|
1
15 package org.josql.expressions;
16
17 import java.util.Map  ;
18 import java.util.TreeMap ;
19 import java.util.LinkedHashMap ;
20 import java.util.List ;
21 import java.util.Iterator ;
22
23 import java.lang.reflect.Constructor ;
24
25 import org.josql.internal.Setter;
26 import org.josql.internal.Utilities;
27
28 import org.josql.Query;
29 import org.josql.QueryParseException;
30 import org.josql.QueryExecutionException;
31
32 public class NewObjectExpression extends ValueExpression
33 {
34
35 private String cn = null;
36 private Class clazz = null;
37 private List constructorArgs = null;
38 private Map intoExps = null;
39 private Constructor constructor = null;
40 private Object [] conParms = null;
41 private int argsSize = -1;
42
43 public void addIntoExpression (Expression exp,
44 String setter)
45 {
46
47 if (this.intoExps == null)
48 {
49
50 this.intoExps = new LinkedHashMap ();
51
52 }
53
54 this.intoExps.put (exp,
55 setter);
56
57 }
58
59 public void setConstructorArgs (List exps)
60 {
61
62 this.constructorArgs = exps;
63
64 this.argsSize = exps.size () - 1;
65
66 }
67
68 public void setClassName (String c)
69 {
70
71 this.cn = c;
72
73 }
74
75 public boolean hasFixedResult (Query q)
76 {
77
78 return false;
79
80 }
81
82 public Class getExpectedReturnType (Query q)
83 throws QueryParseException
84 {
85
86 return this.clazz;
87
88 }
89
90 public void init (Query q)
91 throws QueryParseException
92 {
93
94 try
96 {
97
98 this.clazz = q.getClassLoader ().loadClass (this.cn);
100
101 } catch (Exception e) {
102
103 throw new QueryParseException ("Unable to load class: " +
104 this.cn,
105 e);
106
107 }
108
109 Class [] conTypes = null;
110
111 if (this.constructorArgs != null)
113 {
114
115 conTypes = new Class [this.constructorArgs.size ()];
116
117 this.conParms = new Object [this.constructorArgs.size ()];
118
119 for (int i = 0; i < this.constructorArgs.size (); i++)
120 {
121
122 Expression exp = (Expression) this.constructorArgs.get (i);
123
124 exp.init (q);
125
126 conTypes[i] = exp.getExpectedReturnType (q);
127
128 }
129
130 }
131
132 TreeMap tm = new TreeMap ();
133
134 Constructor [] cons = this.clazz.getConstructors ();
135
136 for (int i = 0; i < cons.length; i++)
137 {
138
139 int score = Utilities.matchMethodArgs (cons[i].getParameterTypes (),
140 conTypes);
141
142 if (score > 0)
143 {
144
145 tm.put (new Integer (score),
146 cons[i]);
147
148 }
149
150 }
151
152 if (tm.size () > 0)
153 {
154
155 this.constructor = (Constructor ) tm.get (tm.lastKey ());
156
157 }
158
159 if (this.constructor == null)
161 {
162
163 throw new QueryParseException ("Unable to find constructor: " +
164 Utilities.formatSignature (this.clazz.getName (),
165 conTypes));
166
167 }
168
169 if (this.intoExps != null)
171 {
172
173 Iterator iter = this.intoExps.keySet ().iterator ();
174
175 Class [] pts = new Class [1];
176
177 while (iter.hasNext ())
178 {
179
180 Expression exp = (Expression) iter.next ();
181
182 String setName = (String ) this.intoExps.get (exp);
183
184 exp.init (q);
185
186 pts[0] = exp.getExpectedReturnType (q);
187
188 Setter set = null;
190
191 try
192 {
193
194 set = new Setter (setName,
195 this.clazz,
196 pts);
197
198 } catch (Exception e) {
199
200 throw new QueryParseException ("Unable to create setter for: " +
201 setName,
202 e);
203
204 }
205
206 this.intoExps.put (exp,
207 set);
208
209 }
210
211 }
212
213 }
214
215
223 public boolean isTrue (Object o,
