Merge pull request #1 from Midnight145/Midnight145-patch-1

R::set can now modify final fields on old java versions

Author: MrNavaStar

src/main/java/me/mrnavastar/r/R.java

@@ -6,6 +6,14 @@
 
 public class R {
 
+    private static boolean oldJavaCompat = false;
+    static {
+        try {
+            Field.class.getDeclaredField("modifiers");
+            oldJavaCompat = true;
+        } catch (NoSuchFieldException ignore) {}
+    }
+
     private final Object instance;
     private final Class<?> clazz;
 
@@ -88,7 +96,12 @@ public <T> T get(String name, Class<T> type) {
      */
     public R set(String name, Object value) {
         try {
-            findField(name, clazz).set(instance, value);
+            Field toSet = findField(name, clazz);
+            if (oldJavaCompat) {
+                Field modifiersField = findField("modifiers", toSet.getClass());
+                modifiersField.setInt(toSet, toSet.getModifiers() & ~java.lang.reflect.Modifier.FINAL);
+            }
+            toSet.set(instance, value);
         } catch (NoSuchFieldException | IllegalAccessException e) {
             throw new RuntimeException(e);
         }
@@ -137,4 +150,4 @@ public Class<?>[] generics() {
         }
         return new Class[]{};
     }
-}
+}