1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package java.io; 19 20 /** 21 * An EmulatedFieldsForLoading is an object that represents a set of emulated 22 * fields for an object being loaded. It is a concrete implementation for 23 * ObjectInputStream.GetField 24 * 25 * @see ObjectInputStream.GetField 26 * @see EmulatedFieldsForDumping 27 */ 28 class EmulatedFieldsForLoading extends ObjectInputStream.GetField { 29 30 // The class descriptor with the declared fields the receiver emulates 31 private ObjectStreamClass streamClass; 32 33 // The actual representation, with a more powerful API (set&get) 34 private EmulatedFields emulatedFields; 35 36 /** 37 * Constructs a new instance of EmulatedFieldsForDumping. 38 * 39 * @param streamClass 40 * an ObjectStreamClass, defining the class for which to emulate 41 * fields. 42 */ 43 EmulatedFieldsForLoading(ObjectStreamClass streamClass) { 44 this.streamClass = streamClass; 45 emulatedFields = new EmulatedFields(streamClass.getLoadFields(), streamClass.fields()); 46 } 47 48 /** 49 * Return a boolean indicating if the field named <code>name</code> has 50 * been assigned a value explicitly (false) or if it still holds a default 51 * value for the type (true) because it hasn't been assigned to yet. 52 * 53 * @param name 54 * A String, the name of the field to test 55 * @return <code>true</code> if the field holds it default value, 56 * <code>false</code> otherwise. 57 * 58 * @throws IOException 59 * If an IO error occurs 60 * @throws IllegalArgumentException 61 * If the corresponding field can not be found. 62 */ 63 @Override 64 public boolean defaulted(String name) throws IOException, 65 IllegalArgumentException { 66 return emulatedFields.defaulted(name); 67 } 68 69 /** 70 * Return the actual EmulatedFields instance used by the receiver. We have 71 * the actual work in a separate class so that the code can be shared. The 72 * receiver has to be of a subclass of GetField. 73 * 74 * @return array of ObjectSlot the receiver represents. 75 */ 76 EmulatedFields emulatedFields() { 77 return emulatedFields; 78 } 79 80 /** 81 * Find and return the byte value of a given field named <code>name</code> 82 * in the receiver. If the field has not been assigned any value yet, the 83 * default value <code>defaultValue</code> is returned instead. 84 * 85 * @param name 86 * A String, the name of the field to find 87 * @param defaultValue 88 * Return value in case the field has not been assigned to yet. 89 * @return the value of the given field if it has been assigned, or the 90 * default value otherwise 91 * 92 * @throws IOException 93 * If an IO error occurs 94 * @throws IllegalArgumentException 95 * If the corresponding field can not be found. 96 */ 97 @Override 98 public byte get(String name, byte defaultValue) throws IOException, 99 IllegalArgumentException { 100 return emulatedFields.get(name, defaultValue); 101 } 102 103 /** 104 * Find and return the char value of a given field named <code>name</code> 105 * in the receiver. If the field has not been assigned any value yet, the 106 * default value <code>defaultValue</code> is returned instead. 107 * 108 * @param name 109 * A String, the name of the field to find 110 * @param defaultValue 111 * Return value in case the field has not been assigned to yet. 112 * @return the value of the given field if it has been assigned, or the 113 * default value otherwise 114 * 115 * @throws IOException 116 * If an IO error occurs 117 * @throws IllegalArgumentException 118 * If the corresponding field can not be found. 119 */ 120 @Override 121 public char get(String name, char defaultValue) throws IOException, 122 IllegalArgumentException { 123 return emulatedFields.get(name, defaultValue); 124 } 125 126 /** 127 * Find and return the double value of a given field named <code>name</code> 128 * in the receiver. If the field has not been assigned any value yet, the 129 * default value <code>defaultValue</code> is returned instead. 130 * 131 * @param name 132 * A String, the name of the field to find 133 * @param defaultValue 134 * Return value in case the field has not been assigned to yet. 135 * @return the value of the given field if it has been assigned, or the 136 * default value otherwise 137 * 138 * @throws IOException 139 * If an IO error occurs 140 * @throws IllegalArgumentException 141 * If the corresponding field can not be found. 142 */ 143 @Override 144 public double get(String name, double defaultValue) throws IOException, 145 IllegalArgumentException { 146 return emulatedFields.get(name, defaultValue); 147 } 148 149 /** 150 * Find and return the float value of a given field named <code>name</code> 151 * in the receiver. If the field has not been assigned any value yet, the 152 * default value <code>defaultValue</code> is returned instead. 