decompiling DEX into Java sourcecode

Question

How can one decompile Android DEX (VM bytecode) files into corresponding Java sourcecode?

Answer 1

Since Dheeraj Bhaskar's answer is relatively old as many years past.

Here is my latest (2019 year) answer:

Main Logic

from dex to java sourcecode, currently has two kind of solution:

• One Step: directly convert dex to java sourcecode
• Two Step: first convert dex to jar, second convert jar to java sourcecode

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One step solution: dex directly to java sourcecode

Tools

• jadx

Process

1. download jadx-0.9.0.zip, unzip it, in bin folder can see command line jadx or GUI version jadx-gui, double click to run GUI version: jadx-gui

2. open dex file

then can show java source code:

3. File -> save as gradle project

then got java sourcecode:

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Two Step solution

Step1: dex to jar

Tools

• dex2jar

Process

download dex2jar zip, unzip got d2j-dex2jar.sh, then:

• apk to jar: sh d2j-dex2jar.sh -f ~/path/to/apk_to_decompile.apk
• dex to jar: sh d2j-dex2jar.sh -f ~/path/to/dex_to_decompile.dex

example:

➜  v3.4.8 /Users/crifan/dev/dev_tool/android/reverse_engineering/dex-tools/dex-tools-2.1-SNAPSHOT/d2j-dex2jar.sh -f com.huili.readingclub8825612.dex
dex2jar com.huili.readingclub8825612.dex -> ./com.huili.readingclub8825612-dex2jar.jar
➜  v3.4.8 ll
-rw-------  1 crifan  staff   9.5M  3 21 10:00 com.huili.readingclub8825612-dex2jar.jar
-rw-------  1 crifan  staff   8.4M  3 19 14:04 com.huili.readingclub8825612.dex

Step2: jar to java sourcecode

Tools

• jd-gui: most popular, but many code will decompile error
• CRF: popular, minor code will decompile error
• Procyon: popular, no code decompile error
  • GUI tool based on Procyon
    • Luyten:
    • Bytecode Viewer
• others
  • Krakatau
  • Fernflower
  • old one: AndroChef
  • etc.

Process

here demo Procyon convert jar to java source code:

download procyon-decompiler-0.5.34.jar

then using syntax:

java -jar /path/to/procyon-decompiler-0.5.34.jar -jar your_to_decompile.jar -o outputFolderName

example:

java -jar /Users/crifan/dev/dev_tool/android/reverse_engineering/Procyon/procyon-decompiler-0.5.34.jar -jar com.huili.readingclub8825612-dex2jar.jar -o com.huili.readingclub8825612

using editor VSCode to open exported source code, look like this:

Conclusion

Conversion correctness : Jadx > Procyon > CRF > JD-GUI

Recommend use: (One step solution's) Jadx

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for more detailed explanation, please refer my online Chinese ebook: 安卓应用的安全和破解