I wrote a library which has been uploaded to a private server. When I include the library as a dependency in my app project, and view the source code from one of the library classes, the source code isn't actually decompiled. It only shows the class name and methods. For example:
package com.example.library.ui
public final class RoundedDrawable public constructor() : android.graphics.drawable.Drawable {
public final var backgroundColor: kotlin.Int /* compiled code */
// ... other similar fields
public open fun draw(canvas: android.graphics.Canvas): kotlin.Unit { /* compiled code */ }
// ... other similar functions
}
As you can see, it only displays /* compiled code */ comments, and not the full source code. There is an option presented to "Decompile to Java"; which works, but I would much rather see the Kotlin source. Is this possible?
I found similar question that explains how to show the original Java code, but nothing for Kotlin.
Are you using Gradle?
You need to download sources for the library:
idea {
module {
downloadJavadoc = true
downloadSources = true
}
}
If attached sources/documentation are found, IntelliJ will use these when viewing .class files.
With Maven, you can do this from the tool window with Right click -> Download Sources
Other than that, decompiling a .class file to Kotlin is not possible with good results. Despector has a very rough Kotlin "decompiler".
When Releasing the library with maven publish, you can specify the source jar.
In this example, if your library is in Kotlin and Java, to add both source codes.
task androidSourcesJar(type: Jar) {
archiveClassifier = 'sources'
from (android.sourceSets.main.java.sourceFiles, android.sourceSets.main.kotlin.sourceFiles)
}
Related
I've written a .gradle script named publish.gradle which configures publishing {} for releasing my artifact.
Why on a separate script? I have multiple modules and by doing this every releasable module simply defines some variables.
Module build.gradle.kts:
// Module's blah blah
apply(from = "../publish.gradle")
publish.gradle:
apply plugin: 'maven-publish'
publishing {
publications {
// configure release process
}
}
I've recently decided to migrate to Gradle Kotlin DSL. However, there's an issue:
Adding publication {} like this:
plugins {
`maven-publish`
}
publication {
}
Lead to this error:
Expression 'publishing' cannot be invoked as a function. The function 'invoke()' is not found
Unresolved reference. None of the following candidates is applicable because of receiver type mismatch:
public val PluginDependenciesSpec.publishing: PluginDependencySpec defined in org.gradle.kotlin.ds
Which is summarized to
PluginDependenciesSpec is not present as a receiver
What is the difference?
TL; DR
I've added publishing {} config to a separate script which works when in .gradle groovy format but I can not convert to .gradle.kts kotlin format. The publishing is extension of PluginDependenciesSpec class which is not present in the script.
Here's what worked for me:
plugins {
id("maven-publish")
}
configure<PublishingExtension> {
publications.create<MavenPublication>("myPlugin") {
groupId = "com.myCompany.android"
artifactId = "MyPlugin"
version = "1.0.0"
pom.packaging = "jar"
artifact("$buildDir/libs/MyPlugin.jar")
}
repositories {
mavenLocal()
}
}
I understand where you're coming from, converting from groovy to kotlin script is not a simple one to one translation, and most of us, including myself, code by example. In other words, you just need to see a simple example and you can figure out the rest. This works great when examples are readily available. What you need to do when you don't find an example is to turn to the API document. For example, https://docs.gradle.org/current/dsl/org.gradle.api.publish.PublishingExtension.html shows you the available properties for the PublishingExtension and you can keep drilling in to see what properties you have at the next level. This is especially important when examples may be working with an older version and may no longer be applicable. I will say that it wasn't as obvious is that for accessing extensions in kotlin script, requires the configure block. That's a big difference, but I like that approach, because it makes it clearer what the extension properties are a part of. And by the way, kotlin wants double quote, single quotes are no longer acceptable.
I have an .aar third party library that I want to use in Xamarin Android. So I created a new Android Bindings Library, added the aar-library and changed the Build action of the aar file to LibraryProjectZip like described here: https://learn.microsoft.com/en-us/xamarin/android/platform/binding-java-library/binding-an-aar
Nothing else was changed and I would expect the project to compile and generate a dll file.
Instead I get a lot of errors saying Error CS0542 'xy': member names cannot be the same as their enclosing type.
