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.dx.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    /**
28     * This class is uninstantiable.
29     */
30    private FileUtils() {
31        // This space intentionally left blank.
32    }
33
34    /**
35     * Reads the named file, translating {@link IOException} to a
36     * {@link RuntimeException} of some sort.
37     *
38     * @param fileName {@code non-null;} name of the file to read
39     * @return {@code non-null;} contents of the file
40     */
41    public static byte[] readFile(String fileName) {
42        File file = new File(fileName);
43        return readFile(file);
44    }
45
46    /**
47     * Reads the given file, translating {@link IOException} to a
48     * {@link RuntimeException} of some sort.
49     *
50     * @param file {@code non-null;} the file to read
51     * @return {@code non-null;} contents of the file
52     */
53    public static byte[] readFile(File file) {
54        if (!file.exists()) {
55            throw new RuntimeException(file + ": file not found");
56        }
57
58        if (!file.isFile()) {
59            throw new RuntimeException(file + ": not a file");
60        }
61
62        if (!file.canRead()) {
63            throw new RuntimeException(file + ": file not readable");
64        }
65
66        long longLength = file.length();
67        int length = (int) longLength;
68        if (length != longLength) {
69            throw new RuntimeException(file + ": file too long");
70        }
71
72        byte[] result = new byte[length];
73
74        try {
75            FileInputStream in = new FileInputStream(file);
76            int at = 0;
77            while (length > 0) {
78                int amt = in.read(result, at, length);
79                if (amt == -1) {
80                    throw new RuntimeException(file + ": unexpected EOF");
81                }
82                at += amt;
83                length -= amt;
84            }
85            in.close();
86        } catch (IOException ex) {
87            throw new RuntimeException(file + ": trouble reading", ex);
88        }
89
90        return result;
91    }
92
93    /**
94     * Returns true if {@code fileName} names a .zip, .jar, or .apk.
95     */
96    public static boolean hasArchiveSuffix(String fileName) {
97        return fileName.endsWith(".zip")
98                || fileName.endsWith(".jar")
99                || fileName.endsWith(".apk");
100    }
101}
102