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comparison app/src/main/java/org/tn5250j/framework/tn5250/Stream5250.java @ 438:d29cce60f393

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migrate from Eclipse to Android Studio
author Carl Byington <carl@five-ten-sg.com>
date Thu, 03 Dec 2015 11:23:55 -0800
parents src/org/tn5250j/framework/tn5250/Stream5250.java@77ac18bc1b2f
children 8fa8e73e2f5c
comparison
equal deleted inserted replaced
437:208b31032318 438:d29cce60f393
1 /**
2 * Title: tn5250J
3 * Copyright: Copyright (c) 2001
4 * Company:
5 * @author Kenneth J. Pouncey
6 * @version 0.4
7 *
8 * Description:
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
13 * any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this software; see the file COPYING. If not, write to
22 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
23 * Boston, MA 02111-1307 USA
24 *
25 */
26 package org.tn5250j.framework.tn5250;
27
28 public class Stream5250 {
29
30 public int streamSize;
31 public int opCode;
32 public int dataStart;
33 public int pos;
34 public byte buffer[];
35
36 public Stream5250(byte abyte0[]) {
37 buffer = abyte0;
38 // size without end of record 0xFF 0xEF
39 streamSize = (abyte0[0] & 0xff) << 8 | abyte0[1] & 0xff;
40 opCode = abyte0[9];
41 dataStart = 6 + abyte0[6];
42 pos = dataStart;
43 }
44
45 public Stream5250() {
46 buffer = null;
47 streamSize = 0;
48 opCode = 0;
49 dataStart = 0;
50 pos = dataStart;
51 }
52
53 /**
54 * This method takes a byte array and initializes the object information
55 * to be used.
56 *
57 * @param abyte0
58 */
59 public void initialize(byte abyte0[]) {
60 buffer = abyte0;
61 // size without end of record 0xFF 0xEF
62 streamSize = (abyte0[0] & 0xff) << 8 | abyte0[1] & 0xff;
63 opCode = abyte0[9];
64 dataStart = 6 + abyte0[6];
65 pos = dataStart;
66 }
67
68 public final int getOpCode() {
69 return opCode;
70 }
71
72 public final byte getNextByte()
73 throws Exception {
74 if (buffer == null || pos > buffer.length)
75 throw new Exception("Buffer length exceeded: " + pos);
76 else
77 return buffer[pos++];
78 }
79
80 public final void setPrevByte()
81 throws Exception {
82 if (pos == 0) {
83 throw new Exception("Index equals zero.");
84 }
85 else {
86 pos--;
87 return;
88 }
89 }
90
91 /**
92 * Returns where we are in the buffer
93 * @return position in the buffer
94 */
95 public final int getCurrentPos() {
96 return pos;
97 }
98
99 public final byte getByteOffset(int off)
100 throws Exception {
101 if (buffer == null || (pos + off) > buffer.length)
102 throw new Exception("Buffer length exceeded: " + pos);
103 else
104 return buffer[pos + off];
105 }
106
107 public final boolean size() {
108 return pos >= streamSize;
109 }
110
111
112 /**
113 * Determines if any more bytes are available in the buffer to be processed.
114 * @return yes or no
115 */
116 public final boolean hasNext() {
117 // return pos >= buffer.length;
118 return pos < streamSize;
119 }
120
121 /**
122 * This routine will retrieve a segment based on the first two bytes being
123 * the length of the segment.
124 *
125 * @return a new byte array containing the bytes of the segment.
126 * @throws Exception
127 */
128 public final byte[] getSegment() throws Exception {
129 // The first two bytes contain the length of the segment.
130 int length = ((buffer[pos] & 0xff) << 8 | (buffer[pos + 1] & 0xff));
131 // allocate space for it.
132 byte[] segment = new byte[length];
133 getSegment(segment, length, true);
134 return segment;
135 }
136
137
138 /**
139 * This routine will retrieve a byte array based on the first two bytes being
140 * the length of the segment.
141 *
142 * @param segment - byte array
143 * @param length - length of segment to return
144 * @param adjustPos - adjust the position of the buffer to the end of the seg
145 * ment
146 * @throws Exception
147 */
148 public final void getSegment(byte[] segment, int length, boolean adjustPos)
149 throws Exception {
150 // If the length is larger than what is available throw an exception
151 if ((pos + length) > buffer.length)
152 throw new Exception("Buffer length exceeded: start " + pos
153 + " length " + length);
154
155 // use the system array copy to move the bytes from the buffer
156 // to the allocated byte array
157 System.arraycopy(buffer, pos, segment, 0, length);
158
159 // update the offset to be after the segment so the next byte can be read
160 if (adjustPos)
161 pos += length;
162 }
163
164 }