| 1 | package be.nikiroo.utils.serial; |
| 2 | |
| 3 | import java.io.NotSerializableException; |
| 4 | import java.lang.reflect.Constructor; |
| 5 | import java.lang.reflect.Field; |
| 6 | import java.util.HashMap; |
| 7 | import java.util.Map; |
| 8 | |
| 9 | /** |
| 10 | * Small class to help with serialisation. |
| 11 | * <p> |
| 12 | * Note that we do not support inner classes (but we do support nested classes) |
| 13 | * and all objects require an empty constructor to be deserialised. |
| 14 | * |
| 15 | * @author niki |
| 16 | */ |
| 17 | public class SerialUtils { |
| 18 | private static Map<String, CustomSerializer> customTypes; |
| 19 | |
| 20 | static { |
| 21 | customTypes = new HashMap<String, CustomSerializer>(); |
| 22 | // TODO: add "default" custom serialisers if any (Bitmap?) |
| 23 | } |
| 24 | |
| 25 | /** |
| 26 | * Create an empty object of the given type. |
| 27 | * |
| 28 | * @param type |
| 29 | * the object type (its class name) |
| 30 | * |
| 31 | * @return the new object |
| 32 | * |
| 33 | * @throws ClassNotFoundException |
| 34 | * if the class cannot be found |
| 35 | * @throws NoSuchMethodException |
| 36 | * if the given class is not compatible with this code |
| 37 | */ |
| 38 | public static Object createObject(String type) |
| 39 | throws ClassNotFoundException, NoSuchMethodException { |
| 40 | |
| 41 | try { |
| 42 | Class<?> clazz = getClass(type); |
| 43 | String className = clazz.getName(); |
| 44 | Object[] args = null; |
| 45 | Constructor<?> ctor = null; |
| 46 | if (className.contains("$")) { |
| 47 | Object javaParent = createObject(className.substring(0, |
| 48 | className.lastIndexOf('$'))); |
| 49 | args = new Object[] { javaParent }; |
| 50 | ctor = clazz.getDeclaredConstructor(new Class[] { javaParent |
| 51 | .getClass() }); |
| 52 | } else { |
| 53 | args = new Object[] {}; |
| 54 | ctor = clazz.getDeclaredConstructor(); |
| 55 | } |
| 56 | |
| 57 | ctor.setAccessible(true); |
| 58 | return ctor.newInstance(args); |
| 59 | } catch (ClassNotFoundException e) { |
| 60 | throw e; |
| 61 | } catch (NoSuchMethodException e) { |
| 62 | throw e; |
| 63 | } catch (Exception e) { |
| 64 | throw new NoSuchMethodException("Cannot instantiate: " + type); |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | /** |
| 69 | * Insert a custom serialiser that will take precedence over the default one |
| 70 | * or the target class. |
| 71 | * |
| 72 | * @param serializer |
| 73 | * the custom serialiser |
| 74 | */ |
| 75 | static public void addCustomSerializer(CustomSerializer serializer) { |
| 76 | customTypes.put(serializer.getType(), serializer); |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * Serialise the given object into this {@link StringBuilder}. |
| 81 | * <p> |
| 82 | * <b>Important: </b>If the operation fails (with a |
| 83 | * {@link NotSerializableException}), the {@link StringBuilder} will be |
| 84 | * corrupted (will contain bad, most probably not importable data). |
| 85 | * |
| 86 | * @param builder |
| 87 | * the output {@link StringBuilder} to serialise to |
| 88 | * @param o |
| 89 | * the object to serialise |
| 90 | * @param map |
| 91 | * the map of already serialised objects (if the given object or |
| 92 | * one of its descendant is already present in it, only an ID |
| 93 | * will be serialised) |
| 94 | * |
| 95 | * @throws NotSerializableException |
| 96 | * if the object cannot be serialised (in this case, the |
| 97 | * {@link StringBuilder} can contain bad, most probably not |
| 98 | * importable data) |
| 99 | */ |
| 100 | static void append(StringBuilder builder, Object o, Map<Integer, Object> map) |
| 101 | throws NotSerializableException { |
| 102 | |
| 103 | Field[] fields = new Field[] {}; |
| 104 | String type = ""; |
| 105 | String id = "NULL"; |
| 106 | |
| 107 | if (o != null) { |
| 108 | int hash = System.identityHashCode(o); |
