问题
I'm trying to call an android internal method to reboot the device. It's just an experiment, I would try to understand what I'm doing wrong. I know there are probably better methods to reboot (involving busybox?).
Class watchdogClass = Class.forName("com.android.server.Watchdog");
Method getInstance = watchdogClass.getDeclaredMethod("getInstance");
Method rebootSystem = watchdogClass.getDeclaredMethod("rebootSystem", String.class);
Object watchdogInstance = getInstance.invoke(null);
rebootSystem.invoke(watchdogInstance, "my reboot message");
This is the exception I get, I googled without finding a solution.
helloroot I/Watchdog﹕ Rebooting system because: my reboot message
helloroot W/System.err﹕ java.lang.reflect.InvocationTargetException
helloroot W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
helloroot W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:515)
helloroot W/System.err﹕ at org.example.helloroot.SettingsActivity.onPostCreate(SettingsActivity.java:80)
helloroot W/System.err﹕ at android.app.Instrumentation.callActivityOnPostCreate(Instrumentation.java:1150)
helloroot W/System.err﹕ at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2188)
helloroot W/System.err﹕ at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2271)
helloroot W/System.err﹕ at android.app.ActivityThread.access$800(ActivityThread.java:144)
helloroot W/System.err﹕ at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
helloroot W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:102)
helloroot W/System.err﹕ at android.os.Looper.loop(Looper.java:136)
helloroot W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5146)
helloroot W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
helloroot W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:515)
helloroot W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:732)
helloroot W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
helloroot W/System.err﹕ at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:132)
helloroot W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)
helloroot W/System.err﹕ Caused by: java.lang.ClassCastException: android.os.BinderProxy cannot be cast to com.android.server.power.PowerManagerService
helloroot W/System.err﹕ at com.android.server.Watchdog.rebootSystem(Watchdog.java:302)
helloroot W/System.err﹕ ... 17 more
Watchdog.java source code
Relevant gradle configuration:
android {
compileSdkVersion 21
buildToolsVersion '21.0.2'
defaultConfig {
minSdkVersion 19
targetSdkVersion 21
回答1:
It seems that you have different SDK implementation on your device checkthis implementation of the method rebootSystem(String resen) on:
https://android.googlesource.com/platform/frameworks/base.git/+/android-4.2.2_r1/services/java/com/android/server/Watchdog.java
/**
* Perform a full reboot of the system.
*/
void rebootSystem(String reason) {
Slog.i(TAG, "Rebooting system because: " + reason);
PowerManagerService pms = (PowerManagerService) ServiceManager.getService("power");
pms.reboot(false, reason, false);
}
and the implementation in the source code you provided on your question:
/**
* Perform a full reboot of the system.
*/
void rebootSystem(String reason) {
Slog.i(TAG, "Rebooting system because: " + reason);
IPowerManager pms = (IPowerManager)ServiceManager.getService(Context.POWER_SERVICE);
try {
pms.reboot(false, reason, false);
} catch (RemoteException ex) {
}
}
that's why you got ClassCastException:
helloroot W/System.err﹕ Caused by: java.lang.ClassCastException: android.os.BinderProxy cannot be cast to com.android.server.power.PowerManagerService
来源:https://stackoverflow.com/questions/27115106/how-to-invoke-an-android-internal-method-with-reflection