/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* 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
* "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.util;
import org.apache.hadoop.conf.Configuration;
import parquet.hadoop.BadConfigurationException;
public class ConfigurationUtil {
public static Class<?> getClassFromConfig(Configuration configuration, String configName, Class<?> assignableFrom) {
final String className = configuration.get(configName);
if (className == null) {
return null;
}
try {
final Class<?> foundClass = configuration.getClassByName(className);
if (!assignableFrom.isAssignableFrom(foundClass)) {
throw new BadConfigurationException("class " + className + " set in job conf at "
+ configName + " is not a subclass of " + assignableFrom.getCanonicalName());
}
return foundClass;
} catch (ClassNotFoundException e) {
throw new BadConfigurationException("could not instantiate class " + className + " set in job conf at " + configName, e);
}
}
}