Skip to main content
summaryrefslogtreecommitdiffstats
blob: e056541d5ef0d9ae85b66277873e3fe012d90372 (plain) (blame)
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
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta content="Apache Forrest" name="Generator">
<meta name="Forrest-version" content="0.7">
<meta name="Forrest-skin-name" content="elver4">
<style type="text/css">
          /*  */
          @import "../../skin/tigris.css";
          @import "../../skin/quirks.css";
          @import "../../skin/inst.css";
         /*   */
        </style>
<link media="print" href="../../skin/print.css" type="text/css" rel="stylesheet">
<link href="../../skin/forrest.css" type="text/css" rel="stylesheet">
<link rel="shortcut icon" href="../../">
<script type="text/javascript" src="../../skin/tigris.js"></script><script src="../../skin/menu.js" language="javascript" type="text/javascript"></script>
<title>Step 3: Retrieve and add EMF Objects</title>
<meta content="text/css" http-equiv="Content-style-type">
</head>
<body class="composite" onload="focus()">
<div id="banner">
<table width="100%" cellpadding="8" cellspacing="0" border="0">
<tr>
<td align="left">
<div>
<a href="http://www.elver.org"><img class="logoImage" alt="Elver Store" src="../../images/ELV2.gif"></a>
</div>
<span class="alt">Elver Store</span></td><td align="center">
<div>
<a href="http://www.elver.org/"><img class="logoImage" alt="Elver" src="../../images/empty.gif"></a>
</div>
</td><td valign="top" align="right">
<div class="right" align="right" id="login">
<form target="_blank" action="http://www.google.com/search" method="get">
<select name="as_sitesearch"><option value="">Search...</option><option value="www.elver.org">The elver site</option><option value="">The web</option></select> for
		      <input size="15" name="as_q" id="query" type="text"><input name="Search" value="Go" type="submit">
</form>
</div>
</td>
</tr>
</table>
</div>
<div id="toptabs" class="tabs">
<table border="0" cellspacing="0" cellpadding="4">
<tr>
<td><a class="base-selected" href="../../index.html">Home</a></td><td><a class="base-selected" href="../../hibernate/index.html">EMF Hibernate</a></td><th><a class="base-selected" href="../../jpox/index.html">EMF JDO/JPOX</a></th><td><a class="base-selected" href="../../services/index.html">Services</a></td>
</tr>
</table>
</div>
<table width="100%" border="0" cellpadding="0" cellspacing="0" id="breadcrumbs">
<tr>
<td></td><td>
<div class="published" align="right">
<script type="text/javascript" language="JavaScript"><!--
                 document.write("Published: " + document.lastModified);
                 //  --></script>
</div>
</td>
</tr>
</table>
<table id="main" width="100%" cellpadding="4" cellspacing="0" border="0">
<tr valign="top">
<td style="padding: 0px" width="20%" id="leftcol">
<table width="100%" class="menuarea" cellspacing="0" cellpadding="0">
<tr>
<td width="6px" valign="top">
<table border="0" cellpadding="0" cellspacing="0" class="leftpagemargin">
<tr>
<td class="subborder trail">&nbsp;</td>
</tr>
</table>
</td><td class="dialog">
<div class="menu">
<div onclick="SwitchMenu('menu_1.1')" id="menu_1.1Title" class="menutitle">Home</div>
<div id="menu_1.1" class="menuitemgroup">
<div class="menuitem">
<a href="../../jpox/index.html">Introduction</a>
</div>
<div class="menuitem">
<a href="../../jpox/features.html">Features</a>
</div>
<div class="menuitem">
<a href="../../jpox/status.html">Status</a>
</div>
<div class="menuitem">
<a href="../../jpox/overview.html">Overview</a>
</div>
<div class="menuitem">
<a href="../../jpox/changelog.html">Changelog</a>
</div>
<div class="menuitem">
<a href="../../jpox/installation.html">Download &amp; Install</a>
</div>
<div class="menuitem">
<a href="../../jpox/knownissues.html">Known Issues</a>
</div>
<div class="menuitem">
<a href="../../jpox/quick_tutorial.html">Quick Start</a>
</div>
<div class="menuitem">
<a href="../../jpox/license.html">License</a>
</div>
</div>
<div onclick="SwitchMenu('menu_selected_1.2')" id="menu_selected_1.2Title" class="menutitle">Library Tutorial</div>
<div id="menu_selected_1.2" class="selectedmenuitemgroup">
<div class="menuitem">
