Xposed - How to hook the private static method

问题

Xposed question:

I want to modify some static field in android.os.Build, such as android.os.Build.BOARD, android.os.Build.DEVICE, android.os.Build.DISPLAY.

There are 3 private static methods ( private static String getString(String property), private static String[] getStringList(String property, String separator) , private static long getLong(String property) ) in Build.java.

Then I tried to hook the static method 'getString(String s)' in android.os.Build .

public void handleLoadPackage(final XC_LoadPackage.LoadPackageParam loadPackageParam) throws Throwable {

    XposedBridge.log(loadPackageParam.packageName + " -> load ");

    Class build = XposedHelpers.findClass(Build.class.getName(), loadPackageParam.classLoader);

    XposedHelpers.findAndHookMethod(build, "getString", String.class, new XC_MethodHook() {
        @Override
        protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
            XposedBridge.log("before ->" + param.args[0]);
            super.beforeHookedMethod(param);
        }

        @Override
        protected void afterHookedMethod(MethodHookParam param) throws Throwable {
            XposedBridge.log("after ->" + param.args[0]);
            super.afterHookedMethod(param);
        }
    });}

I try to print the first input argument in the before/after method, when I call android.os.Build.Model. But I'm wrong, it has not been triggered.

How can I hook this private static method in android.os.Build.java

private static String getString(String property) {
    return SystemProperties.get(property, UNKNOWN);}

回答1:

public void initZygote(StartupParam startupParam) throws Throwable {  

    Class clazz = XposedHelpers.findClass(android.os.Build.class.getName(), null);

    Method m = XposedHelpers.findMethodExact(clazz, "getString", String.class);

    m.setAccessible(true);

    XposedBridge.hookMethod(m, new XC_MethodHook() {
        @Override
        protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
            log("call -> " + (String) param.args[0]);
            super.beforeHookedMethod(param);
        }
    });

    String id = (String) m.invoke(null, "ro.build.id");
    log("step 1 try invoke->" + id);
    log("step 2 Call Build.ID ->" + Build.ID);
}

step 1 can raise beforeHookedMethod, but step 2 can not.

回答2:

I also did something like you want recently. Check this: https://github.com/pylerSM/XInstaller/blob/master/src/com/pyler/xinstaller/XInstaller.java#L1146

来源：https://stackoverflow.com/questions/28947591/xposed-how-to-hook-the-private-static-method

标签

java

android

hook

xposed-framework