com.hjz.cache.adapt.GuavaCache.java Source code

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Here is the source code for com.hjz.cache.adapt.GuavaCache.java

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/*
 * Copyright 2002-2015 the original author or authors.
 *
 * 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.hjz.cache.adapt;

import com.google.common.cache.LoadingCache;
import com.google.common.util.concurrent.UncheckedExecutionException;
import org.springframework.cache.support.AbstractValueAdaptingCache;
import org.springframework.util.Assert;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;

/**
 * Spring {@link org.springframework.cache.Cache} adapter implementation
 * on top of a Guava {@link com.google.common.cache.Cache} instance.
 *
 * <p>Requires Google Guava 12.0 or higher.
 *
 * @author Juergen Hoeller
 * @author Stephane Nicoll
 * @since 4.0
 */
public class GuavaCache extends AbstractValueAdaptingCache {

    private final String name;

    private final com.google.common.cache.Cache<Object, Object> cache;

    /**
     * Create a {@link GuavaCache} instance with the specified name and the
     * given internal {@link com.google.common.cache.Cache} to use.
     * @param name the name of the cache
     * @param cache the backing Guava Cache instance
     */
    public GuavaCache(String name, com.google.common.cache.Cache<Object, Object> cache) {
        this(name, cache, true);
    }

    /**
     * Create a {@link GuavaCache} instance with the specified name and the
     * given internal {@link com.google.common.cache.Cache} to use.
     * @param name the name of the cache
     * @param cache the backing Guava Cache instance
     * @param allowNullValues whether to accept and convert {@code null}
     * values for this cache
     */
    public GuavaCache(String name, com.google.common.cache.Cache<Object, Object> cache, boolean allowNullValues) {
        super(allowNullValues);
        Assert.notNull(name, "Name must not be null");
        Assert.notNull(cache, "Cache must not be null");
        this.name = name;
        this.cache = cache;
    }

    @Override
    public final String getName() {
        return this.name;
    }

    @Override
    public final com.google.common.cache.Cache<Object, Object> getNativeCache() {
        return this.cache;
    }

    @Override
    public ValueWrapper get(Object key) {
        if (this.cache instanceof LoadingCache) {
            try {
                Object value = ((LoadingCache<Object, Object>) this.cache).get(key);
                return toValueWrapper(value);
            } catch (ExecutionException ex) {
                throw new UncheckedExecutionException(ex.getMessage(), ex);
            }
        }
        return super.get(key);
    }

    public <T> T get(Object key, final Callable<T> valueLoader) {
        try {
            return (T) this.fromStoreValue(this.cache.get(key, new Callable() {
                public Object call() throws Exception {
                    return GuavaCache.this.toStoreValue(valueLoader.call());
                }
            }));
        } catch (ExecutionException var4) {
            throw new ValueRetrievalException(key, valueLoader, var4.getCause());
        } catch (UncheckedExecutionException var5) {
            throw new ValueRetrievalException(key, valueLoader, var5.getCause());
        }
    }

    @Override
    protected Object lookup(Object key) {
        return this.cache.getIfPresent(key);
    }

    @Override
    public void put(Object key, Object value) {
        this.cache.put(key, toStoreValue(value));
    }

    @Override
    public ValueWrapper putIfAbsent(Object key, final Object value) {
        try {
            PutIfAbsentCallable callable = new PutIfAbsentCallable(value);
            Object result = this.cache.get(key, callable);
            return (callable.called ? null : toValueWrapper(result));
        } catch (ExecutionException ex) {
            throw new IllegalStateException(ex);
        }
    }

    @Override
    public void evict(Object key) {
        this.cache.invalidate(key);
    }

    @Override
    public void clear() {
        this.cache.invalidateAll();
    }

    private class PutIfAbsentCallable implements Callable<Object> {

        private final Object value;

        private boolean called;

        public PutIfAbsentCallable(Object value) {
            this.value = value;
        }

        @Override
        public Object call() throws Exception {
            this.called = true;
            return toStoreValue(this.value);
        }
    }

}