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Creating Tuple-Serial Entity Bindings
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Creating Tuple-Serial Entity Bindings
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          <th width="60%" align="center">Chapter 5. 
		Using Tuples
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            <h2 class="title" style="clear: both"><a id="tuple-serialentitybindings"></a>
Creating Tuple-Serial Entity Bindings
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      <p>
In the prior example serial keys and serial values were used,
and the 
<a href="../../java/com/sleepycat/bind/serial/SerialSerialBinding.html" target="_top">SerialSerialBinding</a>

base class was used for entity bindings. In this example, tuple
keys and serial values are used and therefore the 
<a href="../../java/com/sleepycat/bind/serial/TupleSerialBinding.html" target="_top">TupleSerialBinding</a>

base class is used for entity bindings.
</p>
      <p>
As with any entity binding, a key and value is converted to an
entity in the 
<a href="../../java/com/sleepycat/bind/serial/TupleSerialBinding.html#entryToObject(com.sleepycat.bind.tuple.TupleInput,%20java.lang.Object)" target="_top">TupleSerialBinding.entryToObject</a>

method, and from an entity to
a key and value in the 
<a href="../../java/com/sleepycat/bind/serial/TupleSerialBinding.html#objectToKey(java.lang.Object,%20com.sleepycat.db.DatabaseEntry)" target="_top">TupleSerialBinding.objectToKey</a>

and 
<a href="../../java/com/sleepycat/bind/serial/TupleSerialBinding.html#objectToData(java.lang.Object)" target="_top">TupleSerialBinding.objectToData</a>

methods. But since keys are
stored as tuples, not as serialized objects, key fields are read
and written using the 
<a href="../../java/com/sleepycat/bind/tuple/TupleInput.html" target="_top">TupleInput</a>

and 
<a href="../../java/com/sleepycat/bind/tuple/TupleOutput.html" target="_top">TupleOutput</a>

parameters.
</p>
      <p>
The <tt class="classname">SampleViews</tt> class contains the modified entity
binding classes that were defined in the prior example:
<tt class="classname">PartBinding</tt>, <tt class="classname">SupplierBinding</tt> and
<tt class="classname">ShipmentBinding</tt>.
</p>
      <a id="tuple_partbinding"></a>
      <pre class="programlisting"><b class="userinput"><tt>import com.sleepycat.bind.serial.TupleSerialBinding;
import com.sleepycat.bind.tuple.TupleInput;
import com.sleepycat.bind.tuple.TupleOutput;
...</tt></b>
public class SampleViews
{
    ...
    private static class PartBinding extends <b class="userinput"><tt>TupleSerialBinding</tt></b> 
    {
        private PartBinding(ClassCatalog classCatalog, <b class="userinput"><tt>Class dataClass</tt></b>)
        {
            super(classCatalog, dataClass);
        }
        public Object entryToObject(<b class="userinput"><tt>TupleInput</tt></b> keyInput, Object dataInput)
        {
<b class="userinput"><tt>            String number = keyInput.readString();</tt></b>
            PartData data = (PartData) dataInput;
            return new Part(<b class="userinput"><tt>number</tt></b>, data.getName(), data.getColor(),
                            data.getWeight(), data.getCity());
        }
        public void objectToKey(Object object, TupleOutput output)
        {
            Part part = (Part) object;
<b class="userinput"><tt>            output.writeString(part.getNumber());</tt></b>
        }
        public Object objectToData(Object object)
        {
            Part part = (Part) object;
            return new PartData(part.getName(), part.getColor(),
                                 part.getWeight(), part.getCity());
        }
    }
    ...
    private static class SupplierBinding extends <b class="userinput"><tt>TupleSerialBinding</tt></b>
    {
        private SupplierBinding(ClassCatalog classCatalog, <b class="userinput"><tt>Class dataClass</tt></b>)
        {
            super(classCatalog, dataClass);
        }
        public Object entryToObject(<b class="userinput"><tt>TupleInput</tt></b> keyInput, Object dataInput)
        {
<b class="userinput"><tt>            String number = keyInput.readString();</tt></b>
            SupplierData data = (SupplierData) dataInput;
            return new Supplier(<b class="userinput"><tt>number</tt></b>, data.getName(),
                                data.getStatus(), data.getCity());
        }
        public void objectToKey(Object object, TupleOutput output)
        {
            Supplier supplier = (Supplier) object;
<b class="userinput"><tt>            output.writeString(supplier.getNumber());</tt></b>
        }
        public Object objectToData(Object object)
        {
            Supplier supplier = (Supplier) object;
            return new SupplierData(supplier.getName(), supplier.getStatus(),
                                     supplier.getCity());
        }
    }
    ...
    private static class ShipmentBinding extends <b class="userinput"><tt>TupleSerialBinding</tt></b>
    {
        private ShipmentBinding(ClassCatalog classCatalog, <b class="userinput"><tt>Class dataClass</tt></b>)
        {
            super(classCatalog, dataClass);
        }
        public Object entryToObject(<b class="userinput"><tt>TupleInput</tt></b> keyInput, Object dataInput)
        {
<b class="userinput"><tt>            String partNumber = keyInput.readString();
            String supplierNumber = keyInput.readString();</tt></b>
            ShipmentData data = (ShipmentData) dataInput;
            return new Shipment(<b class="userinput"><tt>partNumber, supplierNumber</tt></b>,
                                data.getQuantity());
        }
        public void objectToKey(Object object, TupleOutput output)
        {
            Shipment shipment = (Shipment) object;
<b class="userinput"><tt>            output.writeString(shipment.getPartNumber());
            output.writeString(shipment.getSupplierNumber());</tt></b>
        }
        public Object objectToData(Object object)
        {
            Shipment shipment = (Shipment) object;
            return new ShipmentData(shipment.getQuantity());
        }
    }
    ...
} </pre>
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