code: private Class<?> resolveResultJavaType(Class<?> resultType, String property, Class<?> javaType) {
      if (javaType == null && property != null) {
        try {
          MetaClass metaResultType = MetaClass.forClass(resultType, REFLECTOR_FACTORY);
          javaType = metaResultType.getSetterType(property);
        } catch (Exception ignored) {
          // ignore, following null check statement will deal with the
          // situation
        }
      }
      if (javaType == null) {
        javaType = Object.class;
      }
      return javaType;
    }
docs: copy from mybatis sourceCode
  
  @param resultType
  @param property
  @param javaType
  @return