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| 1 | /* | ||
| 2 | * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved. | ||
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | ||
| 4 | * | ||
| 5 | * This code is free software; you can redistribute it and/or modify it | ||
| 6 | * under the terms of the GNU General Public License version 2 only, as | ||
| 7 | * published by the Free Software Foundation. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | package java.io; | ||
| 27 | |||
| 28 | import java.lang.reflect.Field; | ||
| 29 | |||
| 30 | /** | ||
| 31 | * A description of a Serializable field from a Serializable class. An array | ||
| 32 | * of ObjectStreamFields is used to declare the Serializable fields of a class. | ||
| 33 | * | ||
| 34 | * @author Mike Warres | ||
| 35 | * @author Roger Riggs | ||
| 36 | * @see ObjectStreamClass | ||
| 37 | * @since 1.2 | ||
| 38 | */ | ||
| 39 | public class ObjectStreamField | ||
| 40 | implements Comparable<Object> | ||
| 41 | { | ||
| 42 | |||
| 43 | /** field name */ | ||
| 44 | private final String name; | ||
| 45 | /** canonical JVM signature of field type */ | ||
| 46 | private final String signature; | ||
| 47 | /** field type (Object.class if unknown non-primitive type) */ | ||
| 48 | private final Class<?> type; | ||
| 49 | /** whether or not to (de)serialize field values as unshared */ | ||
| 50 | private final boolean unshared; | ||
| 51 | /** corresponding reflective field object, if any */ | ||
| 52 | private final Field field; | ||
| 53 | /** offset of field value in enclosing field group */ | ||
| 54 | private int offset = 0; | ||
| 55 | |||
| 56 | /** | ||
| 57 | * Create a Serializable field with the specified type. This field should | ||
| 58 | * be documented with a <code>serialField</code> tag. | ||
| 59 | * | ||
| 60 | * @param name the name of the serializable field | ||
| 61 | * @param type the <code>Class</code> object of the serializable field | ||
| 62 | */ | ||
| 63 | public ObjectStreamField(String name, Class<?> type) { | ||
| 64 | this(name, type, false); | ||
| 65 | } | ||
| 66 | |||
| 67 | /** | ||
| 68 | * Creates an ObjectStreamField representing a serializable field with the | ||
| 69 | * given name and type. If unshared is false, values of the represented | ||
| 70 | * field are serialized and deserialized in the default manner--if the | ||
| 71 | * field is non-primitive, object values are serialized and deserialized as | ||
| 72 | * if they had been written and read by calls to writeObject and | ||
| 73 | * readObject. If unshared is true, values of the represented field are | ||
| 74 | * serialized and deserialized as if they had been written and read by | ||
| 75 | * calls to writeUnshared and readUnshared. | ||
| 76 | * | ||
| 77 | * @param name field name | ||
| 78 | * @param type field type | ||
| 79 | * @param unshared if false, write/read field values in the same manner | ||
| 80 | * as writeObject/readObject; if true, write/read in the same | ||
| 81 | * manner as writeUnshared/readUnshared | ||
| 82 | * @since 1.4 | ||
| 83 | */ | ||
| 84 | public ObjectStreamField(String name, Class<?> type, boolean unshared) { | ||
| 85 | if (name == null) { | ||
| 86 | throw new NullPointerException(); | ||
| 87 | } | ||
| 88 | this.name = name; | ||
| 89 | this.type = type; | ||
| 90 | this.unshared = unshared; | ||
| 91 | signature = getClassSignature(type).intern(); | ||
| 92 | field = null; | ||
| 93 | } | ||
| 94 | |||
| 95 | /** | ||
| 96 | * Creates an ObjectStreamField representing a field with the given name, | ||
| 97 | * signature and unshared setting. | ||
| 98 | */ | ||
| 99 | ObjectStreamField(String name, String signature, boolean unshared) { | ||
| 100 | if (name == null) { | ||
| 101 | throw new NullPointerException(); | ||
| 102 | } | ||