| 109 | fields = o.getClass().getDeclaredFields(); |
| 110 | type = o.getClass().getCanonicalName(); |
| 111 | if (type == null) { |
| 112 | throw new NotSerializableException( |
| 113 | String.format( |
| 114 | "Cannot find the class for this object: %s (it could be an inner class, which is not supported)", |
| 115 | o)); |
| 116 | } |
| 117 | id = Integer.toString(hash); |
| 118 | if (map.containsKey(hash)) { |
| 119 | fields = new Field[] {}; |
| 120 | } else { |
| 121 | map.put(hash, o); |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | builder.append("{\nREF ").append(type).append("@").append(id); |
| 126 | try { |
| 127 | for (Field field : fields) { |
| 128 | field.setAccessible(true); |
| 129 | |
| 130 | if (field.getName().startsWith("this$")) { |
| 131 | // Do not keep this links of nested classes |
| 132 | continue; |
| 133 | } |
| 134 | |
| 135 | builder.append("\n"); |
| 136 | builder.append(field.getName()); |
| 137 | builder.append(":"); |
| 138 | Object value; |
| 139 | |
| 140 | value = field.get(o); |
| 141 | |
| 142 | if (!encode(builder, value)) { |
| 143 | builder.append("\n"); |
| 144 | append(builder, value, map); |
| 145 | } |
| 146 | } |
| 147 | } catch (IllegalArgumentException e) { |
| 148 | e.printStackTrace(); // should not happen (see setAccessible) |
| 149 | } catch (IllegalAccessException e) { |
| 150 | e.printStackTrace(); // should not happen (see setAccessible) |
| 151 | } |
| 152 | builder.append("\n}"); |
| 153 | } |
| 154 | |
| 155 | // return true if encoded (supported) |
| 156 | static boolean encode(StringBuilder builder, Object value) { |
| 157 | if (value == null) { |
| 158 | builder.append("NULL"); |
| 159 | } else if (customTypes.containsKey(value.getClass().getCanonicalName())) { |
| 160 | customTypes.get(value.getClass().getCanonicalName())// |
| 161 | .encode(builder, value); |
| 162 | } else if (value instanceof String) { |
| 163 | encodeString(builder, (String) value); |
| 164 | } else if (value instanceof Boolean) { |
| 165 | builder.append(value); |
| 166 | } else if (value instanceof Byte) { |
| 167 | builder.append(value).append('b'); |
| 168 | } else if (value instanceof Character) { |
| 169 | encodeString(builder, (String) value); |
| 170 | builder.append('c'); |
| 171 | } else if (value instanceof Short) { |
| 172 | builder.append(value).append('s'); |
| 173 | } else if (value instanceof Integer) { |
| 174 | builder.append(value); |
| 175 | } else if (value instanceof Long) { |
| 176 | builder.append(value).append('L'); |
| 177 | } else if (value instanceof Float) { |
| 178 | builder.append(value).append('F'); |
| 179 | } else if (value instanceof Double) { |
| 180 | builder.append(value).append('d'); |
| 181 | } else { |
| 182 | return false; |
| 183 | } |
| 184 | |
| 185 | return true; |
| 186 | } |
| 187 | |
| 188 | static Object decode(String encodedValue) { |
| 189 | String cut = ""; |
| 190 | if (encodedValue.length() > 1) { |
| 191 | cut = encodedValue.substring(0, encodedValue.length() - 1); |
| 192 | } |
| 193 | |
| 194 | if (CustomSerializer.isCustom(encodedValue)) { |
| 195 | // custom:TYPE_NAME:"content is String-encoded" |
| 196 | String type = CustomSerializer.typeOf(encodedValue); |
| 197 | if (customTypes.containsKey(type)) { |
| 198 | return customTypes.get(type).decode(encodedValue); |
| 199 | } else { |
| 200 | throw new java.util.UnknownFormatConversionException( |
| 201 | "Unknown custom type: " + type); |
| 202 | } |
| 203 | } else if (encodedValue.equals("NULL") || encodedValue.equals("null")) { |
| 204 | return null; |
| 205 | } else if (encodedValue.endsWith("\"")) { |
| 206 | return decodeString(encodedValue); |
| 207 | } else if (encodedValue.equals("true")) { |
| 208 | return true; |
| 209 | } else if (encodedValue.equals("false")) { |
| 210 | return false; |
| 211 | } else if (encodedValue.endsWith("b")) { |
