1 //
2 // ========================================================================
3 // Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.server;
20
21 import java.io.IOException;
22
23 /** OutputWriter.
24 * A writer that can wrap a {@link HttpOutput} stream and provide
25 * character encodings.
26 *
27 * The UTF-8 encoding is done by this class and no additional
28 * buffers or Writers are used.
29 * The UTF-8 code was inspired by http://javolution.org
30 */
31 public class Utf8HttpWriter extends HttpWriter
32 {
33 int _surrogate=0;
34
35 /* ------------------------------------------------------------ */
36 public Utf8HttpWriter(HttpOutput out)
37 {
38 super(out);
39 }
40
41 /* ------------------------------------------------------------ */
42 @Override
43 public void write (char[] s,int offset, int length) throws IOException
44 {
45 HttpOutput out = _out;
46 if (length==0)
47 out.closeIfAllContentWritten();
48
49 while (length > 0)
50 {
51 _bytes.reset();
52 int chars = length>MAX_OUTPUT_CHARS?MAX_OUTPUT_CHARS:length;
53
54 byte[] buffer=_bytes.getBuf();
55 int bytes=_bytes.getCount();
56
57 if (bytes+chars>buffer.length)
58 chars=buffer.length-bytes;
59
60 for (int i = 0; i < chars; i++)
61 {
62 int code = s[offset+i];
63
64 // Do we already have a surrogate?
65 if(_surrogate==0)
66 {
67 // No - is this char code a surrogate?
68 if(Character.isHighSurrogate((char)code))
69 {
70 _surrogate=code; // UCS-?
71 continue;
72 }
73 }
74 // else handle a low surrogate
75 else if(Character.isLowSurrogate((char)code))
76 {
77 code = Character.toCodePoint((char)_surrogate, (char)code); // UCS-4
78 }
79 // else UCS-2
80 else
81 {
82 code=_surrogate; // UCS-2
83 _surrogate=0; // USED
84 i--;
85 }
86
87 if ((code & 0xffffff80) == 0)
88 {
89 // 1b
90 if (bytes>=buffer.length)
91 {
92 chars=i;
93 break;
94 }
95 buffer[bytes++]=(byte)(code);
96 }
97 else
98 {
99 if((code&0xfffff800)==0)
100 {
101 // 2b
102 if (bytes+2>buffer.length)
103 {
104 chars=i;
105 break;
106 }
107 buffer[bytes++]=(byte)(0xc0|(code>>6));
108 buffer[bytes++]=(byte)(0x80|(code&0x3f));
109 }
110 else if((code&0xffff0000)==0)
111 {
112 // 3b
113 if (bytes+3>buffer.length)
114 {
115 chars=i;
116 break;
117 }
118 buffer[bytes++]=(byte)(0xe0|(code>>12));
119 buffer[bytes++]=(byte)(0x80|((code>>6)&0x3f));
120 buffer[bytes++]=(byte)(0x80|(code&0x3f));
121 }
122 else if((code&0xff200000)==0)
123 {
124 // 4b
125 if (bytes+4>buffer.length)
126 {
127 chars=i;
128 break;
129 }
130 buffer[bytes++]=(byte)(0xf0|(code>>18));
131 buffer[bytes++]=(byte)(0x80|((code>>12)&0x3f));
132 buffer[bytes++]=(byte)(0x80|((code>>6)&0x3f));
133 buffer[bytes++]=(byte)(0x80|(code&0x3f));
134 }
135 else if((code&0xf4000000)==0)
136 {
137 // 5b
138 if (bytes+5>buffer.length)
139 {
140 chars=i;
141 break;
142 }
143 buffer[bytes++]=(byte)(0xf8|(code>>24));
144 buffer[bytes++]=(byte)(0x80|((code>>18)&0x3f));
145 buffer[bytes++]=(byte)(0x80|((code>>12)&0x3f));
146 buffer[bytes++]=(byte)(0x80|((code>>6)&0x3f));
147 buffer[bytes++]=(byte)(0x80|(code&0x3f));
148 }
149 else if((code&0x80000000)==0)
150 {
151 // 6b
152 if (bytes+6>buffer.length)
153 {
154 chars=i;
155 break;
156 }
157 buffer[bytes++]=(byte)(0xfc|(code>>30));
158 buffer[bytes++]=(byte)(0x80|((code>>24)&0x3f));
159 buffer[bytes++]=(byte)(0x80|((code>>18)&0x3f));
160 buffer[bytes++]=(byte)(0x80|((code>>12)&0x3f));
161 buffer[bytes++]=(byte)(0x80|((code>>6)&0x3f));
162 buffer[bytes++]=(byte)(0x80|(code&0x3f));
163 }
164 else
165 {
166 buffer[bytes++]=(byte)('?');
167 }
168
169 _surrogate=0; // USED
170
171 if (bytes==buffer.length)
172 {
173 chars=i+1;
174 break;
175 }
176 }
177 }
178 _bytes.setCount(bytes);
179
180 _bytes.writeTo(out);
181 length-=chars;
182 offset+=chars;
183 }
184 }
185 }