I am writing a Gradle plugin that needs to scan Kotlin files and find if there is a certain interface included in the class. For example, with this snippet of code:
class MyClass {
interface MyInterface {
fun doSomething()
}
}
my plugin would print on the console that the interface MyInterface was found, and for this snippet:
class MySecondClass {}
would not print anything.
I have successfully created the plugin structure and a DefaultTask like this, where I get the file that needs to be inspected from the user input (written in Kotlin):
open class MyGradleTas : DefaultTask() {
#InputFile lateinit var inputFile: File
#OutputDirectory lateinit var outputDirectory: File
#TaskAction
fun run() {
// How can I inspect the Java/Kotlin code inside the inputFile object
}
}
How can I inspect the inputFile File object? Is there a way to transform it to UAST or PSI? If so, how?
So I found this project: http://javaparser.org/ that I believe it will put me in the right direction, but any suggestions are welcome, since I do not know if this is the preferred/right approach
I agree with your thought that using a parser is the correct way to approach this. I found a discussion of parsing Kotlin that has pointers to 2 projects on GitHub that use antlr4 grammars to parse Kotlin. The second project appears to be basically a copy of the first, but provides slightly more useful examples of how to use it.
Related
i wanted to write a bit for Android ebay client.
but im struggeling with the first probleme.
first i start a new Java Android Project with IntelliJ
I want to use this Library ebay-oauth-android-client
like described on Git:
Obtaining Library
This library is distributed via maven central repository. To use this
library, include the below as dependency in your project
dependencies {
compile 'com.ebay.auth:ebay-oauth-android-client:1.0.1'
}
i put this snippet in my Gradle.build and replace compile with implementation since compile is depricated.
so far so good. gradle import this library.
but the next step not working for me:
Application Setup
Before performing OAuth, the library should be initialized with details about your application from eBay developer portal. The library uses
Client ID. For details see Getting your OAuth credentials
Redirect Uri. for details see Getting your Redirect_Uri
Url encoded list of scopes. for details see Specifying OAuth scopes
Use these details in ApiSessionConfiguration.initialize() as shown below:
ApiSessionConfiguration.initialize(
apiEnvironment = ApiEnvironment.PRODUCTION,
apiConfiguration = ApiConfiguration(
<Client ID>,
<Redirect Uri>,
<space separated scopes>
)
)
So i try to call initialze:
my Code with error
But when i try that the Compiler tells me that:
cannot find symbol method initialize(<null>)
When i Jump to the Class Declaration of ApiSessionConfiguration is written that:
// IntelliJ API Decompiler stub source generated from a class file
// Implementation of methods is not available
package com.ebay.api.client.auth.oauth2.model
public final class ApiSessionConfiguration private constructor() {
public companion object {
private final val instance: com.ebay.api.client.auth.oauth2.model.ApiSessionConfiguration /* compiled code */
public final fun getInstance(): com.ebay.api.client.auth.oauth2.model.ApiSessionConfiguration { /* compiled code */ }
public final fun initialize(apiEnvironment: com.ebay.api.client.auth.oauth2.model.ApiEnvironment, apiConfiguration: com.ebay.api.client.auth.oauth2.model.ApiConfiguration): com.ebay.api.client.auth.oauth2.model.ApiSessionConfiguration { /* compiled code */ }
}
public final var apiConfiguration: com.ebay.api.client.auth.oauth2.model.ApiConfiguration? /* compiled code */
public final var apiEnvironment: com.ebay.api.client.auth.oauth2.model.ApiEnvironment? /* compiled code */
}
i dont really understand what im doing wrong. in the sample file on Git ApiSessionConfiguration.initalize() is called without any errors.
i already tried to Invalidate Cache, Clean Build, and start over again.
when i try to import the library from Project Structure Librarys New from Maven repo it says:
no files were downloaded...
Doesn't it can resolve initialize method with single argument?
Did you tried initialize method with two arguments?
Their sample app takes 2 arguments:
https://github.com/eBay/ebay-oauth-android-client/blob/master/sample/src/main/java/com/ebay/api/client/auth/MainActivity.kt#L37-L44
Updated:
But to access to Kotlin companion object function from java you need to call ApiSessionConfiguration.Companion.initialize method
I have built a jar from my Scala project.
I have the following structure for what I want to use from this jar
package aaa.bbb.ccc
case class FooResult(...)
trait Foo(...) {
def bar(): FooResult
}
object Foo {
private class FooImpl(...) extends Foo {
...
}
def apply(...): Foo
}
First question: Maybe I have misunderstood something in what Py4J offers,
but do I have to write a java/scala class to start the Py4J gateway if I want to use my own classes? Or is it enough to add it to the gateway's jvm's classpath?