| 103 | this.name = name; | ||
| 104 | this.signature = signature.intern(); | ||
| 105 | this.unshared = unshared; | ||
| 106 | field = null; | ||
| 107 | |||
| 108 | switch (signature.charAt(0)) { | ||
| 109 | case 'Z': type = Boolean.TYPE; break; | ||
| 110 | case 'B': type = Byte.TYPE; break; | ||
| 111 | case 'C': type = Character.TYPE; break; | ||
| 112 | case 'S': type = Short.TYPE; break; | ||
| 113 | case 'I': type = Integer.TYPE; break; | ||
| 114 | case 'J': type = Long.TYPE; break; | ||
| 115 | case 'F': type = Float.TYPE; break; | ||
| 116 | case 'D': type = Double.TYPE; break; | ||
| 117 | case 'L': | ||
| 118 | case '[': type = Object.class; break; | ||
| 119 | default: throw new IllegalArgumentException("illegal signature"); | ||
| 120 | } | ||
| 121 | } | ||
| 122 | |||
| 123 | /** | ||
| 124 | * Creates an ObjectStreamField representing the given field with the | ||
| 125 | * specified unshared setting. For compatibility with the behavior of | ||
| 126 | * earlier serialization implementations, a "showType" parameter is | ||
| 127 | * necessary to govern whether or not a getType() call on this | ||
| 128 | * ObjectStreamField (if non-primitive) will return Object.class (as | ||
| 129 | * opposed to a more specific reference type). | ||
| 130 | */ | ||
| 131 | ObjectStreamField(Field field, boolean unshared, boolean showType) { | ||
| 132 | this.field = field; | ||
| 133 | this.unshared = unshared; | ||
| 134 | name = field.getName(); | ||
| 135 | Class<?> ftype = field.getType(); | ||
| 136 | type = (showType || ftype.isPrimitive()) ? ftype : Object.class; | ||
| 137 | signature = getClassSignature(ftype).intern(); | ||
| 138 | } | ||
| 139 | |||
| 140 | /** | ||
| 141 | * Get the name of this field. | ||
| 142 | * | ||
| 143 | * @return a <code>String</code> representing the name of the serializable | ||
| 144 | * field | ||
| 145 | */ | ||
| 146 | public String getName() { | ||
| 147 | return name; | ||
| 148 | } | ||
| 149 | |||
| 150 | /** | ||
| 151 | * Get the type of the field. If the type is non-primitive and this | ||
| 152 | * <code>ObjectStreamField</code> was obtained from a deserialized {@link | ||
| 153 | * ObjectStreamClass} instance, then <code>Object.class</code> is returned. | ||
| 154 | * Otherwise, the <code>Class</code> object for the type of the field is | ||
| 155 | * returned. | ||
| 156 | * | ||
| 157 | * @return a <code>Class</code> object representing the type of the | ||
| 158 | * serializable field | ||
| 159 | */ | ||
| 160 | public Class<?> getType() { | ||
| 161 | return type; | ||
| 162 | } | ||
| 163 | |||
| 164 | /** | ||
| 165 | * Returns character encoding of field type. The encoding is as follows: | ||
| 166 | * <blockquote><pre> | ||
| 167 | * B byte | ||
| 168 | * C char | ||
| 169 | * D double | ||
| 170 | * F float | ||
| 171 | * I int | ||
| 172 | * J long | ||
| 173 | * L class or interface | ||
| 174 | * S short | ||
| 175 | * Z boolean | ||
| 176 | * [ array | ||
| 177 | * </pre></blockquote> | ||
| 178 | * | ||
| 179 | * @return the typecode of the serializable field | ||
| 180 | */ | ||
| 181 | // REMIND: deprecate? | ||
| 182 | public char getTypeCode() { | ||
| 183 | return signature.charAt(0); | ||
| 184 | } | ||
| 185 | |||
| 186 | /** | ||
| 187 | * Return the JVM type signature. | ||
| 188 | * | ||
| 189 | * @return null if this field has a primitive type. | ||
| 190 | */ | ||
| 191 | // REMIND: deprecate? | ||
| 192 | public String getTypeString() { | ||
| 193 | return isPrimitive() ? null : signature; | ||
| 194 | } | ||
| 195 | |||
| 196 | /** | ||
| 197 | * Offset of field within instance data. | ||
| 198 | * | ||
| 199 | * @return the offset of this field | ||
| 200 | * @see #setOffset | ||
| 201 | */ | ||
| 202 | // REMIND: deprecate? | ||
| 203 | public int getOffset() { | ||
| 204 | return offset; | ||
