java 利用反射使list根据任意对象某个属性排序

public class CommonTest {
    
    

    public static void main(String[] args) {
    
    
        User one = new User();
        one.setAge(1);
        User two = new User();
        two.setAge(3);
        User three = new User();
        three.setAge(2);

        List<User> ulist = new ArrayList();
        ulist.add(one);
        ulist.add(two);
        ulist.add(three);

        CommonTest.sort(ulist,"Age");

    }

    // 倒排
    public static void sort(List list, String field){
    
    
        if (list == null || list.size() == 0) return;
        list.sort((o1, o2) -> {
    
    
            try {
    
    
                Method getter1 = o1.getClass().getDeclaredMethod("get" + field);
                Object val1 = getter1.invoke(o1);
                Method getter2 = o2.getClass().getDeclaredMethod("get" + field);
                Object val2 = getter2.invoke(o2);

                if (val1 == null) {
    
    
                    if (val2 == null) {
    
    
                        return 0;
                    } else {
    
    
                        return -1;
                    }
                }
                if (val2 == null) return -1;
                if (val1 instanceof BigDecimal && val2 instanceof BigDecimal) {
    
    
                    return -((BigDecimal) val1).compareTo((BigDecimal) val2);
                }
                return 1;

            } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
    
    
                e.printStackTrace();
            }
            return 1;
        });
    }
}

class User{
    
    
    private int age;

    public int getAge() {
    
    
        return age;
    }

    public void setAge(int age) {
    
    
        this.age = age;
    }
}