1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Structure mapping between XML and Java</title>
<style type="text/css">
@import url("../style/tigris.css");
@import url("../style/maven.css");
.dtd-comment {
color: #993399;
font-weight: bold;
</style>
<script type="text/javascript">
if (document.layers) {
document.writeln('<link rel="stylesheet" type="text/css" href="../style/ns4_only.css" media="screen" /><link rel="stylesheet" type="text/css" href="../style/maven_ns4_only.css" media="screen" />')
}
</script>
<link rel="stylesheet" type="text/css" href="../style/print.css" media="print" />
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<body class="composite">
<div id="banner">
<table border="0" cellspacing="0" cellpadding="8" width="100%">
<tbody>
<tr>
<td><h1>Structure mapping between XML and Java</h1>
</td>
<td>
<div align="right" id="login"><a href="http://sourceforge.net">
<img src="http://sourceforge.net/sflogo.php?group_id=69358&type=5"
width="210" height="62" border="0" alt="SourceForge.net Logo"></a></div>
</td>
</tr>
</tbody>
</table>
</div>
<div id="breadcrumbs">
<table border="0" cellspacing="0" cellpadding="4" width="100%">
<tbody>
<tr>
<td>
<div align="right">
<a href="../index.html">Home Page</a> |
<a href="http://www.sourceforge.net/projects/jibx/">SourceForge Page</a> |
<a href="../mail-lists.html">Mailing Lists</a> |
<a href="http://wiki.jibx.org">Wiki</a> |
<a href="../bugs.html">Bugs</a> |
<a href="http://sourceforge.net/project/showfiles.php?group_id=69358">Downloads</a>
</div>
</td>
</tr>
</tbody>
</table>
</div>
<table border="0" cellspacing="0" cellpadding="8" width="100%" id="main">
<tbody>
<tr valign="top">
<td id="leftcol" width="20%">
<div id="navcolumn">
<div>
<strong>JiBX Basics</strong>
<div>
<small>
<a href="../index.html">Overview</a>
</small>
<div>
<small>
<a href="../flexibility.html">Flexibility</a>
</small>
</div>
<div>
<small>
<a href="../performance.html">Performance</a>
</small>
</div>
<div>
<small>
<a href="../clean-code.html">Clean code</a>
</small>
</div>
</div>
<div>
<small>
<a href="../status.html">News and Status</a>
</small>
</div>
<div>
<small>
<a href="../comments.html">User Comments</a>
</small>
</div>
<div>
<small>
<a href="../bugs.html">Bugs</a>
</small>
</div>
<div>
<small>
<a href="../start.html">Getting Started</a>
</small>
<div>
<small>
<a href="binding-tutorial.html">Binding Tutorial</a>
</small>
<div>
<small>
<a href="binding-start.html">A basic binding</a>
</small>
</div>
<div>
<small>
<a href="binding-extras.html">Binding extras</a>
</small>
</div>
<div>
<small>
<span class="menu-selection">Structure mapping</span>
</small>
</div>
<div>
<small>
<a href="binding-collects.html">Collections</a>
</small>
</div>
<div>
<small>
<a href="binding-mappings.html">Using mappings</a>
</small>
</div>
<div>
<small>
<a href="binding-advanced.html">Advanced binding</a>
</small>
</div>
<div>
<small>
<a href="binding-extend.html">Method hooks</a>
</small>
</div>
<div>
<small>
<a href="binding-custom.html">Custom code</a>
</small>
</div>
</div>
<div>
<small>
<a href="../bindcomp.html">Binding Compiler</a>
</small>
</div>
<div>
<small>
<a href="../bindonload.html">Binding on Load</a>
</small>
</div>
<div>
<small>
<a href="../runtime.html">Runtime</a>
</small>
</div>
<div>
<small>
<a href="../extras.html">JiBX Extras</a>
</small>
</div>
<div>
<small>
<a href="../building.html">Building JiBX</a>
</small>
</div>
</div>
<div>
<small>
<a href="../schema.html">Schema Compatibility</a>
</small>
</div>
<div>
<small>
<a href="../mail-lists.html">Mailing Lists</a>
</small>
</div>
<div>
<small>
<a href="../faq.html">FAQ</a>
</small>
</div>
<div>
<small>
<a href="../contributing.html">Contributing</a>
</small>
</div>
<div>
<small>
<a href="../jibx-license.html">License</a>
</small>
</div>
</div>
<div>
<strong>Binding Definition</strong>
<div>
<small>
<a href="../details/binding-overview.html">Definition details</a>
</small>
<div>
<small>
<a href="../details/contexts.html">Definition contexts</a>
</small>
</div>
<div>
<small>
<a href="../details/conversions.html">Conversions</a>
</small>
</div>
<div>
<small>
<a href="../details/xml-summary.html">XML summary</a>
</small>
</div>
<div>
<small>
<a href="../details/binding-element.html"><binding> element</a>
</small>
</div>
<div>
<small>
<a href="../details/include-element.html"><include> element</a>
</small>
</div>
<div>
<small>
<a href="../details/format-element.html"><format> element</a>
</small>
</div>
<div>
<small>
<a href="../details/namespace-element.html"><namespace> element</a>
</small>
</div>
<div>
<small>
<a href="../details/mapping-element.html"><mapping> element</a>
</small>
</div>
<div>
<small>
<a href="../details/value-element.html"><value> element</a>
</small>
</div>
<div>
<small>
<a href="../details/structure-element.html"><structure> element</a>
</small>
</div>
<div>
<small>
<a href="../details/collection-element.html"><collection> element</a>
</small>
</div>
<div>
<small>
<a href="../details/binding-attributes.html">Attribute groups</a>
</small>
</div>
</div>
</div>
<div>
<strong>Usage API</strong>
<div>
<small>
<a href=".././api/index.html">Runtime JavaDocs</a>
</small>
</div>
</div>
<div>
<strong>Subprojects</strong>
<div>
<small>
<a href="../jibxtools/index.html">Generator Tools</a>
</small>
</div>
<div>
<small>
<a href="../jibxsoap/index.html">JibxSoap</a>
</small>
</div>
<div>
<small>
<a href="../siteamatic/index.html">SiteAMatic</a>
</small>
</div>
<div>
<small>
<a href="../xsd2jibx/index.html">Xsd2Jibx</a>
</small>
</div>
</div>
</div>
</td>
