Berkeley DB Reference Guide: Tuple - Using sorted collections

Berkeley DB Reference Guide:
Java API Tutorial - Tuple

Tuple - Using sorted collections

In general, no changes to the prior example are necessary to use collections having tuple keys. Iteration of elements in a stored collection will be ordered by the sort order of the tuples. In addition to using the tuple format, the Db.DB_BTREE access method must be used when creating the database. Db.DB_BTREE is used for the databases in all examples. The Db.DB_HASH access method does not support sorted keys.

Although not shown in the example, all methods of the SortedMap and SortedSet interfaces may be used with sorted collections. For example, submaps and subsets may be created.

To create a sorted collection, the StoredSortedMap class is used instead of StoredMap .

import com.sleepycat.bdb.collection.StoredSortedMap;
...
public class SampleViews
{
    private StoredSortedMap partMap;
    private StoredSortedMap supplierMap;
    private StoredSortedMap shipmentMap;
    private StoredSortedMap shipmentByPartMap;
    private StoredSortedMap shipmentBySupplierMap;
    private StoredSortedMap supplierByCityMap;
    ...
    public SampleViews(SampleDatabase db)
    {
        ...
        partMap =
            new StoredSortedMap(db.getPartStore(),
                          partKeyBinding, partValueBinding, true);
        supplierMap =
            new StoredSortedMap(db.getSupplierStore(),
                          supplierKeyBinding, supplierValueBinding, true);
        shipmentMap =
            new StoredSortedMap(db.getShipmentStore(),
                          shipmentKeyBinding, shipmentValueBinding, true);
        shipmentByPartMap =
            new StoredSortedMap(db.getShipmentByPartIndex(),
                          partKeyBinding, shipmentValueBinding, true);
        shipmentBySupplierMap =
            new StoredSortedMap(db.getShipmentBySupplierIndex(),
                          supplierKeyBinding, shipmentValueBinding, true);
        supplierByCityMap =
            new StoredSortedMap(db.getSupplierByCityIndex(),
                          cityKeyBinding, supplierValueBinding, true);
    }
}

The getter methods of SampleViews also return StoredSortedMap and, as a convenience, StoredSortedValueSet .

import com.sleepycat.bdb.collection.StoredSortedMap;
import com.sleepycat.bdb.collection.StoredSortedValueSet;
...
public class SampleViews
{
    ...
    public StoredSortedMap getPartMap()
    {
        return partMap;
    }

    public StoredSortedMap getSupplierMap()
    {
        return supplierMap;
    }

    public StoredSortedMap getShipmentMap()
    {
        return shipmentMap;
    }

    public StoredSortedValueSet getPartSet()
    {
        return (StoredSortedValueSet) partMap.values();
    }

    public StoredSortedValueSet getSupplierSet()
    {
        return (StoredSortedValueSet) supplierMap.values();
    }

    public StoredSortedValueSet getShipmentSet()
    {
        return (StoredSortedValueSet) shipmentMap.values();
    }

    public StoredSortedMap getShipmentByPartMap()
    {
        return shipmentByPartMap;
    }

    public StoredSortedMap getShipmentBySupplierMap()
    {
        return shipmentBySupplierMap;
    }

    public final StoredSortedMap getSupplierByCityMap()
    {
        return supplierByCityMap;
    }
    ...
}

The output of the example program shows that records are sorted by key value.

Adding Suppliers
Adding Parts
Adding Shipments

--- Parts ---
Part: number=P1 name=Nut color=Red weight=[12.0 grams] city=London
Part: number=P2 name=Bolt color=Green weight=[17.0 grams] city=Paris
Part: number=P3 name=Screw color=Blue weight=[17.0 grams] city=Rome
Part: number=P4 name=Screw color=Red weight=[14.0 grams] city=London
Part: number=P5 name=Cam color=Blue weight=[12.0 grams] city=Paris
Part: number=P6 name=Cog color=Red weight=[19.0 grams] city=London

--- Suppliers ---
Supplier: number=S1 name=Smith status=20 city=London
Supplier: number=S2 name=Jones status=10 city=Paris
Supplier: number=S3 name=Blake status=30 city=Paris
Supplier: number=S4 name=Clark status=20 city=London
Supplier: number=S5 name=Adams status=30 city=Athens

--- Suppliers for City Paris ---
Supplier: number=S2 name=Jones status=10 city=Paris
Supplier: number=S3 name=Blake status=30 city=Paris

--- Shipments ---
Shipment: part=P1 supplier=S1 quantity=300
Shipment: part=P1 supplier=S2 quantity=300
Shipment: part=P2 supplier=S1 quantity=200
Shipment: part=P2 supplier=S2 quantity=400
Shipment: part=P2 supplier=S3 quantity=200
Shipment: part=P2 supplier=S4 quantity=200
Shipment: part=P3 supplier=S1 quantity=400
Shipment: part=P4 supplier=S1 quantity=200
Shipment: part=P4 supplier=S4 quantity=300
Shipment: part=P5 supplier=S1 quantity=100
Shipment: part=P5 supplier=S4 quantity=400
Shipment: part=P6 supplier=S1 quantity=100

--- Shipments for Part P1 ---
Shipment: part=P1 supplier=S1 quantity=300
Shipment: part=P1 supplier=S2 quantity=300

--- Shipments for Supplier S1 ---
Shipment: part=P1 supplier=S1 quantity=300
Shipment: part=P2 supplier=S1 quantity=200
Shipment: part=P3 supplier=S1 quantity=400
Shipment: part=P4 supplier=S1 quantity=200
Shipment: part=P5 supplier=S1 quantity=100
Shipment: part=P6 supplier=S1 quantity=100

Berkeley DB Reference Guide:Java API Tutorial - Tuple

Tuple - Using sorted collections

Berkeley DB Reference Guide:
Java API Tutorial - Tuple