1
2
3 /*
4 * The contents of this file are subject to the terms
5 * of the Common Development and Distribution License
6 * (the "License"). You may not use this file except
7 * in compliance with the License.
8 *
9 * You can obtain a copy of the license at
10 * glassfish/bootstrap/legal/CDDLv1.0.txt or
11 * https://glassfish.dev.java.net/public/CDDLv1.0.html.
12 * See the License for the specific language governing
13 * permissions and limitations under the License.
14 *
15 * When distributing Covered Code, include this CDDL
16 * HEADER in each file and include the License file at
17 * glassfish/bootstrap/legal/CDDLv1.0.txt. If applicable,
18 * add the following below this CDDL HEADER, with the
19 * fields enclosed by brackets "[]" replaced with your
20 * own identifying information: Portions Copyright [yyyy]
21 * [name of copyright owner]
22 *
23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
24 *
25 * Portions Copyright Apache Software Foundation.
26 */
27
28 package javax.servlet;
29
30 import java.io.InputStream;
31 import java.io.IOException;
32
33 /**
34 *
35 * Provides an input stream for reading binary data from a client
36 * request, including an efficient <code>readLine</code> method
37 * for reading data one line at a time. With some protocols, such
38 * as HTTP POST and PUT, a <code>ServletInputStream</code>
39 * object can be used to read data sent from the client.
40 *
41 * <p>A <code>ServletInputStream</code> object is normally retrieved via
42 * the {@link ServletRequest#getInputStream} method.
43 *
44 *
45 * <p>This is an abstract class that a servlet container implements.
46 * Subclasses of this class
47 * must implement the <code>java.io.InputStream.read()</code> method.
48 *
49 *
50 * @author Various
51 *
52 * @see ServletRequest
53 *
54 */
55
56 public abstract class ServletInputStream extends InputStream {
57
58
59
60 /**
61 * Does nothing, because this is an abstract class.
62 *
63 */
64
65 protected ServletInputStream() { }
66
67
68
69
70 /**
71 *
72 * Reads the input stream, one line at a time. Starting at an
73 * offset, reads bytes into an array, until it reads a certain number
74 * of bytes or reaches a newline character, which it reads into the
75 * array as well.
76 *
77 * <p>This method returns -1 if it reaches the end of the input
78 * stream before reading the maximum number of bytes.
79 *
80 *
81 *
82 * @param b an array of bytes into which data is read
83 *
84 * @param off an integer specifying the character at which
85 * this method begins reading
86 *
87 * @param len an integer specifying the maximum number of
88 * bytes to read
89 *
90 * @return an integer specifying the actual number of bytes
91 * read, or -1 if the end of the stream is reached
92 *
93 * @exception IOException if an input or output exception has occurred
94 *
95 */
96
97 public int readLine(byte[] b, int off, int len) throws IOException {
98
99 if (len <= 0) {
100 return 0;
101 }
102 int count = 0, c;
103
104 while ((c = read()) != -1) {
105 b[off++] = (byte)c;
106 count++;
107 if (c == '\n' || count == len) {
108 break;
109 }
110 }
111 return count > 0 ? count : -1;
112 }
113 }
114
115
116