001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.lang3; 018 019import java.io.ByteArrayInputStream; 020import java.io.ByteArrayOutputStream; 021import java.io.IOException; 022import java.io.InputStream; 023import java.io.ObjectInputStream; 024import java.io.ObjectOutputStream; 025import java.io.ObjectStreamClass; 026import java.io.OutputStream; 027import java.io.Serializable; 028import java.util.HashMap; 029import java.util.Map; 030 031/** 032 * <p>Assists with the serialization process and performs additional functionality based 033 * on serialization.</p> 034 * 035 * <ul> 036 * <li>Deep clone using serialization 037 * <li>Serialize managing finally and IOException 038 * <li>Deserialize managing finally and IOException 039 * </ul> 040 * 041 * <p>This class throws exceptions for invalid {@code null} inputs. 042 * Each method documents its behaviour in more detail.</p> 043 * 044 * <p>#ThreadSafe#</p> 045 * @since 1.0 046 */ 047public class SerializationUtils { 048 049 /** 050 * <p>SerializationUtils instances should NOT be constructed in standard programming. 051 * Instead, the class should be used as {@code SerializationUtils.clone(object)}.</p> 052 * 053 * <p>This constructor is public to permit tools that require a JavaBean instance 054 * to operate.</p> 055 * @since 2.0 056 */ 057 public SerializationUtils() { 058 super(); 059 } 060 061 // Clone 062 //----------------------------------------------------------------------- 063 /** 064 * <p>Deep clone an {@code Object} using serialization.</p> 065 * 066 * <p>This is many times slower than writing clone methods by hand 067 * on all objects in your object graph. However, for complex object 068 * graphs, or for those that don't support deep cloning this can 069 * be a simple alternative implementation. Of course all the objects 070 * must be {@code Serializable}.</p> 071 * 072 * @param <T> the type of the object involved 073 * @param object the {@code Serializable} object to clone 074 * @return the cloned object 075 * @throws SerializationException (runtime) if the serialization fails 076 */ 077 public static <T extends Serializable> T clone(final T object) { 078 if (object == null) { 079 return null; 080 } 081 final byte[] objectData = serialize(object); 082 final ByteArrayInputStream bais = new ByteArrayInputStream(objectData); 083 084 try (ClassLoaderAwareObjectInputStream in = new ClassLoaderAwareObjectInputStream(bais, 085 object.getClass().getClassLoader())) { 086 /* 087 * when we serialize and deserialize an object, 088 * it is reasonable to assume the deserialized object 089 * is of the same type as the original serialized object 090 */ 091 @SuppressWarnings("unchecked") // see above 092 final T readObject = (T) in.readObject(); 093 return readObject; 094 095 } catch (final ClassNotFoundException ex) { 096 throw new SerializationException("ClassNotFoundException while reading cloned object data", ex); 097 } catch (final IOException ex) { 098 throw new SerializationException("IOException while reading or closing cloned object data", ex); 099 } 100 } 101 102 /** 103 * Performs a serialization roundtrip. Serializes and deserializes the given object, great for testing objects that 104 * implement {@link Serializable}. 105 * 106 * @param <T> 107 * the type of the object involved 108 * @param msg 109 * the object to roundtrip 110 * @return the serialized and deserialized object 111 * @since 3.3 112 */ 113 @SuppressWarnings("unchecked") // OK, because we serialized a type `T` 114 public static <T extends Serializable> T roundtrip(final T msg) { 115 return (T) deserialize(serialize(msg)); 116 } 117 118 // Serialize 119 //----------------------------------------------------------------------- 120 /** 121 * <p>Serializes an {@code Object} to the specified stream.</p> 122 * 123 * <p>The stream will be closed once the object is written. 124 * This avoids the need for a finally clause, and maybe also exception 125 * handling, in the application code.</p> 126 * 127 * <p>The stream passed in is not buffered internally within this method. 128 * This is the responsibility of your application if desired.</p> 129 * 130 * @param obj the object to serialize to bytes, may be null 131 * @param outputStream the stream to write to, must not be null 132 * @throws IllegalArgumentException if {@code outputStream} is {@code null} 133 * @throws SerializationException (runtime) if the serialization fails 134 */ 135 public static void serialize(final Serializable obj, final OutputStream outputStream) { 136 Validate.notNull(outputStream, "The OutputStream must not be null"); 137 try (ObjectOutputStream out = new ObjectOutputStream(outputStream)) { 138 out.writeObject(obj); 139 } catch (final IOException ex) { 140 throw new SerializationException(ex); 141 } 142 } 143 144 /** 145 * <p>Serializes an {@code Object} to a byte array for 146 * storage/serialization.</p> 147 * 148 * @param obj the object to serialize to bytes 149 * @return a byte[] with the converted Serializable 150 * @throws SerializationException (runtime) if the serialization fails 151 */ 152 public static byte[] serialize(final Serializable obj) { 153 final ByteArrayOutputStream baos = new ByteArrayOutputStream(512); 154 serialize(obj, baos); 155 return baos.toByteArray(); 156 } 157 158 // Deserialize 159 //----------------------------------------------------------------------- 160 /** 161 * <p> 162 * Deserializes an {@code Object} from the specified stream. 