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<h2 class="title" style="clear: both"><a id="simpleput"></a>Placing Objects in an Entity Store</h2>
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<p>
In order to place an object in a DPL entity store,
you must:
</p>
<div class="orderedlist">
<ol type="1">
<li>
<p>
Open the environment and store.
</p>
</li>
<li>
<p>
Instantiate the object.
</p>
</li>
<li>
<p>
Put the object to the store using the
<tt class="methodname">put()</tt> method
for the object's primary index.
</p>
</li>
</ol>
</div>
<p>
The following example uses the <tt class="classname">SimpleDA</tt>
class that we show in <a href="simpleda.html">SimpleDA.class</a> to put a
<tt class="classname">SimpleEntityClass</tt> object (see
<a href="persist_access.html#simpleentity">A Simple Entity Class</a>) to the
entity store.
</p>
<p>
To begin, we import the Java classes that our example
needs. We also instantiate the private data members that we
require.
</p>
<pre class="programlisting">package persist.gettingStarted;
import java.io.File;
import java.io.FileNotFoundException;
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.Environment;
import com.sleepycat.db.EnvironmentConfig;
import com.sleepycat.persist.EntityStore;
import com.sleepycat.persist.StoreConfig;
public class SimpleStorePut {
private static File envHome = new File("./JEDB");
private Environment envmnt;
private EntityStore store;
private SimpleDA sda; </pre>
<p>
Next we create a method that simply opens our database
environment and entity store for us.
</p>
<pre class="programlisting"> // The setup() method opens the environment and store
// for us.
public void setup()
throws DatabaseException {
EnvironmentConfig envConfig = new EnvironmentConfig();
StoreConfig storeConfig = new StoreConfig();
envConfig.setAllowCreate(true);
storeConfig.setAllowCreate(true);
try {
// Open the environment and entity store
envmnt = new Environment(envHome, envConfig);
store = new EntityStore(envmnt, "EntityStore", storeConfig);
} catch (FileNotFoundException fnfe) {
System.err.println("setup(): " + fnfe.toString());
System.exit(-1);
}
} </pre>
<p>
We also need a method to close our environment and store.
</p>
<pre class="programlisting"> // Close our environment and store.
public void shutdown()
throws DatabaseException {
store.close();
envmnt.close();
} </pre>
<p>
Now we need to create a method to actually write objects to our
store. This method creates a <tt class="classname">SimpleDA</tt>
object (see <a href="simpleda.html">SimpleDA.class</a> that we
will use to access our indexes. Then we instantiate a serious
of <tt class="classname">SimpleEntityClass</tt> (see <a href="persist_access.html#simpleentity">A Simple Entity Class</a>)
instances that we
will place in our store. Finally, we use our primary index
(obtained from the <tt class="classname">SimpleDA</tt> class
instance) to actually place these objects in our store.
</p>
<p>
In <a href="simpleget.html">Retrieving Objects from an Entity Store</a>
we show a class that is used to retrieve these objects.
</p>
<pre class="programlisting"> // Populate the entity store
private void run()
throws DatabaseException {
setup();
// Open the data accessor. This is used to store
// persistent objects.
sda = new SimpleDA(store);
// Instantiate and store some entity classes
SimpleEntityClass sec1 = new SimpleEntityClass();
SimpleEntityClass sec2 = new SimpleEntityClass();
SimpleEntityClass sec3 = new SimpleEntityClass();
SimpleEntityClass sec4 = new SimpleEntityClass();
SimpleEntityClass sec5 = new SimpleEntityClass();
sec1.setpKey("keyone");
sec1.setsKey("skeyone");
sec2.setpKey("keytwo");
sec2.setsKey("skeyone");
sec3.setpKey("keythree");
sec3.setsKey("skeytwo");
sec4.setpKey("keyfour");
sec4.setsKey("skeythree");
sec5.setpKey("keyfive");
sec5.setsKey("skeyfour");
sda.pIdx.put(sec1);
sda.pIdx.put(sec2);
sda.pIdx.put(sec3);
sda.pIdx.put(sec4);
sda.pIdx.put(sec5);
shutdown();
} </pre>
<p>
Finally, to complete our class, we need a
<tt class="methodname">main()</tt> method, which simply calls our
<tt class="methodname">run()</tt> method.
</p>
<pre class="programlisting"> // main
public static void main(String args[]) {
SimpleStorePut ssp = new SimpleStorePut();
try {
ssp.run();
} catch (DatabaseException dbe) {
System.err.println("SimpleStorePut: " + dbe.toString());
dbe.printStackTrace();
} catch (Exception e) {
System.out.println("Exception: " + e.toString());
e.printStackTrace();
}
System.out.println("All done.");
}
} </pre>
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