%line | %branch | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
org.apache.commons.net.io.FromNetASCIIInputStream |
|
|
1 | /* |
|
2 | * Copyright 2001-2005 The Apache Software Foundation |
|
3 | * |
|
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
|
5 | * you may not use this file except in compliance with the License. |
|
6 | * You may obtain a copy of the License at |
|
7 | * |
|
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
|
9 | * |
|
10 | * Unless required by applicable law or agreed to in writing, software |
|
11 | * distributed under the License is distributed on an "AS IS" BASIS, |
|
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
13 | * See the License for the specific language governing permissions and |
|
14 | * limitations under the License. |
|
15 | */ |
|
16 | package org.apache.commons.net.io; |
|
17 | ||
18 | import java.io.IOException; |
|
19 | import java.io.InputStream; |
|
20 | import java.io.PushbackInputStream; |
|
21 | ||
22 | /*** |
|
23 | * This class wraps an input stream, replacing all occurrences |
|
24 | * of <CR><LF> (carriage return followed by a linefeed), |
|
25 | * which is the NETASCII standard for representing a newline, with the |
|
26 | * local line separator representation. You would use this class to |
|
27 | * implement ASCII file transfers requiring conversion from NETASCII. |
|
28 | * <p> |
|
29 | * <p> |
|
30 | * @author Daniel F. Savarese |
|
31 | ***/ |
|
32 | ||
33 | public final class FromNetASCIIInputStream extends PushbackInputStream |
|
34 | { |
|
35 | static final boolean _noConversionRequired; |
|
36 | static final String _lineSeparator; |
|
37 | static final byte[] _lineSeparatorBytes; |
|
38 | ||
39 | static { |
|
40 | 1 | _lineSeparator = System.getProperty("line.separator"); |
41 | 1 | _noConversionRequired = _lineSeparator.equals("\r\n"); |
42 | 1 | _lineSeparatorBytes = _lineSeparator.getBytes(); |
43 | 1 | } |
44 | ||
45 | 32 | private int __length = 0; |
46 | ||
47 | /*** |
|
48 | * Returns true if the NetASCII line separator differs from the system |
|
49 | * line separator, false if they are the same. This method is useful |
|
50 | * to determine whether or not you need to instantiate a |
|
51 | * FromNetASCIIInputStream object. |
|
52 | * <p> |
|
53 | * @return True if the NETASCII line separator differs from the local |
|
54 | * system line separator, false if they are the same. |
|
55 | ***/ |
|
56 | public static final boolean isConversionRequired() |
|
57 | { |
|
58 | 32 | return !_noConversionRequired; |
59 | } |
|
60 | ||
61 | /*** |
|
62 | * Creates a FromNetASCIIInputStream instance that wraps an existing |
|
63 | * InputStream. |
|
64 | ***/ |
|
65 | public FromNetASCIIInputStream(InputStream input) |
|
66 | { |
|
67 | 32 | super(input, _lineSeparatorBytes.length + 1); |
68 | 32 | } |
69 | ||
70 | ||
71 | private int __read() throws IOException |
|
72 | { |
|
73 | int ch; |
|
74 | ||
75 | 127 | ch = super.read(); |
76 | ||
77 | 103 | if (ch == '\r') |
78 | { |
|
79 | 0 | ch = super.read(); |
80 | 0 | if (ch == '\n') |
81 | { |
|
82 | 0 | unread(_lineSeparatorBytes); |
83 | 0 | ch = super.read(); |
84 | // This is a kluge for read(byte[], ...) to read the right amount |
|
85 | 0 | --__length; |
86 | } |
|
87 | else |
|
88 | { |
|
89 | 0 | if (ch != -1) |
90 | 0 | unread(ch); |
91 | 0 | return '\r'; |
92 | } |
|
93 | } |
|
94 | ||
95 | 103 | return ch; |
96 | } |
|
97 | ||
98 | ||
99 | /*** |
|
100 | * Reads and returns the next byte in the stream. If the end of the |
|
101 | * message has been reached, returns -1. Note that a call to this method |
|
102 | * may result in multiple reads from the underlying input stream in order |
