MessageType schema;
private final Map keyValueMetaData;
private final String createdBy;
/**
* @param schema the schema for the file
* @param keyValueMetaData the app specific metadata
* @param createdBy the description of the library that created the file
*/
public FileMetaData(MessageType schema, Map keyValueMetaData, String createdBy) {
super();
this.schema = checkNotNull(schema, "schema");
this.keyValueMetaData = unmodifiableMap(checkNotNull(keyValueMetaData, "keyValueMetaData"));
this.createdBy = createdBy;
}
/**
* @return the schema for the file
*/
public MessageType getSchema() {
return schema;
}
@Override
public String toString() {
return "FileMetaData{schema: "+schema+ ", metadata: " + keyValueMetaData + "}";
}
/**
* @return meta data for extensions
*/
public Map getKeyValueMetaData() {
return keyValueMetaData;
}
/**
* @return the description of the library that created the file
*/
public String getCreatedBy() {
return createdBy;
}
}