blob: 154f83e17aa8e56704cfa6254ac87b3c4308eb24 (
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
|
// Copyright 2016 The Bazel Authors. All rights reserved.
//
// 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.devtools.build.android;
import java.io.IOException;
import java.lang.reflect.Field;
import java.net.URL;
import java.net.URLClassLoader;
import java.nio.file.Path;
import java.util.HashMap;
import java.util.Map;
/**
* Loads android.R.attr resource IDs from an android jar. An alternative may be to parse the
* res/values/public.xml from the SDK, but the class loading approach is ~20ms, right now.
*/
public class AndroidFrameworkAttrIdJar implements AndroidFrameworkAttrIdProvider {
private static final String ANDROID_ATTR_CLASS = "android.R$attr";
private final Path androidJar;
private Map<String, Integer> cachedFields;
public AndroidFrameworkAttrIdJar(Path androidJar) {
this.androidJar = androidJar;
}
@Override
public int getAttrId(String fieldName) throws AttrLookupException {
// Lazily load the ANDROID_ATTR_CLASS from the androidJar, to save time if never end up
// needing the android framework attributes. This provider can only work for one given
// androidJar path, since we never invalidate the lazily filled cache.
if (cachedFields == null) {
cachedFields = getAttrFields();
}
Integer result = cachedFields.get(fieldName);
if (result == null) {
throw new AttrLookupException("Android attribute not found: " + fieldName);
}
return result;
}
private Map<String, Integer> getAttrFields() throws AttrLookupException {
try (URLClassLoader urlClassLoader =
new URLClassLoader(new URL[] {androidJar.toUri().toURL()})) {
Class<?> attrClass = urlClassLoader.loadClass(ANDROID_ATTR_CLASS);
Map<String, Integer> attributeIds = new HashMap<>();
for (Field field : attrClass.getFields()) {
attributeIds.put(field.getName(), field.getInt(null));
}
return attributeIds;
} catch (IOException | ClassNotFoundException | IllegalAccessException e) {
throw new AttrLookupException(e);
}
}
}
|
