com.googlecode.ehcache.annotations.key.MessageDigestCacheKeyGenerator Maven / Gradle / Ivy
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Provides a simple model for integrating Ehcache in a Spring project via annotations.
/**
* Copyright 2010 Nicholas Blair, Eric Dalquist
*
* 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.googlecode.ehcache.annotations.key;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.apache.commons.codec.binary.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* @author Eric Dalquist
* @version $Revision: 350 $
*/
public class MessageDigestCacheKeyGenerator extends AbstractDeepCacheKeyGenerator {
/**
* Name of the bean this generator is registered under using the default constructor.
*/
public static final String DEFAULT_BEAN_NAME = "com.googlecode.ehcache.annotations.key.MessageDigestCacheKeyGenerator.DEFAULT_BEAN_NAME";
public static final String DEFAULT_ALGORITHM = "SHA-1";
protected static final int DEFAULT_BYTE_BUFFER_SIZE = 64;
protected final Logger logger = LoggerFactory.getLogger(this.getClass());
private final MessageDigest baseMessageDigest;
private boolean cloneNotSupported;
/**
* Uses {@link #DEFAULT_ALGORITHM} for the algorithm
* @see AbstractCacheKeyGenerator#AbstractCacheKeyGenerator()
*/
public MessageDigestCacheKeyGenerator() throws NoSuchAlgorithmException {
this(DEFAULT_ALGORITHM);
}
/**
* @see AbstractCacheKeyGenerator#AbstractCacheKeyGenerator()
*/
public MessageDigestCacheKeyGenerator(String algorithm) throws NoSuchAlgorithmException {
this.baseMessageDigest = MessageDigest.getInstance(algorithm);
}
/**
* Uses {@link #DEFAULT_ALGORITHM} for the algorithm
* @see AbstractCacheKeyGenerator#AbstractCacheKeyGenerator(boolean, boolean)
*/
public MessageDigestCacheKeyGenerator(boolean includeMethod, boolean includeParameterTypes) throws NoSuchAlgorithmException {
this(DEFAULT_ALGORITHM, includeMethod, includeParameterTypes);
}
/**
* @see AbstractCacheKeyGenerator#AbstractCacheKeyGenerator(boolean, boolean)
*/
public MessageDigestCacheKeyGenerator(String algorithm, boolean includeMethod, boolean includeParameterTypes) throws NoSuchAlgorithmException {
super(includeMethod, includeParameterTypes);
this.baseMessageDigest = MessageDigest.getInstance(algorithm);
}
@Override
public MessageDigestOutputStream getGenerator(Object... data) {
final MessageDigest messageDigest = this.getMessageDigest();
return new MessageDigestOutputStream(messageDigest);
}
@Override
public String generateKey(MessageDigestOutputStream generator) {
final MessageDigest messageDigest = generator.getMessageDigest();
final byte[] digest = messageDigest.digest();
return this.encodeHash(digest);
}
/**
* Encode the digested hash bytes as a String
*/
protected String encodeHash(final byte[] digest) {
return Base64.encodeBase64URLSafeString(digest);
}
/**
* Tries to clone the {@link MessageDigest} that was created during construction. If the clone fails
* that is remembered and from that point on new {@link MessageDigest} instances will be created on
* every call.
*
* @return Generates a {@link MessageDigest} to use during a call to {@link #generateKey(Object...)}
*/
protected MessageDigest getMessageDigest() {
if (this.cloneNotSupported) {
final String algorithm = this.baseMessageDigest.getAlgorithm();
try {
return MessageDigest.getInstance(algorithm);
}
catch (NoSuchAlgorithmException e) {
throw new IllegalStateException("MessageDigest algorithm '" + algorithm + "' was supported when " + this.getClass().getSimpleName() + " was created but is not now. This should not be possible.", e);
}
}
try {
return (MessageDigest)this.baseMessageDigest.clone();
}
catch (CloneNotSupportedException e) {
this.cloneNotSupported = true;
this.logger.warn("Could not clone MessageDigest using algorithm '" + this.baseMessageDigest.getAlgorithm() + "'. MessageDigest.getInstance will be used from now on which will be much more expensive.", e);
return this.getMessageDigest();
}
}
@Override
protected void append(MessageDigestOutputStream generator, boolean[] a) {
for (final boolean element : a) {
generator.writeBoolean(element);
}
}
@Override
protected void append(MessageDigestOutputStream generator, byte[] a) {
generator.write(a);
}
@Override
protected void append(MessageDigestOutputStream generator, char[] a) {
for (final char element : a) {
generator.writeChar(element);
}
}
@Override
protected void append(MessageDigestOutputStream generator, double[] a) {
for (final double element : a) {
generator.writeDouble(element);
}
}
@Override
protected void append(MessageDigestOutputStream generator, float[] a) {
for (final float element : a) {
generator.writeFloat(element);
}
}
@Override
protected void append(MessageDigestOutputStream generator, int[] a) {
for (final int element : a) {
generator.writeInt(element);
}
}
@Override
protected void append(MessageDigestOutputStream generator, long[] a) {
for (final long element : a) {
generator.writeLong(element);
}
}
@Override
protected void append(MessageDigestOutputStream generator, short[] a) {
for (final short element : a) {
generator.writeShort(element);
}
}
@Override
protected void appendGraphCycle(MessageDigestOutputStream generator, Object o) {
generator.write(0);
}
@Override
protected void appendNull(MessageDigestOutputStream generator) {
generator.write(0);
}
@Override
protected boolean shouldReflect(Object element) {
return !super.implementsHashCode(element);
}
@Override
protected void append(MessageDigestOutputStream generator, Object e) {
if (e instanceof Class) {
this.append(generator, ((Class)e).getName());
}
else if (e instanceof Enum) {
this.append(generator, ((Enum)e).getClass().getName());
this.append(generator, ((Enum)e).name());
}
else if (e instanceof String) {
generator.writeUTF((String)e);
}
else if (e instanceof Boolean) {
generator.writeBoolean((Boolean)e);
}
else if (e instanceof Byte) {
generator.writeByte((Byte)e);
}
else if (e instanceof Character) {
generator.writeChar((Character)e);
}
else if (e instanceof Double) {
generator.writeDouble((Double)e);
}
else if (e instanceof Float) {
generator.writeFloat((Float)e);
}
else if (e instanceof Integer) {
generator.writeInt((Integer)e);
}
else if (e instanceof Long) {
generator.writeLong((Long)e);
}
else if (e instanceof Short) {
generator.writeShort((Short)e);
}
else {
generator.writeInt(e.hashCode());
}
}
}