1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.car.test.utils;
18 
19 import android.annotation.Nullable;
20 import android.os.SystemClock;
21 import java.io.File;
22 import java.io.IOException;
23 import java.nio.file.FileVisitResult;
24 import java.nio.file.Files;
25 import java.nio.file.Path;
26 import java.nio.file.SimpleFileVisitor;
27 import java.nio.file.attribute.BasicFileAttributes;
28 
29 /**
30  * A utility class that creates a temporary directory.
31  * The directory, and any files contained within, are automatically deleted when calling close().
32  *
33  * Example usage:
34  *
35  * try (TemporaryDirectory tf = new TemporaryDirectory("myTest")) {
36  *     ...
37  * } // directory gets deleted here
38  */
39 public class TemporaryDirectory implements AutoCloseable {
40     private Path mDirectory;
41 
42     private static final class DeletingVisitor extends SimpleFileVisitor<Path> {
consume(Path path)43         FileVisitResult consume(Path path) throws IOException {
44             Files.delete(path);
45             return FileVisitResult.CONTINUE;
46         }
47 
48         @Override
visitFile(Path path, BasicFileAttributes basicFileAttributes)49         public FileVisitResult visitFile(Path path, BasicFileAttributes basicFileAttributes)
50                 throws IOException {
51             return consume(path);
52         }
53 
54         @Override
postVisitDirectory(Path path, IOException e)55         public FileVisitResult postVisitDirectory(Path path, IOException e)
56                 throws IOException {
57             return consume(path);
58         }
59     }
60 
61     private static final SimpleFileVisitor<Path> DELETE = new DeletingVisitor();
62 
TemporaryDirectory(Path directory)63     TemporaryDirectory(Path directory) throws IOException {
64         mDirectory = Files.createDirectory(directory);
65     }
66 
TemporaryDirectory(@ullable String prefix)67     public TemporaryDirectory(@Nullable String prefix) throws IOException {
68         if (prefix == null) {
69             prefix = TemporaryDirectory.class.getSimpleName();
70         }
71         prefix += String.valueOf(SystemClock.elapsedRealtimeNanos());
72 
73         mDirectory = Files.createTempDirectory(prefix);
74     }
75 
76     @Override
close()77     public void close() throws Exception {
78         Files.walkFileTree(mDirectory, DELETE);
79     }
80 
getDirectory()81     public File getDirectory() {
82         return mDirectory.toFile();
83     }
84 
getPath()85     public Path getPath() { return mDirectory; }
86 
getSubdirectory(String name)87     public TemporaryDirectory getSubdirectory(String name) throws IOException {
88         return new TemporaryDirectory(mDirectory.resolve(name));
89     }
90 }
91