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/*
* Copyright 2000-2013 Vaadin Ltd.
*
* 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.vaadin.sass.internal.util;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
/**
* Utility for making deep copies (vs. clone()'s shallow copies) of objects.
* Objects are first serialized and then deserialized. Error checking is fairly
* minimal in this implementation. If an object is encountered that cannot be
* serialized (or that references an object that cannot be serialized) an error
* is printed to System.err and null is returned. Depending on your specific
* application, it might make more sense to have copy(...) re-throw the
* exception.
*/
public class DeepCopy {
/**
* Returns a copy of the object, or null if the object cannot be serialized.
*/
public static Object copy(Object orig) {
Object obj = null;
if (!(orig instanceof Clonable)) {
try {
// Write the object out to a byte array
FastByteArrayOutputStream fbos = new FastByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(fbos);
out.writeObject(orig);
out.flush();
out.close();
// Retrieve an input stream from the byte array and read
// a copy of the object back in.
ObjectInputStream in = new ObjectInputStream(
fbos.getInputStream());
obj = in.readObject();
in.close();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException cnfe) {
cnfe.printStackTrace();
}
return obj;
} else {
try {
obj = ((Clonable) orig).clone();
} catch (ClassCastException e2) {
// Can't clone, return obj as null
} catch (CloneNotSupportedException e2) {
// Can't clone, return obj as null
}
return obj;
}
}
public static <T> Collection<T> copy(Collection<T> objects) {
List<T> copies = new LinkedList<T>();
for (T object : objects) {
copies.add((T) copy(object));
}
return copies;
}
}
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