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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575
|
<!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/projects/jibx"><img src="http://sflogo.sourceforge.net/sflogo.php?group_id=69358&type=16" width="150" height="40" border="0" alt="Get JiBX - XML Data Binding for Java at SourceForge.net. Fast, secure and Free Open Source software downloads" /></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="../../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="../../getting-started.html">Getting Started</a>
</small>
</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">Extras</a>
</small>
</div>
<div>
<small>
<a href="../../building.html">Building JiBX</a>
</small>
</div>
<div>
<small>
<a href="../.././jibx-maven-plugin/index.html">Maven</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>
<small>
<a href="../../status.html">News and Status</a>
</small>
</div>
<div>
<small>
<a href="../../support.html">Support</a>
</small>
<div>
<small>
<a href="../../faq.html">FAQ</a>
</small>
</div>
<div>
<small>
<a href="../../mail-lists.html">Mailing Lists</a>
</small>
</div>
<div>
<small>
<a href="../../bugs.html">Bugs</a>
</small>
</div>
</div>
<div>
<small>
<a href="../../comments.html">User Comments</a>
</small>
</div>
<div>
<small>
<a href="../../sponsors.html">Sponsors</a>
</small>
</div>
</div>
<div>
<strong>Start from Code</strong>
<div>
<small>
<a href="../../fromcode/index.html">Start from Code</a>
</small>
</div>
<div>
<small>
<a href="../../fromcode/bindgen.html">BindGen</a>
</small>
<div>
<small>
<a href="../../fromcode/bindgen-examples.html">Example Code</a>
</small>
<div>
<small>
<a href="../../fromcode/bindgen-example1.html">Example 1</a>
</small>
</div>
<div>
<small>
<a href="../../fromcode/bindgen-example2.html">Example 2</a>
</small>
</div>
<div>
<small>
<a href="../../fromcode/bindgen-example3.html">Example 3</a>
</small>
</div>
<div>
<small>
<a href="../../fromcode/bindgen-example4.html">Example 4</a>
</small>
</div>
</div>
<div>
<small>
<a href="../../fromcode/bindgen-customs.html">Customizations Reference</a>
</small>
</div>
</div>
<div>
<small>
<a href="../../fromcode/schemagen.html">SchemaGen</a>
</small>
</div>
<div>
<small>
<a href="../../fromcode/jibx2wsdl.html">Jibx2Wsdl</a>
</small>
<div>
<small>
<a href="../../fromcode/jibx2wsdl-examples.html">Examples</a>
</small>
</div>
<div>
<small>
<a href="../../fromcode/jibx2wsdl-customs.html">Customizations</a>
</small>
</div>
</div>
</div>
<div>
<strong>Start from Schema</strong>
<div>
<small>
<a href="../../fromschema/index.html">Start from Schema</a>
</small>
</div>
<div>
<small>
<a href="../../fromschema/codegen.html">CodeGen</a>
</small>
<div>
<small>
<a href="../../fromschema/codegen-types.html">Schema Datatype Handling</a>
</small>
</div>
<div>
<small>
<a href="../../fromschema/codegen-examples.html">Example Code</a>
</small>
<div>
<small>
<a href="../../fromschema/example-default.html">Default Generation</a>
</small>
</div>
<div>
<small>
<a href="../../fromschema/example-custom1.html">Simple Customizations</a>
</small>
</div>
<div>
<small>
<a href="../../fromschema/example-custom2.html">More Customizations</a>
</small>
</div>
<div>
<small>
<a href="../../fromschema/example-modular.html">Modular Generation</a>
</small>
</div>
</div>
<div>
<small>
<a href="../../fromschema/codegen-customs.html">Customizations Reference</a>
</small>
<div>
<small>
<a href="../../fromschema/codegen-extends.html">Extensions Reference</a>
</small>
</div>
</div>
</div>
</div>
<div>
<strong>Binding Definition</strong>
<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 and arrays</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="../precompiled.html">Precompiled Bindings</a>
</small>
</div>
<div>
<small>
<a href="../binding-overview.html">Definition details</a>
</small>
<div>
<small>
<a href="../contexts.html">Definition contexts</a>
</small>
</div>
<div>
<small>
<a href="../conversions.html">Conversions</a>
</small>
<div>
<small>
<a href="../date-time.html">Date/time conversions</a>
</small>
</div>
</div>
<div>
<small>
<a href="../xml-summary.html">XML summary</a>
</small>
</div>
<div>
<small>
<a href="../binding-element.html"><binding> element</a>
</small>
</div>
<div>
<small>
<a href="../include-element.html"><include> element</a>
</small>
</div>
<div>
<small>
<a href="../format-element.html"><format> element</a>
</small>
</div>
<div>
<small>
<a href="../namespace-element.html"><namespace> element</a>
</small>
</div>
<div>
<small>
<a href="../mapping-element.html"><mapping> element</a>
</small>
</div>
<div>
<small>
<a href="../value-element.html"><value> element</a>
</small>
</div>
<div>
<small>
<a href="../structure-element.html"><structure> element</a>
</small>
</div>
<div>
<small>
<a href="../collection-element.html"><collection> element</a>
</small>
</div>
<div>
<small>
<a href="../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="../../eclipse/index.html">Eclipse Plug-in</a>
</small>
<div>
<small>
<a href="../../eclipse/index.html">Introduction</a>
</small>
</div>
<div>
<small>
<a href="../../eclipse/install.html">Install</a>
</small>
</div>
<div>
<small>
<a href="../../eclipse/usage.html">Usage</a>
</small>
</div>
</div>
<div>
<small>
<a href="../../jibxws/index.html">JiBX/WS</a>
</small>
</div>
<div>
<small>
<a href="../../axis2/index.html">Axis2 Usage</a>
</small>
</div>
<div>
<small>
<a href="../../jibxota/index.html">JiBX/OTA</a>
</small>
</div>
<div>
<small>
<a href="../.././schema-library/index.html">Schema Library</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="../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> © 2003-2011, Dennis M. Sosnoski (<a href="http://www.sosnoski.co.nz">Sosnoski Software Associates Ltd</a>).
Licensed to the JiBX Project for free distribution and use. </td>
</tr>
</tbody>
</table>
</div>
<br>
</body>
</html>
|