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db31c358 NR |
1 | package be.nikiroo.utils.serial; |
2 | ||
3 | import java.io.NotSerializableException; | |
8c8da42a | 4 | import java.lang.reflect.Constructor; |
db31c358 NR |
5 | import java.lang.reflect.Field; |
6 | import java.util.HashMap; | |
7 | import java.util.Map; | |
8 | ||
9 | /** | |
8c8da42a | 10 | * Small class to help with serialisation. |
db31c358 NR |
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 | */ | |
aad14586 | 17 | public class SerialUtils { |
db31c358 NR |
18 | private static Map<String, CustomSerializer> customTypes; |
19 | ||
20 | static { | |
21 | customTypes = new HashMap<String, CustomSerializer>(); | |
8c8da42a | 22 | // TODO: add "default" custom serialisers if any (Bitmap?) |
db31c358 | 23 | } |
8c8da42a | 24 | |
aad14586 NR |
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 | * | |
8c8da42a NR |
33 | * @throws ClassNotFoundException |
34 | * if the class cannot be found | |
35 | * @throws NoSuchMethodException | |
36 | * if the given class is not compatible with this code | |
aad14586 | 37 | */ |
8c8da42a NR |
38 | public static Object createObject(String type) |
39 | throws ClassNotFoundException, NoSuchMethodException { | |
aad14586 NR |
40 | |
41 | try { | |
42 | Class<?> clazz = getClass(type); | |
aad14586 NR |
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); | |
8c8da42a NR |
59 | } catch (ClassNotFoundException e) { |
60 | throw e; | |
aad14586 | 61 | } catch (NoSuchMethodException e) { |
8c8da42a NR |
62 | throw e; |
63 | } catch (Exception e) { | |
64 | throw new NoSuchMethodException("Cannot instantiate: " + type); | |
aad14586 | 65 | } |
aad14586 | 66 | } |
db31c358 | 67 | |
8c8da42a NR |
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 | */ | |
db31c358 NR |
75 | static public void addCustomSerializer(CustomSerializer serializer) { |
76 | customTypes.put(serializer.getType(), serializer); | |
77 | } | |
78 | ||
8c8da42a NR |
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 | */ | |
db31c358 NR |
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 | } | |
8c8da42a NR |
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 { | |
aad14586 NR |
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 | } | |
db31c358 | 261 | |
aad14586 NR |
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 | ||
8c8da42a NR |
271 | if (clazz == null) { |
272 | throw new ClassNotFoundException("Class not found: " + type); | |
273 | } | |
274 | ||
aad14586 NR |
275 | return clazz; |
276 | } | |
8c8da42a | 277 | |
db31c358 NR |
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 | } |