深入探究Android动态代理的原理及用途

import java.lang.reflect.InvocationHandler
import java.lang.reflect.Method
import java.lang.reflect.Proxy
// 接口
interface MyInterface {
    fun doSomething()
}
// 实现类
class MyImplementation : MyInterface {
    override fun doSomething() {
        println("Original method is called.")
    }
}
// 调用处理器
class MyInvocationHandler(private val realObject: MyInterface) : InvocationHandler {
    override fun invoke(proxy: Any, method: Method, args: Array<Any?>?): Any? {
        println("Before method is called.")
        val result = method.invoke(realObject, *(args ?: emptyArray()))
        println("After method is called.")
        return result
    }
}
fun main() {
    val realObject = MyImplementation()
    val proxyObject = Proxy.newProxyInstance(
        MyInterface::class.java.classLoader,
        arrayOf(MyInterface::class.java),
        MyInvocationHandler(realObject)
    ) as MyInterface
    proxyObject.doSomething()
}

import android.util.Log
class PerformanceMonitorProxy(private val target: Any) : InvocationHandler {
    override fun invoke(proxy: Any, method: Method, args: Array<Any?>?): Any? {
        val startTime = System.currentTimeMillis()
        val result = method.invoke(target, *(args ?: emptyArray()))
        val endTime = System.currentTimeMillis()
        val duration = endTime - startTime
        Log.d("Performance", "${method.name} took $duration ms to execute.")
        return result
    }
}

import android.util.Log
import java.lang.reflect.InvocationHandler
import java.lang.reflect.Method
import java.lang.reflect.Proxy
import android.view.View
class ClickHandlerProxy(private val target: View.OnClickListener) : InvocationHandler {
    override fun invoke(proxy: Any, method: Method, args: Array<Any?>?): Any? {
        if (method.name == "onClick") {
            Log.d("ClickHandler", "Click event intercepted.")
            // 在事件处理前可以执行自定义逻辑
        }
        return method.invoke(target, *args.orEmpty())
    }
}
// 使用示例
val originalClickListener = View.OnClickListener {
    // 原始的点击事件处理逻辑
}
val proxyClickListener = Proxy.newProxyInstance(
    originalClickListener::class.java.classLoader,
    originalClickListener::class.java.interfaces,
    ClickHandlerProxy(originalClickListener)
) as View.OnClickListener
button.setOnClickListener(proxyClickListener)