DexFileFactory.java revision 84c1762a62d7fc6638432c6c56e0422aa8cc6939 
1/*
2 * Copyright 2012, Google Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 *     * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *     * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 *     * Neither the name of Google Inc. nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32package org.jf.dexlib2;
33
34import com.google.common.io.ByteStreams;
35import com.google.common.io.Files;
36import org.jf.dexlib2.dexbacked.DexBackedDexFile;
37import org.jf.dexlib2.iface.DexFile;
38import org.jf.util.ExceptionWithContext;
39
40import javax.annotation.Nonnull;
41import java.io.File;
42import java.io.IOException;
43import java.util.zip.ZipEntry;
44import java.util.zip.ZipFile;
45
46public final class DexFileFactory {
47    @Nonnull
48    public static DexFile loadDexFile(String path) throws IOException {
49        return loadDexFile(new File(path));
50    }
51
52    @Nonnull
53    public static DexFile loadDexFile(File dexFile) throws IOException {
54        boolean isZipFile = false;
55        byte[] dexBytes = null;
56        ZipFile zipFile = null;
57        boolean zipSuccess = false;
58        try {
59            zipFile = new ZipFile(dexFile);
60            // if we get here, it's safe to assume we have a zip file
61            isZipFile = true;
62
63            ZipEntry zipEntry = zipFile.getEntry("classes.dex");
64            if (zipEntry == null) {
65                throw new ExceptionWithContext("zip file %s does not contain a classes.dex file", dexFile.getName());
66            }
67            long fileLength = zipEntry.getSize();
68            if (fileLength < 40) {
69                throw new ExceptionWithContext(
70                        "The classes.dex file in %s is too small to be a valid dex file", dexFile.getName());
71            } else if (fileLength > Integer.MAX_VALUE) {
72                throw new ExceptionWithContext("The classes.dex file in %s is too large to read in", dexFile.getName());
73            }
74            dexBytes = new byte[(int)fileLength];
75            ByteStreams.readFully(zipFile.getInputStream(zipEntry), dexBytes);
76            zipSuccess = true;
77        } catch (IOException ex) {
78            if (isZipFile) {
79                throw ex;
80            }
81        } finally {
82            if (zipFile != null) {
83                try {
84                    zipFile.close();
85                } catch (IOException ex) {
86                    // just eat it
87                }
88            }
89        }
90
91        if (!zipSuccess) {
92            // nope, it doesn't looks like a zip file. Let's see if it's a dex file
93            dexBytes = Files.toByteArray(dexFile);
94        }
95
96        return new DexBackedDexFile.Impl(dexBytes);
97    }
98
99    public static void writeDexFile(String path, DexFile dexFile) throws IOException {
100        org.jf.dexlib2.writer.DexFile.writeTo(path, dexFile);
101    }
102
103    private DexFileFactory() {}
104}
105