153 * 154 * @param name 155 * A String, the name of the field to find 156 * @param defaultValue 157 * Return value in case the field has not been assigned to yet. 158 * @return the value of the given field if it has been assigned, or the 159 * default value otherwise 160 * 161 * @throws IOException 162 * If an IO error occurs 163 * @throws IllegalArgumentException 164 * If the corresponding field can not be found. 165 */ 166 @Override 167 public float get(String name, float defaultValue) throws IOException, 168 IllegalArgumentException { 169 return emulatedFields.get(name, defaultValue); 170 } 171 172 /** 173 * Find and return the int value of a given field named <code>name</code> 174 * in the receiver. If the field has not been assigned any value yet, the 175 * default value <code>defaultValue</code> is returned instead. 176 * 177 * @param name 178 * A String, the name of the field to find 179 * @param defaultValue 180 * Return value in case the field has not been assigned to yet. 181 * @return the value of the given field if it has been assigned, or the 182 * default value otherwise 183 * 184 * @throws IOException 185 * If an IO error occurs 186 * @throws IllegalArgumentException 187 * If the corresponding field can not be found. 188 */ 189 @Override 190 public int get(String name, int defaultValue) throws IOException, 191 IllegalArgumentException { 192 return emulatedFields.get(name, defaultValue); 193 } 194 195 /** 196 * Find and return the long value of a given field named <code>name</code> 197 * in the receiver. If the field has not been assigned any value yet, the 198 * default value <code>defaultValue</code> is returned instead. 199 * 200 * @param name 201 * A String, the name of the field to find 202 * @param defaultValue 203 * Return value in case the field has not been assigned to yet. 204 * @return the value of the given field if it has been assigned, or the 205 * default value otherwise 206 * 207 * @throws IOException 208 * If an IO error occurs 209 * @throws IllegalArgumentException 210 * If the corresponding field can not be found. 211 */ 212 @Override 213 public long get(String name, long defaultValue) throws IOException, 214 IllegalArgumentException { 215 return emulatedFields.get(name, defaultValue); 216 } 217 218 /** 219 * Find and return the Object value of a given field named <code>name</code> 220 * in the receiver. If the field has not been assigned any value yet, the 221 * default value <code>defaultValue</code> is returned instead. 222 * 223 * @param name 224 * A String, the name of the field to find 225 * @param defaultValue 226 * Return value in case the field has not been assigned to yet. 227 * @return the value of the given field if it has been assigned, or the 228 * default value otherwise 229 * 230 * @throws IOException 231 * If an IO error occurs 232 * @throws IllegalArgumentException 233 * If the corresponding field can not be found. 234 */ 235 @Override 236 public Object get(String name, Object defaultValue) throws IOException, 237 IllegalArgumentException { 238 return emulatedFields.get(name, defaultValue); 239 } 240 241 /** 242 * Find and return the short value of a given field named <code>name</code> 243 * in the receiver. If the field has not been assigned any value yet, the 244 * default value <code>defaultValue</code> is returned instead. 245 * 246 * @param name 247 * A String, the name of the field to find 248 * @param defaultValue 249 * Return value in case the field has not been assigned to yet. 250 * @return the value of the given field if it has been assigned, or the 251 * default value otherwise 252 * 253 * @throws IOException 254 * If an IO error occurs 255 * @throws IllegalArgumentException 256 * If the corresponding field can not be found. 257 */ 258 @Override 259 public short get(String name, short defaultValue) throws IOException, 260 IllegalArgumentException { 261 return emulatedFields.get(name, defaultValue); 262 } 263 264 /** 265 * Find and return the boolean value of a given field named 266 * <code>name</code> in the receiver. If the field has not been assigned 267 * any value yet, the default value <code>defaultValue</code> is returned 268 * instead. 269 * 270 * @param name 271 * A String, the name of the field to find 272 * @param defaultValue 273 * Return value in case the field has not been assigned to yet. 274 * @return the value of the given field if it has been assigned, or the 275 * default value otherwise 276 * 277 * @throws IOException 278 * If an IO error occurs 279 * @throws IllegalArgumentException 280 * If the corresponding field can not be found. 281 */ 282 @Override 283 public boolean get(String name, boolean defaultValue) throws IOException, 284 IllegalArgumentException { 285 return emulatedFields.get(name, defaultValue); 286 } 287 288 /** 289 * Return the class descriptor for which the emulated fields are defined. 290 * 291 * @return ObjectStreamClass The class descriptor for which the emulated 292 * fields are defined. 293 */ 294 @Override 295 public ObjectStreamClass getObjectStreamClass() { 296 return streamClass; 297 } 298 } 299