<a href="../../jpox/tutorial1/tutorial1_intro.html">Introduction</a>
</div>
<div class="menuitem">
<a href="../../jpox/tutorial1/tutorial1_1.html">Generate OR Mapping File</a>
</div>
<div class="menuitem">
<a href="../../jpox/tutorial1/tutorial1_2.html">Create and Store EMF Object</a>
</div>
<div class="menupage">
<div class="menupagetitle">Retrieve EMF Objects</div>
</div>
<div class="menuitem">
<a href="../../jpox/tutorial1/tutorial1_4.html">Query EMF Objects</a>
</div>
<div class="menuitem">
<a href="../../jpox/tutorial1/tutorial1_5.html">Using EMF/JPOX Resources</a>
</div>
</div>
<div onclick="SwitchMenu('menu_1.3')" id="menu_1.3Title" class="menutitle">Library Editor tutorial</div>
<div id="menu_1.3" class="menuitemgroup">
<div class="menuitem">
<a href="../../jpox/tutorial2/tutorial2_intro.html">Introduction</a>
</div>
<div class="menuitem">
<a href="../../jpox/tutorial2/tutorial2_1.html">Initialize the Library Editor</a>
</div>
<div class="menuitem">
<a href="../../jpox/tutorial2/tutorial2_2.html">Run the Library Editor</a>
</div>
</div>
<div onclick="SwitchMenu('menu_1.4')" id="menu_1.4Title" class="menutitle">Details</div>
<div id="menu_1.4" class="menuitemgroup">
<div class="menuitem">
<a href="../../jpox/inheritance.html">Inheritance Mapping</a>
</div>
<div class="menuitem">
<a href="../../jpox/jpox_details.html">JPOX Details</a>
</div>
<div class="menuitem">
<a href="../../jpox/jpoxresources.html">EMF/JPOX Resources</a>
</div>
<div class="menuitem">
<a href="../../jpox/resource_utility.html">Resource Utility</a>
</div>
<div class="menuitem">
<a href="../../jpox/jpoxdatastore.html">JpoxDataStore</a>
</div>
<div class="menuitem">
<a href="../../jpox/troubleshooting.html">Troubleshooting</a>
</div>
</div>
<div onclick="SwitchMenu('menu_1.5')" id="menu_1.5Title" class="menutitle">Annotations (JPA/EJB3)</div>
<div id="menu_1.5" class="menuitemgroup">
<div class="menuitem">
<a href="../../jpox/ejb3_features.html">Supported Ann.</a>
</div>
<div class="menuitem">
<a href="../../jpox/ejb3_format.html">EAnn. Format</a>
</div>
<div class="menuitem">
<a href="../../jpox/ejb3_examples.html">EAnn. Examples</a>
</div>
</div>
<div onclick="SwitchMenu('menu_1.6')" id="menu_1.6Title" class="menutitle">XML Schema</div>
<div id="menu_1.6" class="menuitemgroup">
<div class="menuitem">
<a href="../../jpox/features_details.html">XML Schema Features</a>
</div>
<div class="menuitem">
<a href="../../jpox/featuremap.html">Feature Map/Mixed Content</a>
</div>
<div class="menuitem">
<a href="../../jpox/substitution.html">Substitution Group</a>
</div>
<div class="menuitem">
<a href="../../jpox/anytype.html">xsd:any/xsd:anyType</a>
</div>
<div class="menuitem">
<a href="../../jpox/schema_list.html">XML Schema Examples</a>
</div>
</div>
<div onclick="SwitchMenu('menu_1.7')" id="menu_1.7Title" class="menutitle">Support</div>
<div id="menu_1.7" class="menuitemgroup">
<div class="menuitem">
<a href="../../jpox/upgrading.html">Upgrading</a>
</div>
<div class="menuitem">
<a href="../../jpox/mailinglist.html">Newsgroup</a>
</div>
<div class="menuitem">
<a href="../../jpox/emfjpoxsupport.html">EMF/JPOX Support</a>
</div>
</div>
<div onclick="SwitchMenu('menu_1.8')" id="menu_1.8Title" class="menutitle">Developer</div>
<div id="menu_1.8" class="menuitemgroup">
<div class="menuitem">
<a href="../../jpox/svn.html">CVS</a>
</div>
</div>
</div>
</td>
</tr>
<tr>
<td></td><td>
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td class="border bottom-left"></td><td class="border bottomborder"></td><td class="border bottom-right"></td>
</tr>
</table>
</td>
</tr>
<tr>
<td colspan="2" height="10"></td>
</tr>
</table>
<table></table>
<table></table>
<div class="strut">&nbsp;</div>
</td><td>
<div class="content">
<div id="bodycol">
<div id="apphead">
<h2>
<em>Step 3: Retrieve and add EMF Objects</em>
</h2>
</div>
<div class="app" id="projecthome">
<ul class="minitoc">
<li>
<a href="#Retrieve+Library+EMF+Object">Retrieve Library EMF Object</a>
</li>
<li>
<a href="#Do+some+checks">Do some checks</a>
</li>
<li>
<a href="#Add+a+new+book+and+writer">Add a new book and writer</a>
</li>
<li>
<a href="#Next+Step">Next Step</a>
</li>
</ul>
		
