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8.5 KiB
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<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
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<title>Creating Tuple-Serial Entity Bindings</title>
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<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
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<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
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<link rel="start" href="index.html" title="Berkeley DB Collections Tutorial" />
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<link rel="up" href="Tuple.html" title="Chapter 5. Using Tuples" />
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<link rel="prev" href="tuplekeybindings.html" title="Creating Tuple Key Bindings" />
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<link rel="next" href="sortedcollections.html" title="Using Sorted Collections" />
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</head>
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<body>
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<div xmlns="" class="navheader">
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<div class="libver">
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<p>Library Version 11.2.5.2</p>
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</div>
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<table width="100%" summary="Navigation header">
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<tr>
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<th colspan="3" align="center">
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Creating Tuple-Serial Entity Bindings
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</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="tuplekeybindings.html">Prev</a> </td>
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<th width="60%" align="center">Chapter 5.
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Using Tuples
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</th>
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<td width="20%" align="right"> <a accesskey="n" href="sortedcollections.html">Next</a></td>
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</tr>
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</table>
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<hr />
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</div>
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<div class="sect1" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h2 class="title" style="clear: both"><a id="tuple-serialentitybindings"></a>
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Creating Tuple-Serial Entity Bindings
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</h2>
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</div>
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</div>
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</div>
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<p>
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In the prior example serial keys and serial values were used,
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and the
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<a class="ulink" href="../../java/com/sleepycat/bind/serial/SerialSerialBinding.html" target="_top">SerialSerialBinding</a>
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base class was used for entity bindings. In this example, tuple
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keys and serial values are used and therefore the
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<a class="ulink" href="../../java/com/sleepycat/bind/serial/TupleSerialBinding.html" target="_top">TupleSerialBinding</a>
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base class is used for entity bindings.
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</p>
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<p>
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As with any entity binding, a key and value is converted to an
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entity in the
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<a class="ulink" href="../../java/com/sleepycat/bind/serial/TupleSerialBinding.html#entryToObject(com.sleepycat.bind.tuple.TupleInput,%20java.lang.Object)" target="_top">TupleSerialBinding.entryToObject</a>
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method, and from an entity to
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a key and value in the
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<a class="ulink" href="../../java/com/sleepycat/bind/serial/TupleSerialBinding.html#objectToKey(java.lang.Object,%20com.sleepycat.db.DatabaseEntry)" target="_top">TupleSerialBinding.objectToKey</a>
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and
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<a class="ulink" href="../../java/com/sleepycat/bind/serial/TupleSerialBinding.html#objectToData(java.lang.Object)" target="_top">TupleSerialBinding.objectToData</a>
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methods. But since keys are
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stored as tuples, not as serialized objects, key fields are read
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and written using the
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<a class="ulink" href="../../java/com/sleepycat/bind/tuple/TupleInput.html" target="_top">TupleInput</a>
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and
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<a class="ulink" href="../../java/com/sleepycat/bind/tuple/TupleOutput.html" target="_top">TupleOutput</a>
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parameters.
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</p>
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<p>
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The <code class="classname">SampleViews</code> class contains the modified entity
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binding classes that were defined in the prior example:
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<code class="classname">PartBinding</code>, <code class="classname">SupplierBinding</code> and
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<code class="classname">ShipmentBinding</code>.
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</p>
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<a id="tuple_partbinding"></a>
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<pre class="programlisting"><strong class="userinput"><code>import com.sleepycat.bind.serial.TupleSerialBinding;
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import com.sleepycat.bind.tuple.TupleInput;
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import com.sleepycat.bind.tuple.TupleOutput;
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...</code></strong>
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public class SampleViews
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{
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...
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private static class PartBinding extends <strong class="userinput"><code>TupleSerialBinding</code></strong>
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{
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private PartBinding(ClassCatalog classCatalog, <strong class="userinput"><code>Class dataClass</code></strong>)
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{
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super(classCatalog, dataClass);
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}
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public Object entryToObject(<strong class="userinput"><code>TupleInput</code></strong> keyInput, Object dataInput)
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{
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<strong class="userinput"><code> String number = keyInput.readString();</code></strong>
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PartData data = (PartData) dataInput;
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return new Part(<strong class="userinput"><code>number</code></strong>, data.getName(), data.getColor(),
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data.getWeight(), data.getCity());
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}
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public void objectToKey(Object object, TupleOutput output)
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{
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Part part = (Part) object;
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<strong class="userinput"><code> output.writeString(part.getNumber());</code></strong>
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}
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public Object objectToData(Object object)
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{
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Part part = (Part) object;
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return new PartData(part.getName(), part.getColor(),
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part.getWeight(), part.getCity());
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}
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}
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...
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private static class SupplierBinding extends <strong class="userinput"><code>TupleSerialBinding</code></strong>
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{
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private SupplierBinding(ClassCatalog classCatalog, <strong class="userinput"><code>Class dataClass</code></strong>)
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{
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super(classCatalog, dataClass);
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}
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public Object entryToObject(<strong class="userinput"><code>TupleInput</code></strong> keyInput, Object dataInput)
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{
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<strong class="userinput"><code> String number = keyInput.readString();</code></strong>
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SupplierData data = (SupplierData) dataInput;
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return new Supplier(<strong class="userinput"><code>number</code></strong>, data.getName(),
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data.getStatus(), data.getCity());
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}
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public void objectToKey(Object object, TupleOutput output)
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{
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Supplier supplier = (Supplier) object;
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<strong class="userinput"><code> output.writeString(supplier.getNumber());</code></strong>
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}
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public Object objectToData(Object object)
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{
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Supplier supplier = (Supplier) object;
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return new SupplierData(supplier.getName(),
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supplier.getStatus(),
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supplier.getCity());
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}
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}
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...
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private static class ShipmentBinding extends <strong class="userinput"><code>TupleSerialBinding</code></strong>
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{
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private ShipmentBinding(ClassCatalog classCatalog, <strong class="userinput"><code>Class dataClass</code></strong>)
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{
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super(classCatalog, dataClass);
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}
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public Object entryToObject(<strong class="userinput"><code>TupleInput</code></strong> keyInput, Object dataInput)
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{
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<strong class="userinput"><code> String partNumber = keyInput.readString();
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String supplierNumber = keyInput.readString();</code></strong>
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ShipmentData data = (ShipmentData) dataInput;
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return new Shipment(<strong class="userinput"><code>partNumber, supplierNumber</code></strong>,
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data.getQuantity());
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}
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public void objectToKey(Object object, TupleOutput output)
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{
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Shipment shipment = (Shipment) object;
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<strong class="userinput"><code> output.writeString(shipment.getPartNumber());
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output.writeString(shipment.getSupplierNumber());</code></strong>
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}
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public Object objectToData(Object object)
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{
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Shipment shipment = (Shipment) object;
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return new ShipmentData(shipment.getQuantity());
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}
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}
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...
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} </pre>
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</div>
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<div class="navfooter">
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<hr />
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<table width="100%" summary="Navigation footer">
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<tr>
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<td width="40%" align="left"><a accesskey="p" href="tuplekeybindings.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="Tuple.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="sortedcollections.html">Next</a></td>
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</tr>
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<tr>
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<td width="40%" align="left" valign="top">
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Creating Tuple Key Bindings
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</td>
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<td width="20%" align="center">
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<a accesskey="h" href="index.html">Home</a>
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</td>
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<td width="40%" align="right" valign="top">
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Using Sorted Collections
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</td>
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</tr>
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</table>
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</div>
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</body>
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</html>
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