/*- * See the file LICENSE for redistribution information. * * Copyright (c) 2000,2008 Oracle. All rights reserved. * * $Id: SortedDoubleBinding.java,v 12.6 2008/02/07 17:12:25 mark Exp $ */ package com.sleepycat.bind.tuple; import com.sleepycat.db.DatabaseEntry; /** * A concrete <code>TupleBinding</code> for a <code>Double</code> primitive * wrapper or a <code>double</code> primitive. * * <p>This class produces byte array values that by default (without a custom * comparator) sort correctly, including sorting of negative values. * Therefore, this class should normally be used instead of {@link * DoubleBinding} which does not by default support sorting of negative values. * Please note that:</p> * <ul> * <li>The byte array (stored) formats used by {@link DoubleBinding} and * {@link SortedDoubleBinding} are different and incompatible. They are not * interchangeable once data has been stored.</li> * <li>An instance of {@link DoubleBinding}, not {@link SortedDoubleBinding}, * is returned by {@link TupleBinding#getPrimitiveBinding} method. Therefore, * to use {@link SortedDoubleBinding}, {@link TupleBinding#getPrimitiveBinding} * should not be called.</li> * </ul> * * <p>There are two ways to use this class:</p> * <ol> * <li>When using the {@link com.sleepycat.db} package directly, the static * methods in this class can be used to convert between primitive values and * {@link DatabaseEntry} objects.</li> * <li>When using the {@link com.sleepycat.collections} package, an instance of * this class can be used with any stored collection.</li> * </ol> */ public class SortedDoubleBinding extends TupleBinding { /* javadoc is inherited */ public Object entryToObject(TupleInput input) { return new Double(input.readSortedDouble()); } /* javadoc is inherited */ public void objectToEntry(Object object, TupleOutput output) { output.writeSortedDouble(((Number) object).doubleValue()); } /* javadoc is inherited */ protected TupleOutput getTupleOutput(Object object) { return DoubleBinding.sizedOutput(); } /** * Converts an entry buffer into a simple <code>double</code> value. * * @param entry is the source entry buffer. * * @return the resulting value. */ public static double entryToDouble(DatabaseEntry entry) { return entryToInput(entry).readSortedDouble(); } /** * Converts a simple <code>double</code> value into an entry buffer. * * @param val is the source value. * * @param entry is the destination entry buffer. */ public static void doubleToEntry(double val, DatabaseEntry entry) { outputToEntry(DoubleBinding.sizedOutput().writeSortedDouble(val), entry); } }