Table of Contents
To store an object in an EntityStore you
must annotate the class appropriately and then store it using
PrimaryIndex.put().
To retrieve and object from an EntityStore
you use the get() method from either the
PrimaryIndex or
SecondaryIndex, whichever is most
appropriate for your application.
In both cases, it simplifies things greatly if you create a data accessor class to organize your indexes.
In the next few sections we:
Create an entity class that is ready to be stored in an entity store. This class will have both a primary index (required) declared for it, as well as a secondary index (which is optional).
See the next section for this implementation.
Create a data accessor class which is used to organize our data.
See SimpleDA.class for this implementation.
Create a simple class that is used to put objects to our entity store.
See Placing Objects in an Entity Store for this implementation.
Create another class that retrieves objects from our entity store.
See Retrieving Objects from an Entity Store for this implementation.
For clarity's sake, this entity class is a simple a class as we can write. It contains only two data members, both of which are set and retrieved by simple setter and getter methods. Beyond that, by design this class does not do anything or particular interest.
Its implementation is as follows:
package persist.gettingStarted;
import com.sleepycat.persist.model.Entity;
import com.sleepycat.persist.model.PrimaryKey;
import static com.sleepycat.persist.model.Relationship.*;
import com.sleepycat.persist.model.SecondaryKey;
@Entity
public class SimpleEntityClass {
// Primary key is pKey
@PrimaryKey
private String pKey;
// Secondary key is the sKey
@SecondaryKey(relate=MANY_TO_ONE)
private String sKey;
public void setPKey(String data) {
pKey = data;
}
public void setSKey(String data) {
sKey = data;
}
public String getPKey() {
return pKey;
}
public String getSKey() {
return sKey;
}
}