/*
* 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.nifi.lookup;
import java.util.Optional;
import org.apache.nifi.controller.ControllerService;
public interface LookupService<T> extends ControllerService {
/**
* Looks up a value that corresponds to the given key
*
* @param key the key to lookup
* @return a value that corresponds to the given key
*
* @throws LookupFailureException if unable to lookup a value for the given key
*/
Optional<T> lookup(String key) throws LookupFailureException;
/**
* @return the Class that represents the type of value that will be returned by {@link #lookup(String)}
*/
Class<?> getValueType();
}