1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
/*
========== licence begin GPL
Copyright (C) 2002-2003 SAP AG
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
========== licence end
*/
package com.sap.dbtech.util;
import java.io.*;
/**
*
*/
public class JoinStream
extends InputStream
{
protected InputStream [] instreams;
protected InputStream currentStream;
protected int currentIndex = -1;
/**
* creates a new JoinStream
*/
public
JoinStream (
InputStream [] instreams)
{
this.instreams = instreams;
this.nextStream ();
}
/**
*
*/
protected void
nextStream ()
{
++this.currentIndex;
if (this.currentIndex >= this.instreams.length) {
this.currentStream = null;
}
else {
this.currentStream = this.instreams [this.currentIndex];
}
}
/**
*
* @return int
* @param b byte[]
* @param off int
* @param len int
* @exception StreamIOException
*/
public int
read(
byte b[],
int off,
int len)
throws IOException
{
int result = 0;
int chunkLen;
while ((this.currentStream != null) && (len > 0)) {
chunkLen = this.currentStream.read (b, off, len);
if (chunkLen == -1) {
this.nextStream ();
}
else {
off += chunkLen;
len -= chunkLen;
result += chunkLen;
}
}
if ((result == 0) && (this.currentStream == null)) {
result = -1;
}
return result;
}
/**
* read method comment.
*/
public int
read()
throws IOException
{
int result = 0;
while (this.currentStream != null) {
result = this.currentStream.read ();
if (result == -1) {
this.nextStream ();
}
}
if (this.currentStream == null) {
result = -1;
}
return result;
}
/**
* Closes this input stream and releases any system resources associated
* with the stream.
*
* <p> The <code>close</code> method of <code>InputStream</code> does
* nothing.
*
* @exception IOException if an I/O error occurs.
*/
public void
close()
throws IOException
{
for (int i = this.currentIndex; i < this.instreams.length; ++i) {
try {
if (this.instreams [i] != null) {
this.instreams [i].close ();
}
}
catch (IOException exc) {
// ignore
}
}
}
/**
* Tests if this input stream supports the <code>mark</code> and
* <code>reset</code> methods. The <code>markSupported</code> method of
* <code>InputStream</code> returns <code>false</code>.
*
* @return <code>true</code> if this true type supports the mark and reset
* method; <code>false</code> otherwise.
* @see java.io.InputStream#mark(int)
* @see java.io.InputStream#reset()
*/
public boolean
markSupported()
{
return false;
}
}
|
