com.github.helenusdriver.persistence.EncryptedObject Maven / Gradle / Ivy
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/*
* Copyright (C) 2015-2015 The Helenus Driver Project 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.github.helenusdriver.persistence;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import com.github.helenusdriver.commons.lang3.SerializationUtils;
/**
* The EncryptedObject class defines a wrapper around an object
* which provides encryption support when the object is serialized.
*
* Note: Decryption is lazily performed on-demand when the contained
* object is accessed for the first time.
*
* @copyright 2015-2015 The Helenus Driver Project Authors
*
* @author The Helenus Driver Project Authors
* @version 1 - Jan 15, 2015 - paouelle - Creation
*
* @param the type of the object wrapped by this encrypted object.
*
* @since 1.0
*/
public class EncryptedObject implements Serializable {
/**
* Holds the serialVersionUID.
*
* @author paouelle
*/
private static final long serialVersionUID = -6109621505397950062L;
/**
* Holds the encrypted object.
*
* @author paouelle
*/
private byte[] blob;
/**
* Holds the decrypted object.
*
* @author paouelle
*/
private transient T object;
/**
* Flag indicating if the object has been encrypted already..
*
* @author paouelle
*/
private transient boolean encrypted;
/**
* Flag indicating if the object has been decrypted and cached into
* {@link #object}.
*
* @author paouelle
*/
private transient boolean decrypted;
/**
* Instantiates a new EncryptedObject object.
*
* @author paouelle
*/
public EncryptedObject() {
this.object = null;
this.encrypted = false;
this.decrypted = true;
}
/**
* Instantiates a new EncryptedObject object.
*
* @author paouelle
*
* @param object the object to encrypt
*/
public EncryptedObject(T object) {
this.object = object;
this.encrypted = false;
this.decrypted = true;
}
/**
* Deserializes this object from the given stream.
*
* @author paouelle
*
* @param in the input stream from which to deserialize this object
* @throws IOException if an error occured during deserialization
* @throws ClassNotFoundException if a class cannot be loaded
*/
private synchronized void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException {
this.blob = (byte[])in.readObject();
// update transient fields
this.encrypted = true;
this.decrypted = false;
this.object = null;
}
/**
* Serializes this object into the given stream.
*
* @author paouelle
*
* @param out the output stream where to serialize this object
* @throws IOException if an error occurred during serialization
*/
private synchronized void writeObject(ObjectOutputStream out) throws IOException {
if (!encrypted) {
// TODO: encrypt the object
this.blob = (object != null) ? SerializationUtils.serializeAndCompress(object) : null;
this.encrypted = true;
}
out.writeObject(blob);
}
/**
* Sets the object to encrypt.
*
* @author paouelle
*
* @param object the object to be encrypted
*/
public synchronized void setObject(T object) {
this.object = object;
this.encrypted = false;
this.decrypted = true;
}
/**
* Gets the referenced object (decrypting it if required)
*
* @author paouelle
*
* @return the decrypted object
*/
@SuppressWarnings("unchecked")
public synchronized T getObject() {
if (decrypted) {
return object;
}
if (!encrypted) {
return null;
}
// go ahead and decrypt it
// TODO: decrypt the object
this.object = (blob != null) ? (T)SerializationUtils.decompressAndDeserialize(blob) : null;
this.decrypted = true;
return object;
}
/**
* {@inheritDoc}
*
* @author paouelle
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "";
}
}