<td>
<div id="bodycol">
<div class="app">
<div class="h3">
<h3><a name="intro">Structure mapping</a></h3>
<p>JiBX's binding definition file provides great flexibility for
converting between XML documents and Java object structures. Other data
binding frameworks generally limit customization to just the names and
the style (attribute or element) of XML representations. JiBX goes
further by allowing <b><i>structure mapping</i></b> between XML and object
structures.</p>
<p><a href="#figure4">Figure 4</a> shows the same example as
<a href="binding-start.html#figure1">Figure 1</a>. This basic type of binding, where the
structure of the XML is the same as the structure of the Java objects, is typical
of what's supported by most data binding frameworks.</p>
<a name="figure4"><b>Figure 4. Simple binding example</b></a><br>
<img src="images/structure1.gif" width="578" height="296" alt="Simple binding example"/>
<p>What most frameworks will <b><i>not</i></b> allow you to do is to bring
the values within the <b>name</b> element into the the object that corresponds
to the <b>customer</b> element. In other words, you can't map the XML to this
class:</p>
<div id="source"><pre> public class Customer {
public int customerNumber;
public String firstName;
public String lastName;
public String street;
public String city;
public String state;
public Integer zip;
public String phone;
}
</pre></div>
<p>Nor can you map the XML to a pair of classes like these:</p>
<div id="source"><pre> public class Customer {
public int customerNumber;
public String firstName;
public String lastName;
public Address address;
public String phone;
}
public class Address {
public String street1;
public String city;
public String state;
public String zip;
}
</pre></div>
<p>JiBX <b><i>does</i></b> allow you to do this type of mapping. This means
the structure of your objects is not tied to the structure of the XML - you
can restructure your object classes without needing to change the XML format
used for external data transfer. <a href="#figure5">Figure 5</a> shows a binding
definition for the first case above, with the changes shown in blue.</p>
<a name="figure5"><b>Figure 5. Flattened binding</b></a><br>
<img src="images/structure2.gif" width="578" height="296" alt="Flattened binding"/>
<p>The only difference in this binding definition from <a href="#figure4">Figure
4</a> is that I've removed the <b>field</b> attribute from the <b>structure</b>
element. The structure still defines an XML element name, but without the <b>field</b>
attribute the values within that XML element are treated as properties of the
containing object (the <code>Customer</code> class instance).</p>
<p>Adding a new <b>structure</b> element to the binding definition
handles the second structure change case, as shown in <a href="#figure6">Figure
6</a>. I've highlighted the changes from <a href="#figure4">Figure 4</a> in
green.</p>
<a name="figure6"><b>Figure 6. Split binding</b></a><br>
<img src="images/structure3.gif" width="578" height="334" alt="Split binding"/>
<p>Here the added <b>structure</b> element uses a <b>field</b> attribute
but no <b>name</b> attribute. This tells JiBX that the properties from the
<code>Address</code> class instance referenced by the <code>address</code>
field should be included directly as children of the <b>customer</b>
element in the XML document.</p>
<p>As a final example of structure mapping, <a href="#figure7">Figure 7</a>
demonstrates partial mappings, where not all the components of the XML document
or the Java classes are actually included in the binding. On the Java side, all
that's needed is to leave something out of the binding defintion, as shown
highlighted in blue for the <code>Person</code> class. On the XML side, the green
highlighted portions of the diagram show how you can use a
<b>structure</b> element in the binding definition with a <b>name</b> attribute
but no property or child definitions. This tells JiBX to require an element with
that name but ignore any content when unmarshalling. When marshalling, the
element will always be generated as empty. If the <b>structure</b> is optional
rather than required, the corresponding element will be ignored (if present) when
unmarshalling and will be skipped completely when marshalling. See the <a
href="../details/structure-element.html"><structure> element</a> details page for more
information on the different usages of the <b>structure</b> element.</p>
<a name="figure7"><b>Figure 7. Ignored components</b></a><br>
<img src="images/structure4.gif" width="578" height="302" alt="Ignored components"/>
<p>The flexibility provided by structure mapping allows you to decouple your
XML data representations from your actual Java class structure. It lets you interface
existing code to new XML representations, and also lets you preserve an existing
XML representation while refactoring your code to better represent the use of
data within your application. This decoupling of XML structure from code structure
is one of the most powerful features of the JiBX framework.</p>
<div><p align="center"><a href="binding-collects.html"><b>Next: Working with collections and IDs</b></a></p></div>
</div>
</div>
</div>
</td>
</tr>
</tbody>
</table>
<div id="footer">
<table border="0" cellspacing="0" cellpadding="4">
<tbody>
<tr>
<td> © 2003-2005, Dennis M. Sosnoski (<a href="http://www.sosnoski.com">Sosnoski Software Solutions, Inc.</a>).
Licensed to the JiBX Project for free distribution and use. </td>
</tr>
</tbody>
</table>
</div>
<br>
</body>
</html>
|
