Mercurial > jdk8-mips64-public > jaxp / file comparison

comparison: src/com/sun/org/apache/regexp/internal/ReaderCharacterIterator.java

src/com/sun/org/apache/regexp/internal/ReaderCharacterIterator.java

changeset 2116
aaee9ae4799a
parent 759
7ea027fae4d8
equal deleted inserted replaced
2090:3b8ebb957957 2116:aaee9ae4799a
1 /*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5 /*
6 * Copyright 1999-2004 The Apache Software Foundation.
7 *
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20
21 package com.sun.org.apache.regexp.internal;
22
23 import java.io.Reader;
24 import java.io.IOException;
25
26 /**
27 * Encapsulates java.io.Reader as CharacterIterator
28 *
29 * @author <a href="mailto:ales.novak@netbeans.com">Ales Novak</a>
30 */
31 public final class ReaderCharacterIterator implements CharacterIterator
32 {
33 /** Underlying reader */
34 private final Reader reader;
35
36 /** Buffer of read chars */
37 private final StringBuffer buff;
38
39 /** read end? */
40 private boolean closed;
41
42 /** @param reader a Reader, which is parsed */
43 public ReaderCharacterIterator(Reader reader)
44 {
45 this.reader = reader;
46 this.buff = new StringBuffer(512);
47 this.closed = false;
48 }
49
50 /** @return a substring */
51 public String substring(int beginIndex, int endIndex)
52 {
53 try
54 {
55 ensure(endIndex);
56 return buff.toString().substring(beginIndex, endIndex);
57 }
58 catch (IOException e)
59 {
60 throw new StringIndexOutOfBoundsException(e.getMessage());
61 }
62 }
63
64 /** @return a substring */
65 public String substring(int beginIndex)
66 {
67 try
68 {
69 readAll();
70 return buff.toString().substring(beginIndex);
71 }
72 catch (IOException e)
73 {
74 throw new StringIndexOutOfBoundsException(e.getMessage());
75 }
76 }
77
78 /** @return a character at the specified position. */
79 public char charAt(int pos)
80 {
81 try
82 {
83 ensure(pos);
84 return buff.charAt(pos);
85 }
86 catch (IOException e)
87 {
88 throw new StringIndexOutOfBoundsException(e.getMessage());
89 }
90 }
91
92 /** @return <tt>true</tt> iff if the specified index is after the end of the character stream */
93 public boolean isEnd(int pos)
94 {
95 if (buff.length() > pos)
96 {
97 return false;
98 }
99 else
100 {
101 try
102 {
103 ensure(pos);
104 return (buff.length() <= pos);
105 }
106 catch (IOException e)
107 {
108 throw new StringIndexOutOfBoundsException(e.getMessage());
109 }
110 }
111 }
112
113 /** Reads n characters from the stream and appends them to the buffer */
114 private int read(int n) throws IOException
115 {
116 if (closed)
117 {
118 return 0;
119 }
120
121 char[] c = new char[n];
122 int count = 0;
123 int read = 0;
124
125 do
126 {
127 read = reader.read(c);
128 if (read < 0) // EOF
129 {
130 closed = true;
131 break;
132 }
133 count += read;
134 buff.append(c, 0, read);
135 }
136 while (count < n);
137
138 return count;
139 }
140
141 /** Reads rest of the stream. */
142 private void readAll() throws IOException
143 {
144 while(! closed)
145 {
146 read(1000);
147 }
148 }
149
150 /** Reads chars up to the idx */
151 private void ensure(int idx) throws IOException
152 {
153 if (closed)
154 {
155 return;
156 }
157
158 if (idx < buff.length())
159 {
160 return;
161 }
162 read(idx + 1 - buff.length());
163 }
164 }

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