arashvscode/zipalign-java

zipalign implemented as a java library

zipalign-java

Zipalign implemented in java with 0 dependencies.

Note: zip64 is currently unsupported, this may not work on apks with the size bigger than 4GB.

Using

It is highly recommended to use a RandomAccessFile as the zip input.

import com.iyxan23.zipalignjava.ZipAlign;

RandomAccessFile zipIn = new RandomAccessFile(zipPath, "r");
FileOutputStream zipOut = ...;

ZipAlign.alignZip(zipIn, zipOut);

or if you really need it, you can read from an InputStream. Do note that this is substantially slower than using RandomAccessFile.

import com.iyxan23.zipalignjava.ZipAlign;

FileInputStream zipIn = ...;
FileOutputStream zipOut = ...;

ZipAlign.alignZip(zipIn, zipOut);

Importing

You can use this library by importing this as a gradle module to your project, building a jar, or just by copying the classes.

Building a jar

To build a jar, run:

$ ./gradlew jar

and you'll have a built jar in the build/libs directory.

This jar will contain a very simple cli that allows you to run it in your command line.

$ java -jar zipalign-java-0.1-dev.jar input.zip output.zip

Benchmarks

These benchmarks are ran on an AMD Ryzen 5-5500U CPU with IntelliJ IDEA's runner and Temurin JDK 18.

Function                                             Avg elapsed time   Input

ZipAlign#alignZip(RandomAccessFile, OutputStream)    28ms               File from https://github.com/Iyxan23/zipalign-java/issues/1#issue-1236875761 (270K)
ZipAlign#alignZip(InputStream, OutputStream)         497ms              -- same file --