java - 如何使我的循环更加通用？

Question

下面是我的代码。正如您将看到的，有 2 个几乎相同的代码块。唯一不同的是对象的类型。我正在寻找一种使其更通用的方法。拥有一个代码块，只需将类型(Owner、Car)设置为我的方法中的参数。有什么提示吗？我尝试过使用反射，但我始终无法使其动态化，因为我必须循环遍历集合

if(queryResult.get(0) instanceof Owner) {
        classFields = Owner.class.getDeclaredFields();
        data = new Object[queryResult.size()][classFields.length];
        for(Owner owner : (List<Owner>)(Object)queryResult) {
            int rCounter = 0;
            for(Field field : owner.getClass().getDeclaredFields()) {
                field.setAccessible(true);
                try {
                    data[lCounter][rCounter] = field.get(owner);
                } catch (IllegalArgumentException e1) {
                    e1.printStackTrace();
                } catch (IllegalAccessException e1) {
                    e1.printStackTrace();
                }

                rCounter++;
            }
            lCounter++;
        }
    } else if(queryResult.get(0) instanceof Car) {
        classFields = Car.class.getDeclaredFields();
        data = new Object[queryResult.size()][classFields.length];
        for(Car car : (List<Car>)(Object)queryResult) {
            int rCounter = 0;
            for(Field field : car.getClass().getDeclaredFields()) {
                field.setAccessible(true);
                try {
                    data[lCounter][rCounter] = field.get(car);
                } catch (IllegalArgumentException e1) {
                    e1.printStackTrace();
                } catch (IllegalAccessException e1) {
                    e1.printStackTrace();
                }

                rCounter++;
            }
            lCounter++;
        }
    }

Answer 1

您应该能够将整个代码块折叠为:

 Class clazz = queryResult.get(0).getClass();
 classFields = clazz.getDeclaredFields();
 data = new Object[queryResult.size()][classFields.length];
 for(Object result : queryResult) {
     int rCounter = 0;
     for(Field field : clazzFields) {
         field.setAccessible(true);
          try {
              data[lCounter][rCounter] = field.get(result);
          } catch (IllegalArgumentException e1) {
               e1.printStackTrace();
          } catch (IllegalAccessException e1) {
               e1.printStackTrace();
          }
          rCounter++;
      }
      lCounter++;
}

警告:我没有编译并运行它来检查