When I jump to the origin of the error, I find the errors in generated code by Visual Studio with the classes looking something like:
public abstract class Albumin : Java.Lang.Object {
internal Albumin ()
{
}
// (removed for readability)
[Register ("ALBUMIN")]
public const string Albumin = (string) "albumin";
I cannot modify the source code of the library.
What can I do in order to build the Binding Library successfully?
Thank you very much #Leo Zhu for the answer in the comments:
The solution is Renaming Members.
So in my case the Metadata.xml in die Binings Library would look like the following:
<attr path="/api/package[#name='com.company.android.sdk.dataclass']/interface[#name='DataClass.Albumin']/field[#name='ALBUMIN']" name="name">ALBUMIN_Binding</attr>
I've been trying to write a library in kotlin and once the library build is generated as aar file when opening it in Android Studio it is not showing me how my class exactly looks and how the methods are implemented in that.
// IntelliJ API Decompiler stub source generated from a class file
// Implementation of methods is not available
package com.mypackage.dexter
public final class Test private constructor() {
public final fun testMethod(): kotlin.Unit { /* compiled code */ }
}
I've tried Java decompiler plugin in android studio, Kotlin Byte code (This also doesn't show it in the same format that we get if the same code is written in Java). The ultimate thing that I wanted to achieve by looking at the code is that I want to use debugger in the library and evaluate things while running my application where this library is integrated.
What I'm trying to achieve
I'm trying to generate my REST API client for Android using OpenAPI Generator from the build.gradle script. That way, I wouldn't have to run the generator command line every time the specs change. Ideally, this would be generated when I build/assemble my app, and the sources would end up in the java (generated) folder, where generated sources are then accessible from the code (this is what happens with the BuildConfig.java file for example).
What I've tried so far
Following this link from their official GitHub, here's the build.gradle file I ended up with:
apply plugin: 'com.android.application'
apply plugin: 'org.openapi.generator'
...
openApiValidate {
inputSpec = "$rootDir/app/src/main/openapi/my-api.yaml"
recommend = true
}
openApiGenerate {
generatorName = "java"
inputSpec = "$rootDir/app/src/main/openapi/my-api.yaml"
outputDir = "$buildDir/generated/openapi"
groupId = "$project.group"
id = "$project.name-openapi"
version = "$project.version"
apiPackage = "com.example.mypackage.api"
invokerPackage = "com.example.mypackage.invoker"
modelPackage = "com.example.mypackage.model"
configOptions = [
java8 : "true",
dateLibrary : "java8",
library : "retrofit2"
]
}
...
First, I've never managed to get the API generated with the build/assemble task, even when I tried adding:
compileJava.dependsOn tasks.openApiGenerate
or
assemble.dependsOn tasks.openApiGenerate
The only way I could generate the sources was by manually triggering the openApiGenerate task:
Then, when I do generate my sources this way, they end up in the build folder but aren't accessible from my code, and aren't visible in the java (generated) folder:
I then have to manually copy/paste the generated source files to my project sources in order to use the API.
Even though I'm able to work around these issues by adding manual procedures, it would be way more maintainable if the whole process was simply automatic. I was able to achieve a similar result with another tool, Protobuf. Indeed, my gradle task gets triggered every time I build the app, and the sources end up in the java (generated) folder, so I don't have to do any additional work. The task is much simpler though, so I assume the main work that I'm not able to replicate with OpenAPI Generator is handled by the Protobuf plugin itself.
You have to specify path to the generated sources as a custom source set for your Gradle module, which is app in this case, as described here – https://developer.android.com/studio/build/build-variants#configure-sourcesets. That way Gradle will treat your sources as accessible from your code.
Something like this:
android {
...
sourceSets {
main {
java.srcDirs = ['build/generated/openapi/src/main/java']
}
}
...
}
I solved the issue you described like this, I'm using gradle.kts however.
