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/*
* 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 com.feilong.lib.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;
import java.util.HashMap;
import java.util.Map;
/**
*
* Assists with the serialization process and performs additional functionality based
* on serialization.
*
*
*
* - Deep clone using serialization
*
- Serialize managing finally and IOException
*
- Deserialize managing finally and IOException
*
*
*
* This class throws exceptions for invalid {@code null} inputs.
* Each method documents its behaviour in more detail.
*
*
*
* #ThreadSafe#
*
*
* @since 1.0
*/
public class SerializationUtils{
// Clone
//-----------------------------------------------------------------------
/**
*
* Deep clone an {@code Object} using serialization.
*
*
*
* 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}.
*
*
* @param
* 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 clone(final T object){
if (object == null){
return null;
}
final byte[] objectData = serialize(object);
final ByteArrayInputStream bais = new ByteArrayInputStream(objectData);
try (ClassLoaderAwareObjectInputStream 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
*/
@SuppressWarnings("unchecked") // see above
final T readObject = (T) in.readObject();
return readObject;
}catch (final ClassNotFoundException ex){
throw new IllegalArgumentException("ClassNotFoundException while reading cloned object data", ex);
}catch (final IOException ex){
throw new IllegalArgumentException("IOException while reading or closing cloned object data", ex);
}
}
// Serialize
//-----------------------------------------------------------------------
/**
*
* Serializes an {@code Object} to the specified stream.
*
*
*
* 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.
*
*
*
* The stream passed in is not buffered internally within this method.
* This is the responsibility of your application if desired.
*
*
* @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(final Serializable obj,final OutputStream outputStream){
Validate.notNull(outputStream, "The OutputStream must not be null");
try (ObjectOutputStream out = new ObjectOutputStream(outputStream)){
out.writeObject(obj);
}catch (final IOException ex){
throw new IllegalArgumentException(ex);
}
}
/**
*
* Serializes an {@code Object} to a byte array for
* storage/serialization.
*
*
* @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(final Serializable obj){
final ByteArrayOutputStream baos = new ByteArrayOutputStream(512);
serialize(obj, baos);
return baos.toByteArray();
}
// Deserialize
//-----------------------------------------------------------------------
/**
*
* Deserializes an {@code Object} from the specified stream.
*
*
*
* 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.
*
*
*
* The stream passed in is not buffered internally within this method. This is the responsibility of your
* application if desired.
*
*
*
* If the call site incorrectly types the return value, a {@link ClassCastException} is thrown from the call site.
* Without Generics in this declaration, the call site must type cast and can cause the same ClassCastException.
* Note that in both cases, the ClassCastException is in the call site, not in this method.
*
*
* @param
* the object type to be deserialized
* @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 T deserialize(final InputStream inputStream){
Validate.notNull(inputStream, "The InputStream must not be null");
try (ObjectInputStream in = new ObjectInputStream(inputStream)){
@SuppressWarnings("unchecked")
final T obj = (T) in.readObject();
return obj;
}catch (final ClassNotFoundException | IOException ex){
throw new IllegalArgumentException(ex);
}
}
/**
*
* Deserializes a single {@code Object} from an array of bytes.
*
*
*
* If the call site incorrectly types the return value, a {@link ClassCastException} is thrown from the call site.
* Without Generics in this declaration, the call site must type cast and can cause the same ClassCastException.
* Note that in both cases, the ClassCastException is in the call site, not in this method.
*
*
* @param
* the object type to be deserialized
* @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 T deserialize(final byte[] objectData){
Validate.notNull(objectData, "The byte[] must not be null");
return deserialize(new ByteArrayInputStream(objectData));
}
/**
*
* Custom specialization of the standard JDK {@link java.io.ObjectInputStream}
* that uses a custom {@code ClassLoader} to resolve a class.
* If the specified {@code ClassLoader} 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} the particular class that encapsulates
* serialization/deserialization lives.
*
*
*
* For more in-depth information about the problem for which this
* class here is a workaround, see the JIRA issue LANG-626.
*
*/
static class ClassLoaderAwareObjectInputStream extends ObjectInputStream{
private static final Map> primitiveTypes = new HashMap<>();
static{
primitiveTypes.put("byte", byte.class);
primitiveTypes.put("short", short.class);
primitiveTypes.put("int", int.class);
primitiveTypes.put("long", long.class);
primitiveTypes.put("float", float.class);
primitiveTypes.put("double", double.class);
primitiveTypes.put("boolean", boolean.class);
primitiveTypes.put("char", char.class);
primitiveTypes.put("void", void.class);
}
private final ClassLoader classLoader;
/**
* Constructor.
*
* @param in
* The {@code InputStream}.
* @param classLoader
* classloader to use
* @throws IOException
* if an I/O error occurs while reading stream header.
* @see java.io.ObjectInputStream
*/
ClassLoaderAwareObjectInputStream(final InputStream in, final ClassLoader classLoader) throws IOException{
super(in);
this.classLoader = classLoader;
}
/**
* Overridden version that uses the parameterized {@code ClassLoader} or the {@code ClassLoader}
* of the current {@code Thread} to resolve the class.
*
* @param desc
* An instance of class {@code ObjectStreamClass}.
* @return A {@code Class} object corresponding to {@code desc}.
* @throws IOException
* Any of the usual Input/Output exceptions.
* @throws ClassNotFoundException
* If class of a serialized object cannot be found.
*/
@Override
protected Class resolveClass(final ObjectStreamClass desc) throws IOException,ClassNotFoundException{
final String name = desc.getName();
try{
return Class.forName(name, false, classLoader);
}catch (final ClassNotFoundException ex){
try{
return Class.forName(name, false, Thread.currentThread().getContextClassLoader());
}catch (final ClassNotFoundException cnfe){
final Class cls = primitiveTypes.get(name);
if (cls != null){
return cls;
}
throw cnfe;
}
}
}
}
}