001:
002: /*
003: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
004: *
005: * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
006: *
007: * Portions Copyright Apache Software Foundation.
008: *
009: * The contents of this file are subject to the terms of either the GNU
010: * General Public License Version 2 only ("GPL") or the Common Development
011: * and Distribution License("CDDL") (collectively, the "License"). You
012: * may not use this file except in compliance with the License. You can obtain
013: * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
014: * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
015: * language governing permissions and limitations under the License.
016: *
017: * When distributing the software, include this License Header Notice in each
018: * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
019: * Sun designates this particular file as subject to the "Classpath" exception
020: * as provided by Sun in the GPL Version 2 section of the License file that
021: * accompanied this code. If applicable, add the following below the License
022: * Header, with the fields enclosed by brackets [] replaced by your own
023: * identifying information: "Portions Copyrighted [year]
024: * [name of copyright owner]"
025: *
026: * Contributor(s):
027: *
028: * If you wish your version of this file to be governed by only the CDDL or
029: * only the GPL Version 2, indicate your decision by adding "[Contributor]
030: * elects to include this software in this distribution under the [CDDL or GPL
031: * Version 2] license." If you don't indicate a single choice of license, a
032: * recipient has the option to distribute your version of this file under
033: * either the CDDL, the GPL Version 2 or to extend the choice of license to
034: * its licensees as provided above. However, if you add GPL Version 2 code
035: * and therefore, elected the GPL Version 2 license, then the option applies
036: * only if the new code is made subject to such option by the copyright
037: * holder.
038: */
039:
040: package javax.servlet;
041:
042: import java.io.InputStream;
043: import java.io.IOException;
044:
045: /**
046: *
047: * Provides an input stream for reading binary data from a client
048: * request, including an efficient <code>readLine</code> method
049: * for reading data one line at a time. With some protocols, such
050: * as HTTP POST and PUT, a <code>ServletInputStream</code>
051: * object can be used to read data sent from the client.
052: *
053: * <p>A <code>ServletInputStream</code> object is normally retrieved via
054: * the {@link ServletRequest#getInputStream} method.
055: *
056: *
057: * <p>This is an abstract class that a servlet container implements.
058: * Subclasses of this class
059: * must implement the <code>java.io.InputStream.read()</code> method.
060: *
061: *
062: * @author Various
063: *
064: * @see ServletRequest
065: *
066: */
067:
068: public abstract class ServletInputStream extends InputStream {
069:
070: /**
071: * Does nothing, because this is an abstract class.
072: *
073: */
074:
075: protected ServletInputStream() {
076: }
077:
078: /**
079: *
080: * Reads the input stream, one line at a time. Starting at an
081: * offset, reads bytes into an array, until it reads a certain number
082: * of bytes or reaches a newline character, which it reads into the
083: * array as well.
084: *
085: * <p>This method returns -1 if it reaches the end of the input
086: * stream before reading the maximum number of bytes.
087: *
088: *
089: *
090: * @param b an array of bytes into which data is read
091: *
092: * @param off an integer specifying the character at which
093: * this method begins reading
094: *
095: * @param len an integer specifying the maximum number of
096: * bytes to read
097: *
098: * @return an integer specifying the actual number of bytes
099: * read, or -1 if the end of the stream is reached
100: *
101: * @exception IOException if an input or output exception has occurred
102: *
103: */
104:
105: public int readLine(byte[] b, int off, int len) throws IOException {
106:
107: if (len <= 0) {
108: return 0;
109: }
110: int count = 0, c;
111:
112: while ((c = read()) != -1) {
113: b[off++] = (byte) c;
114: count++;
115: if (c == '\n' || count == len) {
116: break;
117: }
118: }
119: return count > 0 ? count : -1;
120: }
121: }
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