| 205 | } | ||
| 206 | |||
| 207 | /** | ||
| 208 | * Offset within instance data. | ||
| 209 | * | ||
| 210 | * @param offset the offset of the field | ||
| 211 | * @see #getOffset | ||
| 212 | */ | ||
| 213 | // REMIND: deprecate? | ||
| 214 | protected void setOffset(int offset) { | ||
| 215 | this.offset = offset; | ||
| 216 | } | ||
| 217 | |||
| 218 | /** | ||
| 219 | * Return true if this field has a primitive type. | ||
| 220 | * | ||
| 221 | * @return true if and only if this field corresponds to a primitive type | ||
| 222 | */ | ||
| 223 | // REMIND: deprecate? | ||
| 224 | public boolean isPrimitive() { | ||
| 225 | char tcode = signature.charAt(0); | ||
| 226 | return ((tcode != 'L') && (tcode != '[')); | ||
| 227 | } | ||
| 228 | |||
| 229 | /** | ||
| 230 | * Returns boolean value indicating whether or not the serializable field | ||
| 231 | * represented by this ObjectStreamField instance is unshared. | ||
| 232 | * | ||
| 233 | * @since 1.4 | ||
| 234 | */ | ||
| 235 | public boolean isUnshared() { | ||
| 236 | return unshared; | ||
| 237 | } | ||
| 238 | |||
| 239 | /** | ||
| 240 | * Compare this field with another <code>ObjectStreamField</code>. Return | ||
| 241 | * -1 if this is smaller, 0 if equal, 1 if greater. Types that are | ||
| 242 | * primitives are "smaller" than object types. If equal, the field names | ||
| 243 | * are compared. | ||
| 244 | */ | ||
| 245 | // REMIND: deprecate? | ||
| 246 | public int compareTo(Object obj) { | ||
| 247 | ObjectStreamField other = (ObjectStreamField) obj; | ||
| 248 | boolean isPrim = isPrimitive(); | ||
| 249 | if (isPrim != other.isPrimitive()) { | ||
| 250 | return isPrim ? -1 : 1; | ||
| 251 | } | ||
| 252 | return name.compareTo(other.name); | ||
| 253 | } | ||
| 254 | |||
| 255 | /** | ||
| 256 | * Return a string that describes this field. | ||
| 257 | */ | ||
| 258 | public String toString() { | ||
| 259 | return signature + ' ' + name; | ||
| 260 | } | ||
| 261 | |||
| 262 | /** | ||
| 263 | * Returns field represented by this ObjectStreamField, or null if | ||
| 264 | * ObjectStreamField is not associated with an actual field. | ||
| 265 | */ | ||
| 266 | Field getField() { | ||
| 267 | return field; | ||
| 268 | } | ||
| 269 | |||
| 270 | /** | ||
| 271 | * Returns JVM type signature of field (similar to getTypeString, except | ||
| 272 | * that signature strings are returned for primitive fields as well). | ||
| 273 | */ | ||
| 274 | String getSignature() { | ||
| 275 | return signature; | ||
| 276 | } | ||
| 277 | |||
| 278 | /** | ||
| 279 | * Returns JVM type signature for given class. | ||
| 280 | */ | ||
| 281 | private static String getClassSignature(Class<?> cl) { | ||
| 282 | StringBuilder sbuf = new StringBuilder(); | ||
| 283 | while (cl.isArray()) { | ||
| 284 | sbuf.append('['); | ||
| 285 | cl = cl.getComponentType(); | ||
| 286 | } | ||
| 287 | if (cl.isPrimitive()) { | ||
| 288 | if (cl == Integer.TYPE) { | ||
| 289 | sbuf.append('I'); | ||
| 290 | } else if (cl == Byte.TYPE) { | ||
| 291 | sbuf.append('B'); | ||
| 292 | } else if (cl == Long.TYPE) { | ||
| 293 | sbuf.append('J'); | ||
| 294 | } else if (cl == Float.TYPE) { | ||
| 295 | sbuf.append('F'); | ||
| 296 | } else if (cl == Double.TYPE) { | ||
| 297 | sbuf.append('D'); | ||
| 298 | } else if (cl == Short.TYPE) { | ||
| 299 | sbuf.append('S'); | ||
| 300 | } else if (cl == Character.TYPE) { | ||
| 301 | sbuf.append('C'); | ||
| 302 | } else if (cl == Boolean.TYPE) { | ||
| 303 | sbuf.append('Z'); | ||
| 304 | } else if (cl == Void.TYPE) { | ||
| 305 | sbuf.append('V'); | ||
| 306 | } else { | ||
| 307 | throw new InternalError(); | ||
| 308 | } | ||
| 309 | } else { | ||
| 310 | sbuf.append('L' + cl.getName().replace('.', '/') + ';'); | ||
| 311 | } | ||
| 312 | return sbuf.toString(); | ||
| 313 | } | ||
| 314 | } | ||