Second question (which I guess doesn't apply depending on the answer to above): How do I add my jar when starting the java gateway in order to make it available? To solve this temporarily, I just started the jvm manually with my jar along with the Py4J jar with this command
java -classpath "path/to/py4j.jar:path/to/my.jar" py4j.GatewayServer 0
and then connected to it manually from the Python code. Then I tried to import my classes via
java_import(gateway.jvm, "aaa.bbb.ccc.*")
which didn't throw any error but I'm not sure it worked because it doesn't throw any error if I input some fake classpath.
Third question (which applies if the answer to the first is that I have to write the entry point to access my classes): How does this work when using scala?
object Main extends App {
val gw = new GatewayServer(// TODO: how to expose my classes here?
}
I've got some class with property marked as internal.
Then I try to set that property from test code which is in java.
How can I access those properties? test code and class code are in the same package.
example:
class MainActivity : AppCompatActivity() {
interal var someProperty = "test"
}
test code:
#Test
public void firstStartTest() {
val activity = MainActivity()
activity.setSomeProperty("something") //does not compile
}
Android Studio is suggesting activity.setSomeProperty$production_sources_for_module_app();
but this also does not compile.
Both classes (MainActivity and test class) must be in one module. This is a module definition:
More specifically, a module is a set of Kotlin files compiled together:
an IntelliJ IDEA module;
a Maven or Gradle project;
a set of files
compiled with one invocation of the Ant task.
https://kotlinlang.org/docs/reference/visibility-modifiers.html
It means, check your project structure.
add #JvmField annotation.
It treats variable as java protected
There are two ways of doing this:
Make the property protected. Note on how Java & Kotlin treat protected differently. In Java it's possible that other classes in the same package access protected members. Thus your test class (in Java) can access it.
Access the property via its ugly name. It should be sort of like activity.setSomeProperty$production_.... Make use the autocomplete. From the documentation:
Members of internal classes go through name mangling, to make it
harder to accidentally use them from Java and to allow overloading for
members with the same signature that don't see each other according to
Kotlin rules;
Im trying to use Scala and Java in one project. Im working with the Scla IDE for Eclipse. I have two packages in my Scala Project: one for my scala code and one for my java code.
Now lets say I create new JavaClass with one static member.
package javastuff;
public class MyJavaClass {
public static String MESSAGE = "Im Java";
}
After that Im trying to get access to this variale and somehow I cannot. Funny thing, because scala is able to see the Java class "MyJavaClass" just not able to see MESSAGE.
import javastuff.MyJavaClass
object Main {
def main(args: Array[String]) {
println(MyJavaClass.MESSAGE)
}
}
Value MESSAGE is not a member of object javastuff.MyJavaClass
If I use Project/Clean... 1-2x times eclipse is maybe starting realizing that the member MESSAGE is really there and everything is fine. Is this normal? Maybe Im doing something wrong, I know eclipse is really a bad IDE and I should maybe try IntelliJ, but somehow I like eclipse and I would like to use later some of my favorite plugins, thats why I would not change the IDE just because of this problem. Any ideas how to handle this problem better?
Scala doesn't have any static fields. Here is a blogpost about it
btw. public static without final is pretty bad design (no encapsulation => possible memory leaks)
By running System.loadLibrary("myAPI"), I verified that the DLL file "myAPI.dll" can be successfully loaded into my Eclipse Java project. Now I need to call methods specified inside this DLL file from my Java code. To do this, I added JNA to my Java project. Then I wrote the below-given code snippet that should be able to get instances of classes IProject and ProjectFactory (specified in the DLL file).
I still don't understand how to properly implement this with JNA. I checked different threads, e.g. this one, but the ones I checked don't provide an answer. Any help is highly appreciated. Thanks.
import com.sun.jna.Library;
import com.sun.jna.Native;
public class MyClass {
public interface myAPI extends Library {
//...
}
void LoadProj() {
myAPI api = (myAPI) Native.loadLibrary("myAPI",myAPI.class);
String fileName = "xxx.sp";
IProject project; // this is wrong but shows what I am trying to do
try {
project = ProjectFactory.LoadProject(fileName);
}
catch (Exception ex) {
MessageBox.Show(this, ex.Message, "Load failure");
}
}
}
Not sure what problem you are facing but as a practice your myAPI interface should declare all the methods verbatim with appropriate parameter mapping. I don't see any methods inside your interface.
Please checkout the this link as well as the link mentioned above by #Perception
If there are no Java classes or Java source hidden inside this DLL (which would be ... strange), then it will never work this way. You can't instantiate C# classes or use C# interfaces. MessageBox.Show( isn't Java either, it is Windows Forms code.