1/*
2 * Copyright (C) 2007 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
17package com.android.dex.util;
18
19import java.io.File;
20import java.io.FileInputStream;
21import java.io.IOException;
22
23/**
24 * File I/O utilities.
25 */
26public final class FileUtils {
27    private FileUtils() {
28    }
29
30    /**
31     * Reads the named file, translating {@link IOException} to a
32     * {@link RuntimeException} of some sort.
33     *
34     * @param fileName {@code non-null;} name of the file to read
35     * @return {@code non-null;} contents of the file
36     */
37    public static byte[] readFile(String fileName) {
38        File file = new File(fileName);
39        return readFile(file);
40    }
41
42    /**
43     * Reads the given file, translating {@link IOException} to a
44     * {@link RuntimeException} of some sort.
45     *
46     * @param file {@code non-null;} the file to read
47     * @return {@code non-null;} contents of the file
48     */
49    public static byte[] readFile(File file) {
50        if (!file.exists()) {
51            throw new RuntimeException(file + ": file not found");
52        }
53
54        if (!file.isFile()) {
55            throw new RuntimeException(file + ": not a file");
56        }
57
58        if (!file.canRead()) {
59            throw new RuntimeException(file + ": file not readable");
60        }
61
62        long longLength = file.length();
63        int length = (int) longLength;
64        if (length != longLength) {
65            throw new RuntimeException(file + ": file too long");
66        }
67
68        byte[] result = new byte[length];
69
70        try {
71            FileInputStream in = new FileInputStream(file);
72            int at = 0;
73            while (length > 0) {
74                int amt = in.read(result, at, length);
75                if (amt == -1) {
76                    throw new RuntimeException(file + ": unexpected EOF");
77                }
78                at += amt;
79                length -= amt;
80            }
81            in.close();
82        } catch (IOException ex) {
83            throw new RuntimeException(file + ": trouble reading", ex);
84        }
85
86        return result;
87    }
88
89    /**
90     * Returns true if {@code fileName} names a .zip, .jar, or .apk.
91     */
92    public static boolean hasArchiveSuffix(String fileName) {
93        return fileName.endsWith(".zip")
94                || fileName.endsWith(".jar")
95                || fileName.endsWith(".apk");
96    }
97}
98