Android new build system (gradle) and aspectj

Question

In Google IO the new build system gradle is announced to replace ant. My project is using aspectj and I would like to use it in my project. I couldn\'t figure out some variabl

Answer 1

I also wanted to use aspectj with gradle and Android Studio, and I finally got it working, but I still have some hand-written paths that I'd like to replace with more generic gradle options.

Edit: I replaced every hard-coded absolute paths with gradle based alternatives, so this solution does not depend any more on a given platform or user name. However, it still uses relative paths that could change from an IDE to an other or in further releases of Android Studio. Also, I'm not really satisfied with the way I find the android.jar.

I first load aspectj:

configurations {
ajc
aspects
ajInpath
}

ext.aspectjVersion = '1.7.3'

dependencies {
    compile project(":LibTest")

    ajc "org.aspectj:aspectjtools:${aspectjVersion}"
    compile "org.aspectj:aspectjrt:${aspectjVersion}"
    compile 'com.android.support:appcompat-v7:18.0.0'
}

And I then add a task that will run after the JavaCompile task of the current variant:

android.applicationVariants.all { variant ->

    variant.javaCompile.doLast {
        def androidSdk = android.adbExe.parent + "/../platforms/" + android.compileSdkVersion + "/android.jar"

        def iajcClasspath = configurations.compile.asPath + ";" + androidSdk
        configurations.compile.dependencies.each { dep ->
            if(dep.hasProperty("dependencyProject")) {
                iajcClasspath += ":" + dep.dependencyProject.buildDir + "/bundles/release/classes.jar"
            }
        }

        ant.taskdef( resource:"org/aspectj/tools/ant/taskdefs/aspectjTaskdefs.properties", classpath: configurations.ajc.asPath)
        ant.iajc (
                source:sourceCompatibility,
                target:targetCompatibility,
                destDir:"${project.buildDir}/classes/${variant.dirName}",
                maxmem:"512m",
                fork:"true",
                aspectPath:configurations.aspects.asPath,
                inpath:configurations.ajInpath.asPath,
                sourceRootCopyFilter:"**/.svn/*,**/*.java",
                classpath:iajcClasspath
        ){
            sourceroots{
                android.sourceSets.main.java.srcDirs.each{
                    pathelement(location:it.absolutePath)
                }
                pathelement(location:"${project.buildDir}/source/r/${variant.dirName}")
            }
        }
    }
}

Wherever I use ${variant.dirName}, it will be replaced by either "debug" or "release" according to the current build configuration.

Adding android.jar to the classpath is required to compile Android specific classes, and the line pathelement(location:"${project.buildDir}/source/r/${variant.dirName}") is require to use classes from the auto-generated R.java file.

Edit: The iterations over the project dependencies to build iajcClasspath let you use classes from your libraries projects. configurations.compile.asPath already contains a reference to your apklib (aar file), which is actually a zip containing both the jar and the resources of the library. Iajc doesn't recognize these files as it, but there is a bundle directory containing the classes.jar for your library under the build directory. I use a relative path with "release" hard-coded in it, because the library has a different variant than the main project in my situation, so I can't use ${variant.dirName} here.

Here is the complete build.gradle file:

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.5.+'
    }
}
apply plugin: 'android'

repositories {
    mavenCentral()
}

android {
    compileSdkVersion 18
    buildToolsVersion "18.1.0"

    defaultConfig {
        minSdkVersion 7
        targetSdkVersion 18
    }
}

configurations {
    ajc
    aspects
    ajInpath
}

ext.aspectjVersion = '1.7.3'

dependencies {
    compile project(":LibTest")

    ajc "org.aspectj:aspectjtools:${aspectjVersion}"
    compile "org.aspectj:aspectjrt:${aspectjVersion}"
    compile 'com.android.support:appcompat-v7:18.0.0'
}

android.applicationVariants.all { variant ->

    variant.javaCompile.doLast {
        def androidSdk = android.adbExe.parent + "/../platforms/" + android.compileSdkVersion + "/android.jar"

        def iajcClasspath = configurations.compile.asPath + ";" + androidSdk
        configurations.compile.dependencies.each { dep ->
            if(dep.hasProperty("dependencyProject")) {
                iajcClasspath += ":" + dep.dependencyProject.buildDir + "/bundles/release/classes.jar"
            }
        }

        ant.taskdef( resource:"org/aspectj/tools/ant/taskdefs/aspectjTaskdefs.properties", classpath: configurations.ajc.asPath)
        ant.iajc (
                source:sourceCompatibility,
                target:targetCompatibility,
                destDir:"${project.buildDir}/classes/${variant.dirName}",
                maxmem:"512m",
                fork:"true",
                aspectPath:configurations.aspects.asPath,
                inpath:configurations.ajInpath.asPath,
                sourceRootCopyFilter:"**/.svn/*,**/*.java",
                classpath:iajcClasspath
        ){
            sourceroots{
                android.sourceSets.main.java.srcDirs.each{
                    pathelement(location:it.absolutePath)
                }
                pathelement(location:"${project.buildDir}/source/r/${variant.dirName}")
            }
        }
    }
}