com.metamx.common.guava.DefaultingHashMap Maven / Gradle / Ivy
/*
* Copyright 2011,2012 Metamarkets Group 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 com.metamx.common.guava;
import com.google.common.base.Supplier;
import java.util.HashMap;
/**
*/
public class DefaultingHashMap extends HashMap
{
private final Supplier supplier;
public DefaultingHashMap(
Supplier supplier
)
{
this.supplier = supplier;
}
@Override
public V get(Object o)
{
V retVal = super.get(o);
if (retVal == null) {
retVal = supplier.get();
super.put((K) o, retVal);
}
return retVal;
}
}