[TOC]
问题
1.动态代理使用Kotlin书写报错
描述
Process: com.y.hookdemo, PID: 24014
java.lang.IllegalArgumentException: method android.app.IActivityManager$Stub$Proxy.getActivityDisplayId argument 1 has type android.os.IBinder, got java.lang.Object[]
at java.lang.reflect.Method.invoke(Native Method)
at com.y.hookdemo.HookUtil$HookInvocationHandler.invoke(HookUtil.kt:121)
- kotlin书写：
private class HookInvocationHandler(private val iam: Any): InvocationHandler {
@Throws(Throwable::class)
override fun invoke(proxy: Any, method: Method, args: Array<Any>): Any {
if (method.name.contains("startActivity")) {
Log.e("Hook", "IActivityManager动态代理的invoke方法,伪装intent")
for (i in args.indices) {
if (args[i] is Intent) {
val intent = args[i] as Intent
val proxyIntent = Intent(mContext, ProxyActivity::class.java)
proxyIntent.putExtra("intent", intent)
args[i] = proxyIntent
break
}
}
}
return method.invoke(iam, args)
}
}
报错在 return method.invoke(iam, args) 这一行，用java写正常执行
- java书写：
private class HookInvocationHandler implements InvocationHandler {
private Object iam;
private HookInvocationHandler(Object iam) {
this.iam = iam;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
if (method.getName().contains("startActivity")) {
Log.e("Hook", "IActivityManager动态代理的invoke方法,伪装intent");
for (int i = 0; i < args.length; i++) {
if (args[i] instanceof Intent) {
Intent intent = (Intent) args[i];
Intent proxyIntent = new Intent(mContext, ProxyActivity.class);
proxyIntent.putExtra("intent", intent);
args[i] = proxyIntent;
break;
}
}
}
return method.invoke(iam, args);
}
}
将java通过as转为kotlin，这行变为
return method.invoke(iam, *args)
思考
@CallerSensitive
// Android-changed: invoke(Object, Object...) implemented natively.
@FastNative
public native Object invoke(Object obj, Object... args)
throws IllegalAccessException, IllegalArgumentException, InvocationTargetException;
反射api中Method的invoke方法接收可变长参数，在java中允许数组赋值给可变长参数Object... args，Kotlin中，数组是array，可变长参数类型是vararg，类型不一致，所以method.invoke(iam, args),是两个参数，第二个参数是数组，实际方法需要多个参数，第二个参数是IBinder，所以报第一个错。
Kotlin中数组转为可变长参数，是通过前面加*，所以as把java转为kotlin后，变为method.invoke(iam, *args),参数正确，但依旧报第二个错.
com.y.hookdemo E/AndroidRuntime: Error reporting crash
java.lang.IllegalStateException: method.invoke(iam, *args) must not be null
at com.y.hookdemo.HookUtil$HookInvocationHandler.invoke(HookUtil.kt:121)
at java.lang.reflect.Proxy.invoke(Proxy.java:913)
???
解决
解决毛，谷歌吹个毛的java和kotlin可以一起用，改用java写了
kotlin书写时，返回值是Any，方法可能是没有返回值的，所以修改为Any？，然后修改
private class HookInvocationHandler(private val iam: Any): InvocationHandler {
@Throws(Throwable::class)
override fun invoke(proxy: Any, method: Method, args: Array<Any>): Any? {
if (method.name.contains("startActivity")) {
Log.e("Hook", "IActivityManager动态代理的invoke方法,伪装intent")
for (i in args.indices) {
if (args[i] is Intent) {
val intent = args[i] as Intent
val proxyIntent = Intent(mContext, ProxyActivity::class.java)
proxyIntent.putExtra("intent", intent)
args[i] = proxyIntent
break
}
}
}
val res = method.invoke(iam, *args)
Log.e("------a1:${method.name}",args.size.toString())
Log.e("res = ",res?.toString() + "--")
Log.e("returnType:",method.genericReturnType.typeName)
return if("void" == method.genericReturnType.typeName) Unit else res
}
}
正常运行
- 新的问题
java书写时返回值为Object，执行没有返回值的method时，为什么可以
