org.apache.hadoop.conf.Reconfigurable Maven / Gradle / Ivy
/**
* 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 org.apache.hadoop.conf;
import java.util.Collection;
/**
* Something whose {@link Configuration} can be changed at run time.
*/
public interface Reconfigurable extends Configurable {
/**
* Change a configuration property on this object to the value specified.
*
* Change a configuration property on this object to the value specified
* and return the previous value that the configuration property was set to
* (or null if it was not previously set). If newVal is null, set the property
* to its default value;
*
* If the property cannot be changed, throw a
* {@link ReconfigurationException}.
*/
void reconfigureProperty(String property, String newVal)
throws ReconfigurationException;
/**
* Return whether a given property is changeable at run time.
*
* If isPropertyReconfigurable returns true for a property,
* then changeConf should not throw an exception when changing
* this property.
*/
boolean isPropertyReconfigurable(String property);
/**
* Return all the properties that can be changed at run time.
*/
Collection getReconfigurableProperties();
}