src/com/android/providers/media/util/CachedSupplier.java

/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * 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.android.providers.media.util;

import java.util.function.Supplier;

public class CachedSupplier<T> implements Supplier<T> {
    private final Supplier<T> wrapped;
    private volatile T cache;

    public CachedSupplier(Supplier<T> wrapped) {
        this.wrapped = wrapped;
    }

    @Override
    public T get() {
        if (cache == null) {
            cache = wrapped.get();
        }
        return cache;
    }
}