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);}
                did you try the method below codepublic static Method findMethodExact(Class<?> clazz, String methodName, Object... parameterTypes) { return findMethodExact(clazz, methodName, getParameterClasses(clazz.getClassLoader(), parameterTypes)); }code
                    – Prasad
                Mar 23 '15 at 13:44
        
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. 
        
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