<p>In this step the library is retrieved from the backend and a few checks are done on the 
			retrieved EMF objects. In addition a new book and writer are added to the library.</p>
		
<a name="N10011"></a><a name="Retrieve+Library+EMF+Object"></a>
<div class="h3">
<h3>Retrieve Library EMF Object</h3>
			
		
<p>In this part of the tutorial the library object is retrieved.</p>
		
<pre class="code">
// at this point the database contains one library, one book and one writer
// Reopen the transaction and query for the library objects
pm = jpoxDataStore.getPersistenceManager();
tx = pm.currentTransaction(); 
tx.begin();
	
// NOTE: for querying you require the concrete implementation instead of the
// interface!
// retrieve all LibraryImpl classes and subclasses.
Extent e = pm.getExtent(LibraryImpl.class, true);
Query q = pm.newQuery(e);

// there is only one library
Collection c = (Collection)q.execute();
lib = (Library)c.iterator().next();
</pre>
	
</div>
	
<a name="N1001F"></a><a name="Do+some+checks"></a>
<div class="h3">
<h3>Do some checks</h3>
		
		
<p>The library object has been retrieved now a few checks are done to ensure that the correct
			information was retrieved.</p>
		
<pre class="code">
// read the writer and book
writer = (Writer)lib.getWriters().get(0);
System.out.println(writer.getName());
book = (Book)lib.getBooks().get(0);
System.out.println(book.getTitle());

// show that the container is set
System.out.println(book.eContainer() == lib);
System.out.println(writer.getBooks().get(0) == book);
	</pre>
	
</div>	
	
<a name="N1002D"></a><a name="Add+a+new+book+and+writer"></a>
<div class="h3">
<h3>Add a new book and writer</h3>
		
		
<p>Here a new book and writer are added to the library.</p>
		
<pre class="code">
// Now add a new writer and book
Writer george = LibraryFactory.eINSTANCE.createWriter();
george.setName("G. Orwell");

// create a new book and set the writer and library
Book georgesBook = LibraryFactory.eINSTANCE.createBook();
georgesBook.setPages(250);
georgesBook.setTitle("1984");
georgesBook.setCategory(BookCategory.SCIENCE_FICTION_LITERAL);
georgesBook.setAuthor(george);

lib.getBooks().add(georgesBook);
lib.getWriters().add(george);

// and close of
tx.commit();
pm.close();
	</pre>
	
</div>	
			
<a name="N1003B"></a><a name="Next+Step"></a>
<div class="h3">
<h3>Next Step</h3>
		
		
<p>The final step in the tutorial shows some JDO queries to retrieve EMF objects from the library.
			</p>
		
<p>Please click <a href="tutorial1_4.html">here</a> to go to the next step.</p>
	
</div>	

	
</div>
</div>
</div>
</td>
</tr>
</table>
<div width="100%" id="footer">
<table width="100%" cellpadding="4" cellspacing="0" border="0">
<tr>
<td class="footer"><a href="license.html">
          Copyright &copy; 2007 The Elver Project</a>
      - All rights reserved.
      </td>
</tr>
</table>
</div>
</body>
</html>

Back to the top