See my build.gradle.kts
plugins {
// Your other plugins
id("org.openapi.generator") version "5.3.0"
}
openApiGenerate {
generatorName.set("kotlin")
inputSpec.set("$rootDir/app/src/main/openapi/my-api.yaml")
outputDir.set("$buildDir/generated/api")
// Your other specification
}
application {
// Your other code
sourceSets {
main {
java {
// TODO: Set this path according to what was generated for you
srcDir("$buildDir/generated/api/src/main/kotlin")
}
}
}
}
tasks.compileKotlin {
dependsOn(tasks.openApiGenerate)
}
You need to build the application at least once for the IDE to detect the library (at least this is the case for me in Intellij)
Your build should automatically generate the open api classes , to refer the generated classes in your java project you should add the generated class path to your source directory like it was mentioned in the other answers
https://developer.android.com/studio/build/build-variants#configure-sourcesets
As far as the task dependency goes , in android tasks are generated after configuration thus for gradle to recognize the task , wrap it inside afterEvaluate block like
afterEvaluate {
tasks.compileDebugJavaWithJavac.dependsOn(tasks.openApiGenerate)
}
I had this issue, and this answer https://stackoverflow.com/a/55646891/14111809 led me to a more informative error:
error: incompatible types: Object cannot be converted to Annotation
#java.lang.Object()
Taking a look at the generated files that were causing this error, noticed:
import com.squareup.moshi.Json;
After including a Moshi in the app build.gradle, the build succeeded and the generated code was accessible.
implementation("com.squareup.moshi:moshi-kotlin:1.13.0")
As per the introduction of Custom Class Loading in Dalvik by Fred Chung on the Android Developers Blog:
The Dalvik VM provides facilities for developers to perform custom
class loading. Instead of loading Dalvik executable (“dex”) files from
the default location, an application can load them from alternative
locations such as internal storage or over the network.
However, not many developers have the need to do custom class loading. But those who do and follow the instructions on that blog post, might have some problems mimicking the same behavior with Gradle, the new build system for Android introduced in Google I/O 2013.
How exactly one can adapt the new build system to perform the same intermediary steps as in the old (Ant based) build system?
My team and I recently reached the 64K method references in our app, which is the maximum number of supported in a dex file. To get around this limitation, we need to partition part of the program into multiple secondary dex files, and load them at runtime.
We followed the blog post mentioned in the question for the old, Ant based, build system and everything was working just fine. But we recently felt the need to move to the new build system, based on Gradle.
This answer does not intend to replace the full blog post with a complete example. Instead, it will simply explain how to use Gradle to tweak the build process and achieve the same thing. Please note that this is probably just one way of doing it and how we are currently doing it in our team. It doesn't necessarily mean it's the only way.
Our project is structured a little different and this example works as an individual Java project that will compile all the source code into .class files, assemble them into a single .dex file and to finish, package that single .dex file into a .jar file.
Let's start...
In the root build.gradle we have the following piece of code to define some defaults:
ext.androidSdkDir = System.env.ANDROID_HOME
if(androidSdkDir == null) {
Properties localProps = new Properties()
localProps.load(new FileInputStream(file('local.properties')))
ext.androidSdkDir = localProps['sdk.dir']
}
ext.buildToolsVersion = '18.0.1'
ext.compileSdkVersion = 18
We need the code above because although the example is an individual Java project, we still need to use components from the Android SDK. And we will also be needing some of the other properties later on... So, on the build.gradle of the main project, we have this dependency:
dependencies {
compile files("${androidSdkDir}/platforms/android-${compileSdkVersion}/android.jar")
}
We are also simplifying the source sets of this project, which might not be necessary for your project:
sourceSets {
main {
java.srcDirs = ['src']
}
}
Next, we change the default configuration of the build-in jar task to simply include the classes.dex file instead of all .class files:
configure(jar) {
include 'classes.dex'
}
Now we need to have new task that will actually assemble all .class files into a single .dex file. In our case, we also need to include the Protobuf library JAR into the .dex file. So I'm including that in the example here:
task dexClasses << {
String protobufJarPath = ''
String cmdExt = Os.isFamily(Os.FAMILY_WINDOWS) ? '.bat' : ''
configurations.compile.files.find {
if(it.name.startsWith('protobuf-java')) {
protobufJarPath = it.path
}
}
exec {
commandLine "${androidSdkDir}/build-tools/${buildToolsVersion}/dx${cmdExt}", '--dex',
"--output=${buildDir}/classes/main/classes.dex",
"${buildDir}/classes/main", "${protobufJarPath}"
}
}
Also, make sure you have the following import somewhere (usually at the top, of course) on your build.gradle file:
import org.apache.tools.ant.taskdefs.condition.Os
Now we must make the jar task depend on our dexClasses task, to make sure that our task is executed before the final .jar file is assembled. We do that with a simple line of code:
jar.dependsOn(dexClasses)
And we're done... Simply invoke Gradle with the usual assemble task and your final .jar file, ${buildDir}/libs/${archivesBaseName}.jar will contain a single classes.dex file (besides the MANIFEST.MF file). Just copy that into your app assets folder (you can always automate that with Gradle as we've done but that is out of scope of this question) and follow the rest of the blog post.
