parquet.hadoop.util.ConfigurationUtil 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.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 = Class.forName(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);
}
}
}