net.eusashead.spring.gaecache.GaeCacheKey.java Source code

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Here is the source code for net.eusashead.spring.gaecache.GaeCacheKey.java

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package net.eusashead.spring.gaecache;

/*
 * #[license]
 * spring-cache-gae
 * %%
 * Copyright (C) 2013 Eusa's Head
 * %%
 * 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.
 * %[license]
 */

import java.util.Arrays;

import org.springframework.util.Assert;

/**
 * A cache key for {@link GaeCache}
 * that comprises of an array of 
 * {@link ArgumentHash} values of the 
 * method arguments for the cached
 * method call.
 * 
 * @author patrickvk
 *
 */
public class GaeCacheKey {

    /**
     * Cache key is composed of an array of Hash values
     */
    private final ArgumentHash[] hashes;

    public GaeCacheKey(ArgumentHash arg) {
        this(new ArgumentHash[] { arg });
    }

    public GaeCacheKey(ArgumentHash[] args) {
        Assert.notNull(args);
        Assert.notEmpty(args);
        Assert.noNullElements(args);
        this.hashes = args;
    }

    /**
     * Return dash-separated
     * hash values based on the 
     * internal {@link ArgumentHash} array
     * @return
     */
    public String hashValue() {
        StringBuilder b = new StringBuilder();
        for (int i = 0; i < hashes.length; i++) {
            ArgumentHash hash = hashes[i];
            if (hash == null) {
                b.append(ArgumentHash.NULL_HASH);
            } else {
                b.append(hash.hashValue());
            }
            if (i < hashes.length - 1) {
                b.append("-");
            }
        }
        return b.toString();
    }

    /**
     * Human-readable representation
     * of un-hashed raw values of the
     * underlying {@link ArgumentHash} array
     * 
     * @return
     */
    public String rawValue() {
        StringBuilder b = new StringBuilder();
        for (int i = 0; i < hashes.length; i++) {
            ArgumentHash hash = hashes[i];
            if (hash == null) {
                b.append("null");
            } else {
                b.append(hash.rawValue());
            }
            if (i < hashes.length - 1) {
                b.append(",");
            }
        }
        return b.toString();
    }

    @Override
    public String toString() {
        return hashValue();
    }

    public static GaeCacheKey create(String raw) {
        return (raw != null ? new GaeCacheKey(new ArgumentHash(raw)) : new GaeCacheKey(new ArgumentHash()));
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + Arrays.hashCode(hashes);
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        GaeCacheKey other = (GaeCacheKey) obj;
        if (!Arrays.equals(hashes, other.hashes))
            return false;
        return true;
    }

}