If you have any questions, just shout in the comments. I'll try to help to the best of my abilities.
The Android Studio Gradle plugin now provides native multidex support, which effectively solves the Android 65k method limit without having to manually load classes from a jar file, and thus makes Fred Chung's blog obsolete for that purpose. However, loading custom classes from a jar file at runtime in Android is still useful for the purpose of extensibility (e.g. making a plugin framework for your app), so I'll address that usage scenario below:
I have created a port of the original example app on Fred Chung's blog to Android Studio on my github page over here using the Android library plugin rather than the Java plugin. Instead of trying to modify the existing dex process to split up into two modules like in the blog, I've put the code which we want to go into the jar file into its own module, and added a custom task assembleExternalJar which dexes the necessary class files after the main assemble task has finished.
Here is relevant part of the build.gradle file for the library. If your library module has any dependencies which are not in the main project then you will probably need to modify this script to add them.
apply plugin: 'com.android.library'
// ... see github project for the full build.gradle file
// Define some tasks which are used in the build process
task copyClasses(type: Copy) { // Copy the assembled *.class files for only the current namespace into a new directory
// get directory for current namespace (PLUGIN_NAMESPACE = 'com.example.toastlib')
def namespacePath = PLUGIN_NAMESPACE.replaceAll("\\.","/")
// set source and destination directories
from "build/intermediates/classes/release/${namespacePath}/"
into "build/intermediates/dex/${namespacePath}/"
// exclude classes which don't have a corresponding .java entry in the source directory
def remExt = { name -> name.lastIndexOf('.').with {it != -1 ? name[0..<it] : name} }
eachFile {details ->
def thisFile = new File("${projectDir}/src/main/java/${namespacePath}/", remExt(details.name)+".java")
if (!(thisFile.exists())) {
details.exclude()
}
}
}
task assembleExternalJar << {
// Get the location of the Android SDK
ext.androidSdkDir = System.env.ANDROID_HOME
if(androidSdkDir == null) {
Properties localProps = new Properties()
localProps.load(new FileInputStream(file('local.properties')))
ext.androidSdkDir = localProps['sdk.dir']
}
// Make sure no existing jar file exists as this will cause dx to fail
new File("${buildDir}/intermediates/dex/${PLUGIN_NAMESPACE}.jar").delete();
// Use command line dx utility to convert *.class files into classes.dex inside jar archive
String cmdExt = Os.isFamily(Os.FAMILY_WINDOWS) ? '.bat' : ''
exec {
commandLine "${androidSdkDir}/build-tools/${BUILD_TOOLS_VERSION}/dx${cmdExt}", '--dex',
"--output=${buildDir}/intermediates/dex/${PLUGIN_NAMESPACE}.jar",
"${buildDir}/intermediates/dex/"
}
copyJarToOutputs.execute()
}
task copyJarToOutputs(type: Copy) {
// Copy the built jar archive to the outputs folder
from 'build/intermediates/dex/'
into 'build/outputs/'
include '*.jar'
}
// Set the dependencies of the build tasks so that assembleExternalJar does a complete build
copyClasses.dependsOn(assemble)
assembleExternalJar.dependsOn(copyClasses)
For more detailed information see the full source code for the sample app on my github.
See my answer over here. The key points are:
Use the additionalParameters property on the dynamically created dexCamelCase tasks to pass --multi-dex to dx and create multiple dex files.
Use the multidex class loader to use the multiple dex files.