org.apache.mina.util.LazyInitializer 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.mina.util;
/**
* An abstract class which provides semantics for an object which will be only
* fully initialized when requested to. It allows to avoid loosing time when
* early initializing unnecessary objects.
*
* @param The value type
*
* @author Apache MINA Project
* @since MINA 2.0.0-M2
*/
public abstract class LazyInitializer {
/**
* The value that results on the {@link #init()} call. If null,
* it means that the value has not been initialized yet.
*/
private V value;
/**
* Initializes the value.
*
* @return the initialized value
*/
public abstract V init();
/**
* @return the value resulting from the initialization.
*/
public V get() {
if (value == null) {
value = init();
}
return value;
}
}