java - XPosed: Hooking a function overridden in an enum -

say have enum class defined (adapted java documentation)

package com.example.planetexample;  public enum planet {     mercury (3.303e+23, 2.4397e6){         public double surfacegravity() {             return 42;         }     },     venus   (4.869e+24, 6.0518e6);      private final double mass;   // in kilograms     private final double radius; // in meters     planet(double mass, double radius) {         this.mass = mass;         this.radius = radius;     }      // universal gravitational constant  (m3 kg-1 s-2)     public static final double g = 6.67300e-11;      double surfacegravity() {         return g * mass / (radius * radius);     } } 

now, want use xposed hook surfacegravity function has been overriden mercury (and not general 1 defined below). how can access function?

i tried findandhookmethod("com.example.planetexample.planet", lpparam.classloader, "surfacegravity", [etc]), 1 hooks general surfacegravity defined planet class, , not 1 defined mercury. if try com.example.planetexample.planet$mercury or com.example.planetexample.planet.mercury, i'm getting errors xposed function surfacegravity not found.

is there way hook function using xposed?

mercury field of planet enum. since has own implementation, class generated @ compile time it, unfortunately name won't match field's name (e.g., in case com.test.planet$1).

consider following example:

public static void main(string[] args) {      system.out.println("mercury radius: " + planet.mercury.surfacegravity()); // 42     system.out.println("planet class: " + planet.class.getname()); //prints "com.test.planet"      try {         class<?> planet_cls = class.forname("com.test.planet");          system.out.println(planet.class); // com.test.planet         system.out.println(planet.mercury.getclass()); // com.test.planet$1         system.out.println(planet.venus.getclass()); // com.test.planet          for(class c: planet.class.getdeclaredclasses())             system.out.println("name:" + c.getname()); // wont print          for(field c: planet.class.getdeclaredfields())             system.out.println("field name:" + c.getname()); // mercury & venus :)          try {             field mercury_field = planet_cls.getdeclaredfield("mercury");              object o = mercury_field.get(null);              system.out.println("field class name: " + o.getclass()); // com.test.planet$1              try {                 method surfacegravity = o.getclass().getdeclaredmethod("surfacegravity");                  system.out.println("confirm result: " + surfacegravity.invoke(o)); // 42!              } catch (nosuchmethodexception e) {                 e.printstacktrace();             } catch (invocationtargetexception e) {                 e.printstacktrace();             }          } catch (nosuchfieldexception e) {             e.printstacktrace();         } catch (illegalaccessexception e) {             e.printstacktrace();         }     } catch (classnotfoundexception e) {         e.printstacktrace();     } } 

so retrieving field name, can class , methods. note in xposed have hooking api receives method instead of looking name, pass method in example.

the output of code save time:

mercury radius: 42.0 planet class: com.test.planet class com.test.planet class com.test.planet$1 class com.test.planet field name:mercury field name:venus field name:mass field name:radius field name:g field name:$values field class name: class com.test.planet$1 confirm result: 42.0