1 /*
2  * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4  *
5  * This code is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 only, as
7  * published by the Free Software Foundation.  Oracle designates this
8  * particular file as subject to the "Classpath" exception as provided
9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 
26 package jdk.internal.reflect;
27 
28 /** It is necessary to use a "bootstrap" UTF-8 encoder for encoding
29     constant pool entries because the character set converters rely on
30     Class.newInstance(). */
31 
32 class UTF8 {
33     // This encoder is not quite correct.  It does not handle surrogate pairs.
encode(String str)34     static byte[] encode(String str) {
35         int len = str.length();
36         byte[] res = new byte[utf8Length(str)];
37         int utf8Idx = 0;
38         try {
39             for (int i = 0; i < len; i++) {
40                 int c = str.charAt(i) & 0xFFFF;
41                 if (c >= 0x0001 && c <= 0x007F) {
42                     res[utf8Idx++] = (byte) c;
43                 } else if (c == 0x0000 ||
44                            (c >= 0x0080 && c <= 0x07FF)) {
45                     res[utf8Idx++] = (byte) (0xC0 + (c >> 6));
46                     res[utf8Idx++] = (byte) (0x80 + (c & 0x3F));
47                 } else {
48                     res[utf8Idx++] = (byte) (0xE0 + (c >> 12));
49                     res[utf8Idx++] = (byte) (0x80 + ((c >> 6) & 0x3F));
50                     res[utf8Idx++] = (byte) (0x80 + (c & 0x3F));
51                 }
52             }
53         } catch (ArrayIndexOutOfBoundsException e) {
54             throw new InternalError
55                 ("Bug in sun.reflect bootstrap UTF-8 encoder", e);
56         }
57         return res;
58     }
59 
utf8Length(String str)60     private static int utf8Length(String str) {
61         int len = str.length();
62         int utf8Len = 0;
63         for (int i = 0; i < len; i++) {
64             int c = str.charAt(i) & 0xFFFF;
65             if (c >= 0x0001 && c <= 0x007F) {
66                 utf8Len += 1;
67             } else if (c == 0x0000 ||
68                        (c >= 0x0080 && c <= 0x07FF)) {
69                 utf8Len += 2;
70             } else {
71                 utf8Len += 3;
72             }
73         }
74         return utf8Len;
75     }
76 }
77