163 * </p> 164 * 165 * <p> 166 * The stream will be closed once the object is written. This avoids the need for a finally clause, and maybe also 167 * exception handling, in the application code. 168 * </p> 169 * 170 * <p> 171 * The stream passed in is not buffered internally within this method. This is the responsibility of your 172 * application if desired. 173 * </p> 174 * 175 * <p> 176 * If the call site incorrectly types the return value, a {@link ClassCastException} is thrown from the call site. 177 * Without Generics in this declaration, the call site must type cast and can cause the same ClassCastException. 178 * Note that in both cases, the ClassCastException is in the call site, not in this method. 179 * </p> 180 * 181 * @param <T> the object type to be deserialized 182 * @param inputStream 183 * the serialized object input stream, must not be null 184 * @return the deserialized object 185 * @throws IllegalArgumentException 186 * if {@code inputStream} is {@code null} 187 * @throws SerializationException 188 * (runtime) if the serialization fails 189 */ 190 public static <T> T deserialize(final InputStream inputStream) { 191 Validate.notNull(inputStream, "The InputStream must not be null"); 192 try (ObjectInputStream in = new ObjectInputStream(inputStream)) { 193 @SuppressWarnings("unchecked") 194 final T obj = (T) in.readObject(); 195 return obj; 196 } catch (final ClassNotFoundException | IOException ex) { 197 throw new SerializationException(ex); 198 } 199 } 200 201 /** 202 * <p> 203 * Deserializes a single {@code Object} from an array of bytes. 204 * </p> 205 * 206 * <p> 207 * If the call site incorrectly types the return value, a {@link ClassCastException} is thrown from the call site. 208 * Without Generics in this declaration, the call site must type cast and can cause the same ClassCastException. 209 * Note that in both cases, the ClassCastException is in the call site, not in this method. 210 * </p> 211 * 212 * @param <T> the object type to be deserialized 213 * @param objectData 214 * the serialized object, must not be null 215 * @return the deserialized object 216 * @throws IllegalArgumentException 217 * if {@code objectData} is {@code null} 218 * @throws SerializationException 219 * (runtime) if the serialization fails 220 */ 221 public static <T> T deserialize(final byte[] objectData) { 222 Validate.notNull(objectData, "The byte[] must not be null"); 223 return deserialize(new ByteArrayInputStream(objectData)); 224 } 225 226 /** 227 * <p>Custom specialization of the standard JDK {@link java.io.ObjectInputStream} 228 * that uses a custom {@code ClassLoader} to resolve a class. 229 * If the specified {@code ClassLoader} is not able to resolve the class, 230 * the context classloader of the current thread will be used. 231 * This way, the standard deserialization work also in web-application 232 * containers and application servers, no matter in which of the 233 * {@code ClassLoader} the particular class that encapsulates 234 * serialization/deserialization lives. </p> 235 * 236 * <p>For more in-depth information about the problem for which this 237 * class here is a workaround, see the JIRA issue LANG-626. </p> 238 */ 239 static class ClassLoaderAwareObjectInputStream extends ObjectInputStream { 240 private static final Map<String, Class<?>> primitiveTypes = 241 new HashMap<>(); 242 243 static { 244 primitiveTypes.put("byte", byte.class); 245 primitiveTypes.put("short", short.class); 246 primitiveTypes.put("int", int.class); 247 primitiveTypes.put("long", long.class); 248 primitiveTypes.put("float", float.class); 249 primitiveTypes.put("double", double.class); 250 primitiveTypes.put("boolean", boolean.class); 251 primitiveTypes.put("char", char.class); 252 primitiveTypes.put("void", void.class); 253 } 254 255 private final ClassLoader classLoader; 256 257 /** 258 * Constructor. 259 * @param in The {@code InputStream}. 260 * @param classLoader classloader to use 261 * @throws IOException if an I/O error occurs while reading stream header. 262 * @see java.io.ObjectInputStream 263 */ 264 ClassLoaderAwareObjectInputStream(final InputStream in, final ClassLoader classLoader) throws IOException { 265 super(in); 266 this.classLoader = classLoader; 267 } 268 269 /** 270 * Overridden version that uses the parameterized {@code ClassLoader} or the {@code ClassLoader} 271 * of the current {@code Thread} to resolve the class. 272 * @param desc An instance of class {@code ObjectStreamClass}. 273 * @return A {@code Class} object corresponding to {@code desc}. 274 * @throws IOException Any of the usual Input/Output exceptions. 275 * @throws ClassNotFoundException If class of a serialized object cannot be found. 276 */ 277 @Override 278 protected Class<?> resolveClass(final ObjectStreamClass desc) throws IOException, ClassNotFoundException { 279 final String name = desc.getName(); 280 try { 281 return Class.forName(name, false, classLoader); 282 } catch (final ClassNotFoundException ex) { 283 try { 284 return Class.forName(name, false, Thread.currentThread().getContextClassLoader()); 285 } catch (final ClassNotFoundException cnfe) { 286 final Class<?> cls = primitiveTypes.get(name); 287 if (cls != null) { 288 return cls; 289 } 290 throw cnfe; 291 } 292 } 293 } 294 295 } 296 297}