| 1 | /* |
| 2 | |
| 3 | Derby - Class com.ihost.cs.ReuseFactory |
| 4 | |
| 5 | Copyright 1999, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.util; |
| 22 | |
| 23 | /** |
| 24 | Factory methods for reusable objects. So far, the objects allocated |
| 25 | by this factory are all immutable. Any immutable object can be re-used. |
| 26 | |
| 27 | All the methods in this class are static. |
| 28 | */ |
| 29 | public class ReuseFactory { |
| 30 | |
| 31 | /** Private constructor so no instances can be made */ |
| 32 | private ReuseFactory() { |
| 33 | } |
| 34 | |
| 35 | private static final Integer[] staticInts = |
| 36 | {new Integer(0), new Integer(1), new Integer(2), new Integer(3), |
| 37 | new Integer(4), new Integer(5), new Integer(6), new Integer(7), |
| 38 | new Integer(8), new Integer(9), new Integer(10), new Integer(11), |
| 39 | new Integer(12), new Integer(13), new Integer(14), new Integer(15), |
| 40 | new Integer(16), new Integer(17), new Integer(18)}; |
| 41 | private static final Integer FIFTY_TWO = new Integer(52); |
| 42 | private static final Integer TWENTY_THREE = new Integer(23); |
| 43 | private static final Integer MAXINT = new Integer(Integer.MAX_VALUE); |
| 44 | private static final Integer MINUS_ONE = new Integer(-1); |
| 45 | |
| 46 | public static Integer getInteger(int i) |
| 47 | { |
| 48 | if (i >= 0 && i < staticInts.length) |
| 49 | { |
| 50 | return staticInts[i]; |
| 51 | } |
| 52 | else |
| 53 | { |
| 54 | // Look for other common values |
| 55 | switch (i) |
| 56 | { |
| 57 | case 23: |
| 58 | return TWENTY_THREE; // precision of Int |
| 59 | |
| 60 | case 52: |
| 61 | return FIFTY_TWO; // precision of Double |
| 62 | |
| 63 | case Integer.MAX_VALUE: |
| 64 | return MAXINT; |
| 65 | |
| 66 | case -1: |
| 67 | return MINUS_ONE; |
| 68 | |
| 69 | default: |
| 70 | return new Integer(i); |
| 71 | } |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | private static final Short[] staticShorts = |
| 76 | {new Short((short) 0), new Short((short) 1), new Short((short) 2), |
| 77 | new Short((short) 3), new Short((short) 4), new Short((short) 5), |
| 78 | new Short((short) 6), new Short((short) 7), new Short((short) 8), |
| 79 | new Short((short) 9), new Short((short) 10)}; |
| 80 | |
| 81 | public static Short getShort(short i) |
| 82 | { |
| 83 | if (i >= 0 && i < staticShorts.length) |
| 84 | return staticShorts[i]; |
| 85 | else |
| 86 | return new Short(i); |
| 87 | } |
| 88 | |
| 89 | private static final Byte[] staticBytes = |
| 90 | {new Byte((byte) 0), new Byte((byte) 1), new Byte((byte) 2), |
| 91 | new Byte((byte) 3), new Byte((byte) 4), new Byte((byte) 5), |
| 92 | new Byte((byte) 6), new Byte((byte) 7), new Byte((byte) 8), |
| 93 | new Byte((byte) 9), new Byte((byte) 10)}; |
| 94 | |
| 95 | public static Byte getByte(byte i) |
| 96 | { |
| 97 | if (i >= 0 && i < staticBytes.length) |
| 98 | return staticBytes[i]; |
| 99 | else |
| 100 | return new Byte(i); |
| 101 | } |
| 102 | |
| 103 | private static final Long[] staticLongs = |
| 104 | {new Long(0), new Long(1), new Long(2), |
| 105 | new Long(3), new Long(4), new Long(5), |
| 106 | new Long(6), new Long(7), new Long(8), |
| 107 | new Long(9), new Long(10)}; |
| 108 | |
| 109 | public static Long getLong(long i) |
| 110 | { |
| 111 | if (i >= 0 && i < staticLongs.length) |
| 112 | return staticLongs[(int) i]; |
| 113 | else |
| 114 | return new Long(i); |
| 115 | } |
| 116 | |
| 117 | private static final Boolean staticFalse = new Boolean( false); |
| 118 | private static final Boolean staticTrue = new Boolean( true); |
| 119 | |
| 120 | public static Boolean getBoolean( boolean b) |
| 121 | { |
| 122 | return b ? staticTrue : staticFalse; |
| 123 | } |
| 124 | } |