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Java > Open Source Codes > org > netbeans > lib > lexer > IntegerCache


1 /*
2  * The contents of this file are subject to the terms of the Common Development
3  * and Distribution License (the License). You may not use this file except in
4  * compliance with the License.
5  *
6  * You can obtain a copy of the License at http://www.netbeans.org/cddl.html
7  * or http://www.netbeans.org/cddl.txt.
8  *
9  * When distributing Covered Code, include this CDDL Header Notice in each file
10  * and include the License file at http://www.netbeans.org/cddl.txt.
11  * If applicable, add the following below the CDDL Header, with the fields
12  * enclosed by brackets [] replaced by your own identifying information:
13  * "Portions Copyrighted [year] [name of copyright owner]"
14  *
15  * The Original Software is NetBeans. The Initial Developer of the Original
16  * Software is Sun Microsystems, Inc. Portions Copyright 1997-2007 Sun
17  * Microsystems, Inc. All Rights Reserved.
18  */
19
20 package org.netbeans.lib.lexer;
21
22 /**
23  * Cache of java.lang.Integer instances.
24  *
25  * @author Miloslav Metelka
26  * @version 1.00
27  */
28
29 public final class IntegerCache {
30
31     // Should cache the same what Integer.valueOf(int) does on 1.5
32 private static final int MAX_CACHED_INTEGER = 127;
33
34     private static final Integer JavaDoc[] cache = new Integer JavaDoc[MAX_CACHED_INTEGER + 1];
35
36     public static Integer JavaDoc integer(int i) {
37         Integer JavaDoc integer;
38         if (i <= MAX_CACHED_INTEGER) {
39             integer = cache[i];
40             if (integer == null) {
41                 integer = Integer.valueOf(i); // possibly delegate to global cache
42 cache[i] = integer; // may lead to multiple instances but no problem with that
43 }
44
45         } else { // cannot cache
46 integer = new Integer JavaDoc(i);
47         }
48         return integer;
49     }
50     
51 }
52
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