Dexter, the normal jar to dex jar handler

Dexter allows you to load jars and add them to your classpath so that you can use the classes held in them.

How it works

Android uses Dalvik byte code, it doesn’t work with normal jars. Before loading a normal jar, it has to be converted into a dex jar (a jar holding Dalvik byte code). This is the role of Dexter: it converts the jar into a dex jar (if needed) and then adds it to your classpath using the ClassPathHandler.

How to use

Start by using the import alias dex for simplicity

import dex

Load a jar

There are many ways to load a jar. If you don’t want to worry about the technical stuff, or don’t know if your jar is a dex jar or a normal one, just use the Dexter.loadFromFile()

Dexter.loadFromFile(file("groovy/fandem.jar"))
// you can then use classes from the jar
import com.tambapps.p2p.fandem.FileSharer
f = new FileSharer()

If you know what type of jar you’re dealing with, you can use the methods Dexter.loadFromDexFile() or Dexter.loadFromJarFile() to respectively load a normal jar or dex jar.

To help you recognize dex jar, there is the method Dexter.isDexJar(File)

You can also load a jar from an URL

Dexter.loadFromURL(new URL("https://some-url.com/to/a/library.jar"))

Convert a normal jar to a dex jar

You can convert a normal jar to a dex jar by providing an input file, the normal jar to be converted, and an output file, the destination file. The input and output file have to be different

originalJar = file("groovy/fandem.jar")
dexJar = file("groovy/fandem-dex.jar")
Dexter.convertJarToDexFile(originalJar, dexJar)