mirror of
https://github.com/berkeleydb/je.git
synced 2024-11-15 01:46:24 +00:00
120 lines
4.8 KiB
HTML
120 lines
4.8 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
|
|||
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|||
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|||
|
|
<head>
|
|||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
|
|||
|
|
<title>DataAccessor.java</title>
|
|||
|
|
<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
|
|||
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
|
|||
|
|
<link rel="start" href="index.html" title="Getting Started with Berkeley DB Java Edition" />
|
|||
|
|
<link rel="up" href="dpl_example.html" title="Chapter 6. A DPL Example" />
|
|||
|
|
<link rel="prev" href="mydbenv-persist.html" title="MyDbEnv" />
|
|||
|
|
<link rel="next" href="dpl_exampledatabaseput.html" title="ExampleDatabasePut.java" />
|
|||
|
|
</head>
|
|||
|
|
<body>
|
|||
|
|
<div xmlns="" class="navheader">
|
|||
|
|
<div class="libver">
|
|||
|
|
<p>Library Version 12.2.7.5</p>
|
|||
|
|
</div>
|
|||
|
|
<table width="100%" summary="Navigation header">
|
|||
|
|
<tr>
|
|||
|
|
<th colspan="3" align="center">DataAccessor.java</th>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="20%" align="left"><a accesskey="p" href="mydbenv-persist.html">Prev</a> </td>
|
|||
|
|
<th width="60%" align="center">Chapter 6. A DPL Example</th>
|
|||
|
|
<td width="20%" align="right"> <a accesskey="n" href="dpl_exampledatabaseput.html">Next</a></td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
<hr />
|
|||
|
|
</div>
|
|||
|
|
<div class="sect1" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h2 class="title" style="clear: both"><a id="dataaccessorclass"></a>DataAccessor.java</h2>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
Now that we have implemented our data classes,
|
|||
|
|
we can write a class that will provide
|
|||
|
|
convenient access to our primary and
|
|||
|
|
secondary indexes.
|
|||
|
|
Note that like our data classes, this class is shared by both our
|
|||
|
|
example programs.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
If you compare this class against our
|
|||
|
|
<code class="classname">Vendor</code> and
|
|||
|
|
<code class="classname">Inventory</code>
|
|||
|
|
class implementations, you will see that the
|
|||
|
|
primary and secondary indices declared there are
|
|||
|
|
referenced by this class.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
See <a class="xref" href="dpl_example.html#vendorclass" title="Vendor.java">Vendor.java</a>
|
|||
|
|
and
|
|||
|
|
<a class="xref" href="inventoryclass.html" title="Inventory.java">Inventory.java</a>
|
|||
|
|
for those implementations.
|
|||
|
|
</p>
|
|||
|
|
<pre class="programlisting">package persist.gettingStarted;
|
|||
|
|
|
|||
|
|
import java.io.File;
|
|||
|
|
|
|||
|
|
import com.sleepycat.je.DatabaseException;
|
|||
|
|
import com.sleepycat.persist.EntityStore;
|
|||
|
|
import com.sleepycat.persist.PrimaryIndex;
|
|||
|
|
import com.sleepycat.persist.SecondaryIndex;
|
|||
|
|
|
|||
|
|
public class DataAccessor {
|
|||
|
|
// Open the indices
|
|||
|
|
public DataAccessor(EntityStore store)
|
|||
|
|
throws DatabaseException {
|
|||
|
|
|
|||
|
|
// Primary key for Inventory classes
|
|||
|
|
inventoryBySku = store.getPrimaryIndex(
|
|||
|
|
String.class, Inventory.class);
|
|||
|
|
|
|||
|
|
// Secondary key for Inventory classes
|
|||
|
|
// Last field in the getSecondaryIndex() method must be
|
|||
|
|
// the name of a class member; in this case, an Inventory.class
|
|||
|
|
// data member.
|
|||
|
|
inventoryByName = store.getSecondaryIndex(
|
|||
|
|
inventoryBySku, String.class, "itemName");
|
|||
|
|
|
|||
|
|
// Primary key for Vendor class
|
|||
|
|
vendorByName = store.getPrimaryIndex(
|
|||
|
|
String.class, Vendor.class);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Inventory Accessors
|
|||
|
|
PrimaryIndex<String,Inventory> inventoryBySku;
|
|||
|
|
SecondaryIndex<String,String,Inventory> inventoryByName;
|
|||
|
|
|
|||
|
|
// Vendor Accessors
|
|||
|
|
PrimaryIndex<String,Vendor> vendorByName;
|
|||
|
|
} </pre>
|
|||
|
|
</div>
|
|||
|
|
<div class="navfooter">
|
|||
|
|
<hr />
|
|||
|
|
<table width="100%" summary="Navigation footer">
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left"><a accesskey="p" href="mydbenv-persist.html">Prev</a> </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="u" href="dpl_example.html">Up</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right"> <a accesskey="n" href="dpl_exampledatabaseput.html">Next</a></td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left" valign="top">MyDbEnv </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="h" href="index.html">Home</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right" valign="top"> ExampleDatabasePut.java</td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
</div>
|
|||
|
|
</body>
|
|||
|
|
</html>
|