/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.commons.lang3;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamClass;
import java.io.OutputStream;
import java.io.Serializable;
/**
* <p>Assists with the serialization process and performs additional functionality based
* on serialization.</p>
* <p>
* <ul>
* <li>Deep clone using serialization
* <li>Serialize managing finally and IOException
* <li>Deserialize managing finally and IOException
* </ul>
*
* <p>This class throws exceptions for invalid {@code null} inputs.
* Each method documents its behaviour in more detail.</p>
*
* <p>#ThreadSafe#</p>
* @since 1.0
* @version $Id: SerializationUtils.java 1153046 2011-08-02 06:57:04Z bayard $
*/
public class SerializationUtils {
/**
* <p>SerializationUtils instances should NOT be constructed in standard programming.
* Instead, the class should be used as {@code SerializationUtils.clone(object)}.</p>
*
* <p>This constructor is public to permit tools that require a JavaBean instance
* to operate.</p>
* @since 2.0
*/
public SerializationUtils() {
super();
}
// Clone
//-----------------------------------------------------------------------
/**
* <p>Deep clone an {@code Object} using serialization.</p>
*
* <p>This is many times slower than writing clone methods by hand
* on all objects in your object graph. However, for complex object
* graphs, or for those that don't support deep cloning this can
* be a simple alternative implementation. Of course all the objects
* must be {@code Serializable}.</p>
*
* @param <T> the type of the object involved
* @param object the {@code Serializable} object to clone
* @return the cloned object
* @throws SerializationException (runtime) if the serialization fails
*/
public static <T extends Serializable> T clone(T object) {
if (object == null) {
return null;
}
byte[] objectData = serialize(object);
ByteArrayInputStream bais = new ByteArrayInputStream(objectData);
ClassLoaderAwareObjectInputStream in = null;
try {
// stream closed in the finally
in = new ClassLoaderAwareObjectInputStream(bais, object.getClass().getClassLoader());
/*
* when we serialize and deserialize an object,
* it is reasonable to assume the deserialized object
* is of the same type as the original serialized object
*/
return (T) in.readObject();
} catch (ClassNotFoundException ex) {
throw new SerializationException("ClassNotFoundException while reading cloned object data", ex);
} catch (IOException ex) {
throw new SerializationException("IOException while reading cloned object data", ex);
} finally {
try {
if (in != null) {
in.close();
}
} catch (IOException ex) {
throw new SerializationException("IOException on closing cloned object data InputStream.", ex);
}
}
}
// Serialize
//-----------------------------------------------------------------------
/**
* <p>Serializes an {@code Object} to the specified stream.</p>
*
* <p>The stream will be closed once the object is written.
* This avoids the need for a finally clause, and maybe also exception
* handling, in the application code.</p>
*
* <p>The stream passed in is not buffered internally within this method.
* This is the responsibility of your application if desired.</p>
*
* @param obj the object to serialize to bytes, may be null
* @param outputStream the stream to write to, must not be null
* @throws IllegalArgumentException if {@code outputStream} is {@code null}
* @throws SerializationException (runtime) if the serialization fails
*/
public static void serialize(Serializable obj, OutputStream outputStream) {
if (outputStream == null) {
throw new IllegalArgumentException("The OutputStream must not be null");
}
ObjectOutputStream out = null;
try {
// stream closed in the finally
out = new ObjectOutputStream(outputStream);
out.writeObject(obj);
} catch (IOException ex) {
throw new SerializationException(ex);
} finally {
try {
if (out != null) {
out.close();
}
} catch (IOException ex) { // NOPMD
// ignore close exception
}
}
}
/**
* <p>Serializes an {@code Object} to a byte array for
* storage/serialization.</p>
*
* @param obj the object to serialize to bytes
* @return a byte[] with the converted Serializable
* @throws SerializationException (runtime) if the serialization fails
*/
public static byte[] serialize(Serializable obj) {
ByteArrayOutputStream baos = new ByteArrayOutputStream(512);
serialize(obj, baos);
return baos.toByteArray();
}
// Deserialize
//-----------------------------------------------------------------------
/**
* <p>Deserializes an {@code Object} from the specified stream.</p>
*
* <p>The stream will be closed once the object is written. This
* avoids the need for a finally clause, and maybe also exception
* handling, in the application code.</p>
*
* <p>The stream passed in is not buffered internally within this method.
* This is the responsibility of your application if desired.</p>
*
* @param inputStream the serialized object input stream, must not be null
* @return the deserialized object
* @throws IllegalArgumentException if {@code inputStream} is {@code null}
* @throws SerializationException (runtime) if the serialization fails
*/
public static Object deserialize(InputStream inputStream) {
if (inputStream == null) {
throw new IllegalArgumentException("The InputStream must not be null");
}
ObjectInputStream in = null;
try {
// stream closed in the finally
in = new ObjectInputStream(inputStream);
return in.readObject();
} catch (ClassNotFoundException ex) {
throw new SerializationException(ex);
} catch (IOException ex) {
throw new SerializationException(ex);
} finally {
try {
if (in != null) {
in.close();
}
} catch (IOException ex) { // NOPMD
// ignore close exception
}
}
}
/**
* <p>Deserializes a single {@code Object} from an array of bytes.</p>
*
* @param objectData the serialized object, must not be null
* @return the deserialized object
* @throws IllegalArgumentException if {@code objectData} is {@code null}
* @throws SerializationException (runtime) if the serialization fails
*/
public static Object deserialize(byte[] objectData) {
if (objectData == null) {
throw new IllegalArgumentException("The byte[] must not be null");
}
ByteArrayInputStream bais = new ByteArrayInputStream(objectData);
return deserialize(bais);
}
/**
* <p>Custom specialization of the standard JDK {@link java.io.ObjectInputStream}
* that uses a custom <code>ClassLoader</code> to resolve a class.
* If the specified <code>ClassLoader</code> is not able to resolve the class,
* the context classloader of the current thread will be used.
* This way, the standard deserialization work also in web-application
* containers and application servers, no matter in which of the
* <code>ClassLoader</code> the particular class that encapsulates
* serialization/deserialization lives. </p>
*
* <p>For more in-depth information about the problem for which this
* class here is a workaround, see the JIRA issue LANG-626. </p>
*/
static class ClassLoaderAwareObjectInputStream extends ObjectInputStream {
private ClassLoader classLoader;
/**
* Constructor.
* @param in The <code>InputStream</code>.
* @param classLoader classloader to use
* @throws IOException if an I/O error occurs while reading stream header.
* @see java.io.ObjectInputStream
*/
public ClassLoaderAwareObjectInputStream(InputStream in, ClassLoader classLoader) throws IOException {
super(in);
this.classLoader = classLoader;
}
/**
* Overriden version that uses the parametrized <code>ClassLoader</code> or the <code>ClassLoader</code>
* of the current <code>Thread</code> to resolve the class.
* @param desc An instance of class <code>ObjectStreamClass</code>.
* @return A <code>Class</code> object corresponding to <code>desc</code>.
* @throws IOException Any of the usual Input/Output exceptions.
* @throws ClassNotFoundException If class of a serialized object cannot be found.
*/
@Override
protected Class<?> resolveClass(ObjectStreamClass desc) throws IOException, ClassNotFoundException {
String name = desc.getName();
try {
return Class.forName(name, false, classLoader);
} catch (ClassNotFoundException ex) {
return Class.forName(name, false, Thread.currentThread().getContextClassLoader());
}
}
}
}
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