224 Query q)
225 {
226
227 return true;
228
229 }
230
231 public Object evaluate (Object o,
232 Query q)
233 throws QueryExecutionException
234 {
235
236 return this.getValue (o,
237 q);
238
239 }
240
241 public Object getValue (Object o,
242 Query q)
243 throws QueryExecutionException
244 {
245
246 if (this.constructorArgs != null)
248 {
249
250 for (int i = this.argsSize; i > -1; i--)
251 {
252
253 Expression exp = (Expression) this.constructorArgs.get (i);
254
255 try
256 {
257
258 this.conParms[i] = exp.getValue (o,
259 q);
260
261 } catch (Exception e) {
262
263 throw new QueryExecutionException ("Unable to evaluate constructor argument expression: " +
264 exp,
265 e);
266
267 }
268
269 }
270
271 }
272
273 Object obj = null;
275
276 try
277 {
278
279 obj = this.constructor.newInstance (Utilities.convertArgs (this.conParms,
280 this.constructor.getParameterTypes ()));
281
282 } catch (Exception e) {
283
284 throw new QueryExecutionException ("Unable to create new instance of: " +
285 this.clazz.getName () +
286 " using constructor: " +
287 this.constructor +
288 ", passing parameters: " +
289 this.conParms,
290 e);
291
292 }
293
294 if (this.intoExps != null)
296 {
297
298 Iterator iter = this.intoExps.keySet ().iterator ();
299
300 while (iter.hasNext ())
301 {
302
303 Expression exp = (Expression) iter.next ();
304
305 Setter set = (Setter) this.intoExps.get (exp);
306
307 Object so = null;
308
309 try
311 {
312
313 so = exp.getValue (o,
314 q);
315
316 } catch (Exception e) {
317
318 throw new QueryExecutionException ("Unable to evaluate expression: " +
319 exp +
320 " for setter: " +
321 set +
322 " on class: " +
323 this.clazz.getName (),
324 e);
325
326 }
327
328 try
329 {
330
331 set.setValue (obj,
332 so);
333
334 } catch (Exception e) {
335
336 String cn = null + "";
337
338 if (so != null)
339 {
340
341 cn = so.getClass ().getName ();
342
343 }
344
345 throw new QueryExecutionException ("Unable to set value of type: " +
346 cn +
347 " in object of type: " +
348 this.clazz.getName () +
349 " using setter: " +
350 set +
351 " (value is result of expression: " +
352 exp +
353 ")",
354 e);
355
356 }
357
358 }
359
360 }
361
362 return obj;
363
364 }
365
366 public String toString ()
367 {
368
369 StringBuffer b = new StringBuffer ("new ");
370 b.append (this.clazz.getName ());
371 b.append (" (");
372
373 if (this.constructorArgs != null)
374 {
375
376 for (int i = 0; i < this.constructorArgs.size (); i++)
377 {
378
379 Expression exp = (Expression) this.constructorArgs.get (i);
380
381 b.append (exp);
382
383 if (i < this.constructorArgs.size () - 1)
384 {
385
386 b.append (", ");
387
388 }
389
390 }
391
392 }
393
394 b.append (")");
395
396 if (this.intoExps != null)
397 {
398
399 b.append (" {");
400
401 Iterator iter = this.intoExps.keySet ().iterator ();
402
403 while (iter.hasNext ())
404 {
405
406 Expression exp = (Expression) iter.next ();
407
408 b.append (exp);
409
410 b.append (" -> ");
411
412 Object obj = this.intoExps.get (exp);
413
414 if (obj instanceof Setter)
415 {
416
417 Setter set = (Setter) obj;
418
419 b.append (set);
420
421 }
422
423 if (obj instanceof String )
424 {
425
426 b.append ((String ) obj);
427
428 }
429
430 if (iter.hasNext ())
431 {
432
433 b.append (", ");
434
435 }
436
437 }
438
439 b.append ("}");
440
441 }
442
443 return b.toString ();
444
445 }
446
447 }
448 |
Popular Tags |
Java API By Example, From Geeks To Geeks.