| 212 | return Byte.parseByte(cut); |
| 213 | } else if (encodedValue.endsWith("c")) { |
| 214 | return decodeString(cut).charAt(0); |
| 215 | } else if (encodedValue.endsWith("s")) { |
| 216 | return Short.parseShort(cut); |
| 217 | } else if (encodedValue.endsWith("L")) { |
| 218 | return Long.parseLong(cut); |
| 219 | } else if (encodedValue.endsWith("F")) { |
| 220 | return Float.parseFloat(cut); |
| 221 | } else if (encodedValue.endsWith("d")) { |
| 222 | return Double.parseDouble(cut); |
| 223 | } else { |
| 224 | return Integer.parseInt(encodedValue); |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Return the corresponding class or throw an {@link Exception} if it |
| 230 | * cannot. |
| 231 | * |
| 232 | * @param type |
| 233 | * the class name to look for |
| 234 | * |
| 235 | * @return the class (will never be NULL) |
| 236 | * |
| 237 | * @throws ClassNotFoundException |
| 238 | * if the class cannot be found |
| 239 | * @throws NoSuchMethodException |
| 240 | * if the class cannot be created (usually because it or its |
| 241 | * enclosing class doesn't have an empty constructor) |
| 242 | */ |
| 243 | static private Class<?> getClass(String type) |
| 244 | throws ClassNotFoundException, NoSuchMethodException { |
| 245 | Class<?> clazz = null; |
| 246 | try { |
| 247 | clazz = Class.forName(type); |
| 248 | } catch (ClassNotFoundException e) { |
| 249 | int pos = type.length(); |
| 250 | pos = type.lastIndexOf(".", pos); |
| 251 | if (pos >= 0) { |
| 252 | String parentType = type.substring(0, pos); |
| 253 | String nestedType = type.substring(pos + 1); |
| 254 | Class<?> javaParent = null; |
| 255 | try { |
| 256 | javaParent = getClass(parentType); |
| 257 | parentType = javaParent.getName(); |
| 258 | clazz = Class.forName(parentType + "$" + nestedType); |
| 259 | } catch (Exception ee) { |
| 260 | } |
| 261 | |
| 262 | if (javaParent == null) { |
| 263 | throw new NoSuchMethodException( |
| 264 | "Class not found: " |
| 265 | + type |
| 266 | + " (the enclosing class cannot be created: maybe it doesn't have an empty constructor?)"); |
| 267 | } |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | if (clazz == null) { |
| 272 | throw new ClassNotFoundException("Class not found: " + type); |
| 273 | } |
| 274 | |
| 275 | return clazz; |
| 276 | } |
| 277 | |
| 278 | // aa bb -> "aa\tbb" |
| 279 | private static void encodeString(StringBuilder builder, String raw) { |
| 280 | builder.append('\"'); |
| 281 | for (char car : raw.toCharArray()) { |
| 282 | switch (car) { |
| 283 | case '\\': |
| 284 | builder.append("\\\\"); |
| 285 | break; |
| 286 | case '\r': |
| 287 | builder.append("\\r"); |
| 288 | break; |
| 289 | case '\n': |
| 290 | builder.append("\\n"); |
| 291 | break; |
| 292 | case '"': |
| 293 | builder.append("\\\""); |
| 294 | break; |
| 295 | default: |
| 296 | builder.append(car); |
| 297 | break; |
| 298 | } |
| 299 | } |
| 300 | builder.append('\"'); |
| 301 | } |
| 302 | |
| 303 | // "aa\tbb" -> aa bb |
| 304 | private static String decodeString(String escaped) { |
| 305 | StringBuilder builder = new StringBuilder(); |
| 306 | |
| 307 | boolean escaping = false; |
| 308 | for (char car : escaped.toCharArray()) { |
| 309 | if (!escaping) { |
| 310 | if (car == '\\') { |
| 311 | escaping = true; |
| 312 | } else { |
| 313 | builder.append(car); |
| 314 | } |
| 315 | } else { |
| 316 | switch (car) { |
| 317 | case '\\': |
| 318 | builder.append('\\'); |
| 319 | break; |
| 320 | case 'r': |
| 321 | builder.append('\r'); |
| 322 | break; |
| 323 | case 'n': |
| 324 | builder.append('\n'); |
| 325 | break; |
| 326 | case '"': |
| 327 | builder.append('"'); |
| 328 | break; |
| 329 | } |
| 330 | escaping = false; |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | return builder.substring(1, builder.length() - 1).toString(); |
| 335 | } |
| 336 | } |