com.netflix.metacat.connector.hive.util.HiveTableUtil Maven / Gradle / Ivy
/*
* Copyright 2017 Netflix, 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 com.netflix.metacat.connector.hive.util;
import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hive.common.JavaUtils;
import org.apache.hadoop.hive.metastore.MetaStoreUtils;
import org.apache.hadoop.hive.metastore.api.Table;
import org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe;
import org.apache.hadoop.hive.serde.serdeConstants;
import org.apache.hadoop.hive.serde2.Deserializer;
import org.apache.hadoop.hive.serde2.SerDeException;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.StructField;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
import java.util.Collections;
import java.util.List;
import java.util.Properties;
/**
* HiveTableUtil.
*
* @author zhenl
* @since 1.0.0
*/
@SuppressWarnings("deprecation")
public final class HiveTableUtil {
private static final String PARQUET_HIVE_SERDE = "parquet.hive.serde.ParquetHiveSerDe";
private HiveTableUtil() {
}
/**
* getTableStructFields.
*
* @param table table
* @return all struct field refs
*/
public static List getTableStructFields(final Table table) {
final Properties schema = MetaStoreUtils.getTableMetadata(table);
final String name = schema.getProperty(serdeConstants.SERIALIZATION_LIB);
if (name == null) {
return Collections.emptyList();
}
final Deserializer deserializer = createDeserializer(getDeserializerClass(name));
try {
deserializer.initialize(new Configuration(false), schema);
} catch (SerDeException e) {
throw new RuntimeException("error initializing deserializer: " + deserializer.getClass().getName());
}
try {
final ObjectInspector inspector = deserializer.getObjectInspector();
Preconditions.checkArgument(inspector.getCategory() == ObjectInspector.Category.STRUCT,
"expected STRUCT: %s", inspector.getCategory());
return ((StructObjectInspector) inspector).getAllStructFieldRefs();
} catch (SerDeException e) {
throw Throwables.propagate(e);
}
}
private static Class getDeserializerClass(final String name) {
// CDH uses different names for Parquet
if (PARQUET_HIVE_SERDE.equals(name)) {
return ParquetHiveSerDe.class;
}
try {
return Class.forName(name, true, JavaUtils.getClassLoader()).asSubclass(Deserializer.class);
} catch (ClassNotFoundException e) {
throw new RuntimeException("deserializer does not exist: " + name);
} catch (ClassCastException e) {
throw new RuntimeException("invalid deserializer class: " + name);
}
}
private static Deserializer createDeserializer(final Class clazz) {
try {
return clazz.getConstructor().newInstance();
} catch (ReflectiveOperationException e) {
throw new RuntimeException("error creating deserializer: " + clazz.getName(), e);
}
}
}