Java tutorial
/* * 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 brooklyn.util.javalang; 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 brooklyn.util.stream.Streams; public class Serializers { public interface ObjectReplacer { public static final ObjectReplacer NOOP = new ObjectReplacer() { @Override public Object replace(Object toserialize) { return toserialize; } @Override public Object resolve(Object todeserialize) { return todeserialize; } }; public Object replace(Object toserialize); public Object resolve(Object todeserialize); } public static <T> T reconstitute(T object) throws IOException, ClassNotFoundException { return reconstitute(object, ObjectReplacer.NOOP); } public static <T> T reconstitute(T object, ObjectReplacer replacer) throws IOException, ClassNotFoundException { if (object == null) return null; return reconstitute(object, object.getClass().getClassLoader(), replacer); } public static <T> T reconstitute(T object, ClassLoader classLoader) throws IOException, ClassNotFoundException { return reconstitute(object, classLoader, ObjectReplacer.NOOP); } @SuppressWarnings("unchecked") public static <T> T reconstitute(T object, ClassLoader classLoader, final ObjectReplacer replacer) throws IOException, ClassNotFoundException { if (object == null) return null; class ReconstitutingObjectOutputStream extends ObjectOutputStream { public ReconstitutingObjectOutputStream(OutputStream outputStream) throws IOException { super(outputStream); enableReplaceObject(true); } @Override protected Object replaceObject(Object obj) throws IOException { return replacer.replace(obj); } } ; ByteArrayOutputStream baos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ReconstitutingObjectOutputStream(baos); oos.writeObject(object); oos.close(); class ReconstitutingObjectInputStream extends ClassLoaderObjectInputStream { public ReconstitutingObjectInputStream(InputStream inputStream, ClassLoader classLoader) throws IOException { super(inputStream, classLoader); super.enableResolveObject(true); } @Override protected Object resolveObject(Object obj) throws IOException { return replacer.resolve(obj); } } ; ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray()); ReconstitutingObjectInputStream ois = new ReconstitutingObjectInputStream(bais, classLoader); try { return (T) ois.readObject(); } finally { Streams.closeQuietly(ois); } } /** * Follows pattern in org.apache.commons.io.input.ClassLoaderObjectInputStream */ public static class ClassLoaderObjectInputStream extends ObjectInputStream { private final ClassLoader classLoader; public ClassLoaderObjectInputStream(InputStream inputStream, ClassLoader classLoader) throws IOException { super(inputStream); this.classLoader = classLoader; } @Override protected Class<?> resolveClass(ObjectStreamClass objectStreamClass) throws IOException, ClassNotFoundException { Class<?> clazz = Class.forName(objectStreamClass.getName(), false, classLoader); if (clazz != null) { return clazz; } else { return super.resolveClass(objectStreamClass); } } } }