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
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.tools.ant.types.resources;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.types.ResourceCollection;
import org.apache.tools.ant.util.FileUtils;
/**
* A resource that transforms the content of another resource.
*
* <p>Wraps around another resource, delegates all queries (except
* getSize) to that other resource but transforms stream content
* on the fly.</p>
*
* @since Ant 1.8
*/
public abstract class ContentTransformingResource extends ResourceDecorator {
private static final int BUFFER_SIZE = 8192;
/** no arg constructor */
protected ContentTransformingResource() {
}
/**
* Constructor with another resource to wrap.
* @param other the resource to wrap.
*/
protected ContentTransformingResource(final ResourceCollection other) {
super(other);
}
/**
* Get the size of this Resource.
* @return the size, as a long, 0 if the Resource does not exist (for
* compatibility with java.io.File), or UNKNOWN_SIZE if not known.
*/
@Override
public long getSize() {
if (isExists()) {
InputStream in = null;
try {
in = getInputStream();
final byte[] buf = new byte[BUFFER_SIZE];
int size = 0;
int readNow;
while ((readNow = in.read(buf, 0, buf.length)) > 0) {
size += readNow;
}
return size;
} catch (final IOException ex) {
throw new BuildException("caught exception while reading "
+ getName(), ex);
} finally {
FileUtils.close(in);
}
} else {
return 0;
}
}
/**
* Get an InputStream for the Resource.
* @return an InputStream containing this Resource's content.
* @throws IOException if unable to provide the content of this
* Resource as a stream.
* @throws UnsupportedOperationException if InputStreams are not
* supported for this Resource type.
*/
@Override
public InputStream getInputStream() throws IOException {
InputStream in = getResource().getInputStream();
if (in != null) {
in = wrapStream(in);
}
return in;
}
/**
* Get an OutputStream for the Resource.
* @return an OutputStream to which content can be written.
* @throws IOException if unable to provide the content of this
* Resource as a stream.
* @throws UnsupportedOperationException if OutputStreams are not
* supported for this Resource type.
*/
@Override
public OutputStream getOutputStream() throws IOException {
OutputStream out = getResource().getOutputStream();
if (out != null) {
out = wrapStream(out);
}
return out;
}
/**
* Suppress FileProvider, re-implement Appendable
*/
@Override
public <T> T as(final Class<T> clazz) {
if (Appendable.class.isAssignableFrom(clazz)) {
if (isAppendSupported()) {
final Appendable a =
getResource().as(Appendable.class);
if (a != null) {
return clazz.cast(new Appendable() {
public OutputStream getAppendOutputStream()
throws IOException {
OutputStream out = a.getAppendOutputStream();
if (out != null) {
out = wrapStream(out);
}
return out;
}
});
}
}
return null;
}
return FileProvider.class.isAssignableFrom(clazz)
? null : getResource().as(clazz);
}
/**
* Learn whether the transformation performed allows appends.
*
* <p>In general compressed outputs will become invalid if they
* are appended to, for example.</p>
*
* <p>This implementations returns false.</p>
*/
protected boolean isAppendSupported() {
return false;
}
/**
* Get a content-filtering/transforming InputStream.
*
* @param in InputStream to wrap, will never be null.
* @return a compressed inputstream.
* @throws IOException if there is a problem.
*/
protected abstract InputStream wrapStream(InputStream in)
throws IOException;
/**
* Get a content-filtering/transforming OutputStream.
*
* @param out OutputStream to wrap, will never be null.
* @return a compressed outputstream.
* @throws IOException if there is a problem.
*/
protected abstract OutputStream wrapStream(OutputStream out)
throws IOException;
}
|
