I’m Trying to Intercept Some Methods Using the Byte-Buddy Android Gradle Plugin

I want to intercept some methods using the Byte-Buddy Android Gradle plugin. Here are the versions I am using:

• Java version: 17
• Gradle version: 8.2.2
• ASM version: 9.6

I’ve tried many methods, but to keep it simple, I’ll share the example below.

public class TestClass {

    @Override
    public String toString() {
        return "TestClass{2}";
    }
}

I integrated the Gradle plugin, and it runs during compilation.

import net.bytebuddy.asm.AsmVisitorWrapper
import net.bytebuddy.build.Plugin
import net.bytebuddy.description.field.FieldDescription
import net.bytebuddy.description.field.FieldList
import net.bytebuddy.description.method.MethodList
import net.bytebuddy.description.type.TypeDescription
import net.bytebuddy.dynamic.ClassFileLocator
import net.bytebuddy.dynamic.DynamicType
import net.bytebuddy.implementation.Implementation
import net.bytebuddy.jar.asm.ClassVisitor
import net.bytebuddy.pool.TypePool
import org.objectweb.asm.Opcodes

class AnalyticsPlugin : Plugin {

    override fun matches(target: TypeDescription): Boolean {
        return target.canonicalName?.contains("TestClass") == true
    }

    override fun close() {}

    override fun apply(
        builder: DynamicType.Builder<*>,
        typeDescription: TypeDescription,
        classFileLocator: ClassFileLocator
    ): DynamicType.Builder<*> {
        // Intercept the toString method
        return builder.withToString()
    }
}

As a result of these operations, I get the following exception:

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:stageDebugBytebuddyTransform'.
> Failed to transform class com.app.ui.TestClass using com.app.analytics.compiler.AnalyticsPlugin@3260d700

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:stageDebugBytebuddyTransform'.
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.lambda$executeIfValid$1(ExecuteActionsTaskExecuter.java:148)
    ...
Caused by: java.lang.IllegalStateException: Failed to transform class com.app.ui.TestClass using com.app.analytics.compiler.AnalyticsPlugin@3260d700
    at net.bytebuddy.build.Plugin$Engine$ErrorHandler$Failing$1.onError(Plugin.java:1179)
    ...
Caused by: java.lang.UnsupportedOperationException: Cannot intercept method for decorated type: class com.app.ui.TestClass
    at net.bytebuddy.dynamic.scaffold.inline.DecoratingDynamicTypeBuilder.invokable(DecoratingDynamicTypeBuilder.java:445)
    at net.bytebuddy.dynamic.DynamicType$Builder$AbstractBase.invokable(DynamicType.java:3673)
    at net.bytebuddy.dynamic.DynamicType$Builder$AbstractBase.method(DynamicType.java:3659)
    at net.bytebuddy.dynamic.DynamicType$Builder$AbstractBase.withToString(DynamicType.java:3690)
    at com.app.analytics.compiler.AnalyticsPlugin.apply(AnalyticsPlugin.kt:44)
    ...

When I use the following code, I encounter the same issue:

builder.method(isAnnotatedWith(CallToAction::class.java))
       .intercept(MethodDelegation.to(Interceptor::class.java))

Is there any solution to this problem that i might be missing?