Awesome

Zipalign implemented in java without any dependencies. Read my post about it :>

Using

Pass in a RandomAccessFile to the function ZipAlign#alignZip to provide ZipAlign with a seekable file for more performant aligning.

import com.iyxan23.zipalignjava.ZipAlign;

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

ZipAlign.alignZip(zipIn, zipOut);

Additionaly, you could use a regular InputStream (caution: terribly slow)

import com.iyxan23.zipalignjava.ZipAlign;

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

ZipAlign.alignZip(zipIn, zipOut);

[!WARNING] The InputStream API is deprecated and is not supported anymore, it does not support aligning .so files and will not be.

Aligning .so files to 16KiB page boundaries is enabled by default, pass in a boolean to opt out:

// only if zipIn is a RandomAccessFile
ZipAlign.alignZip(zipIn, zipOut, false);

Prefer to align .so files in a 4KiB page boundaries?

// only if zipIn is a RandomAccessFile
ZipAlign.alignZip(zipIn, zipOut, 4, 4096);

Importing

This library is published in jitpack, you can add it as your dependency it with:

allprojects {
    repositories {
        mavenCentral()
        maven { url "https://jitpack.io" }
    }
}

dependencies {
    implementation 'com.github.iyxan23:zipalign-java:1.2.0'
}

You could also use prebuilt jars by the CI or in the releases section.

The jar contains a simple CLI that allows you to use it in the command line.

$ java -jar zipalign-java-1.2.0.jar input.zip output.zip

Benchmarks

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 --