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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