|
103 | * to convert NETASCII line separators to the local line separator format. |
|
104 | * This is transparent to the programmer and is only mentioned for |
|
105 | * completeness. |
|
106 | * <p> |
|
107 | * @return The next character in the stream. Returns -1 if the end of the |
|
108 | * stream has been reached. |
|
109 | * @exception IOException If an error occurs while reading the underlying |
|
110 | * stream. |
|
111 | ***/ |
|
112 | public int read() throws IOException |
|
113 | { |
|
114 | 0 | if (_noConversionRequired) |
115 | 0 | return super.read(); |
116 | ||
117 | 0 | return __read(); |
118 | } |
|
119 | ||
120 | ||
121 | /*** |
|
122 | * Reads the next number of bytes from the stream into an array and |
|
123 | * returns the number of bytes read. Returns -1 if the end of the |
|
124 | * stream has been reached. |
|
125 | * <p> |
|
126 | * @param buffer The byte array in which to store the data. |
|
127 | * @return The number of bytes read. Returns -1 if the |
|
128 | * end of the message has been reached. |
|
129 | * @exception IOException If an error occurs in reading the underlying |
|
130 | * stream. |
|
131 | ***/ |
|
132 | public int read(byte buffer[]) throws IOException |
|
133 | { |
|
134 | 0 | return read(buffer, 0, buffer.length); |
135 | } |
|
136 | ||
137 | ||
138 | /*** |
|
139 | * Reads the next number of bytes from the stream into an array and returns |
|
140 | * the number of bytes read. Returns -1 if the end of the |
|
141 | * message has been reached. The characters are stored in the array |
|
142 | * starting from the given offset and up to the length specified. |
|
143 | * <p> |
|
144 | * @param buffer The byte array in which to store the data. |
|
145 | * @param offset The offset into the array at which to start storing data. |
|
146 | * @param length The number of bytes to read. |
|
147 | * @return The number of bytes read. Returns -1 if the |
|
148 | * end of the stream has been reached. |
|
149 | * @exception IOException If an error occurs while reading the underlying |
|
150 | * stream. |
|
151 | ***/ |
|
152 | public int read(byte buffer[], class="keyword">int offset, class="keyword">int length) throws IOException |
|
153 | { |
|
154 | int ch, off; |
|
155 | ||
156 | 53 | if (length < 1) |
157 | 0 | return 0; |
158 | ||
159 | 53 | ch = available(); |
160 | ||
161 | 53 | __length = (length > ch ? ch : length); |
162 | ||
163 | // If nothing is available, block to read only one character |
|
164 | 53 | if (__length < 1) |
165 | 38 | __length = 1; |
166 | ||
167 | 53 | if (_noConversionRequired) |
168 | 0 | return super.read(buffer, offset, __length); |
169 | ||
170 | 53 | if ((ch = __read()) == -1) |
171 | 0 | return -1; |
172 | ||
173 | 29 | off = offset; |
174 | ||
175 | do |
|
176 | { |
|
177 | 103 | buffer[offset++] = (byte)ch; |
178 | } |
|
179 | 103 | while (--__length > 0 && (ch = __read()) != -1); |
180 | ||
181 | ||
182 | 29 | return (offset - off); |
183 | } |
|
184 | ||
185 | ||
186 | // PushbackInputStream in JDK 1.1.3 returns the wrong thing |
|
187 | /*** |
|
188 | * Returns the number of bytes that can be read without blocking EXCEPT |
|
189 | * when newline conversions have to be made somewhere within the |
|
190 | * available block of bytes. In other words, you really should not |
|
191 | * rely on the value returned by this method if you are trying to avoid |
|
192 | * blocking. |
|
193 | ***/ |
|
194 | public int available() throws IOException |
|
195 | { |
|
196 | 54 | return (buf.length - pos) + in.available(); |
197 | } |
|
198 | ||
199 | } |
This report is generated by jcoverage, Maven and Maven JCoverage Plugin. |