code: public static final void setValue(Object obj, String fieldName, 
              Object value) {
          try {
              getField(obj.getClass(), fieldName).set(obj, value);
          } catch (IllegalArgumentException e) {
              throw new RuntimeException(e);
          } catch (IllegalAccessException e) {
              throw new RuntimeException(e);
          }
      }
docs: Sets the field <tt>fieldName</tt> of an object <tt>obj</tt> to a the
  value <tt>value</tt>.
  @param obj The object
  @param fieldName the field name
  @param value The value