blob: f8f1a0befb15d45e222da701cf830e554d810f3a (
plain)
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
|
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.io;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
/**
* An {@link InputStream} that concatenates multiple substreams. At most
* one stream will be open at a time.
*
* @author Chris Nokleberg
* @since 1.0
*/
final class MultiInputStream extends InputStream {
private Iterator<? extends InputSupplier<? extends InputStream>> it;
private InputStream in;
/**
* Creates a new instance.
*
* @param it an iterator of I/O suppliers that will provide each substream
*/
public MultiInputStream(
Iterator<? extends InputSupplier<? extends InputStream>> it)
throws IOException {
this.it = it;
advance();
}
@Override public void close() throws IOException {
if (in != null) {
try {
in.close();
} finally {
in = null;
}
}
}
/**
* Closes the current input stream and opens the next one, if any.
*/
private void advance() throws IOException {
close();
if (it.hasNext()) {
in = it.next().getInput();
}
}
@Override public int available() throws IOException {
if (in == null) {
return 0;
}
return in.available();
}
@Override public boolean markSupported() {
return false;
}
@Override public int read() throws IOException {
if (in == null) {
return -1;
}
int result = in.read();
if (result == -1) {
advance();
return read();
}
return result;
}
@Override public int read(byte[] b, int off, int len) throws IOException {
if (in == null) {
return -1;
}
int result = in.read(b, off, len);
if (result == -1) {
advance();
return read(b, off, len);
}
return result;
}
@Override public long skip(long n) throws IOException {
if (in == null || n <= 0) {
return 0;
}
long result = in.skip(n);
if (result != 0) {
return result;
}
if (read() == -1) {
return 0;
}
return 1 + in.skip(n - 1);
}
}
|
