com.huawei.openstack4j.openstack.common.functions.OneOrNull Maven / Gradle / Ivy
/*******************************************************************************
* Copyright 2016 ContainX and OpenStack4j
*
* 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.huawei.openstack4j.openstack.common.functions;
import java.util.List;
import com.google.common.base.Function;
/**
* A Function which returns one entry from a List or null
* @author Jeremy Unruh
*
* @param The return Type
*/
public class OneOrNull implements Function, T> {
public static OneOrNull create() {
return new OneOrNull();
}
@Override
public T apply(List input) {
if (input != null && input.size() > 0)
return input.get(0);
return null;
}
}