多字段联合校验

内部类级联校验

1. Person 对象 和 Child 对象，如下代码：

   @Getter
   @Setter
   @ToString
   public class Person {
       @NotNull
       private String name;
       @NotNull
       @Range(min = 10, max = 40)
       private Integer age;
       @NotNull
       @Size(min = 3, max = 5)
       private List<String> hobbies;
       // 级联校验
       @Valid
       @NotNull
       private Child child;
       public static class Child {
           @NotNull
           private String name;
       }
       public static void main(String[] args)  {
           Person person = new Person();
           person.setName("kp");
           person.setAge(5);
           person.setHobbies(Arrays.asList("足球","篮球"));
           person.setChild(new Child());
   
           Set<ConstraintViolation<Person>> result = Validation.buildDefaultValidatorFactory().getValidator().validate(person);
   
           // 对结果进行遍历输出
           result.stream().map(v -> v.getPropertyPath() + " "
                   + v.getMessage() + ": " + v.getInvalidValue()).forEach(System.out::println);
       }
   }

2. 输出结果：

   hobbies 个数必须在3和5之间: [足球, 篮球]
   age 需要在10和40之间: 5
   child.name 不能为null: null

分组条件校验

1. Person2 类，当年龄满足分组条件的，那么会校验 hobbies 的集合大小，例如：WhenAge20And30Group组，那么年龄在20~30岁，会校验集合大小是否满足。

   @GroupSequenceProvider(PersonGroupSequenceProvider.class)
   @Getter
   @Setter
   @ToString
   public class Person2 {
       @NotNull
       private String name;
       @NotNull
       @Range(min = 10, max = 40)
       private Integer age;
   
       @NotNull(groups = {WhenAge20And30Group.class, WhenAge30And40Group.class})
       @Size(min = 1, max = 2, message = "hobbies 长度 1~2", groups = WhenAge20And30Group.class)
       @Size(min = 3, max = 5, message = "hobbies 长度 3~5", groups = WhenAge30And40Group.class)
       private List<String> hobbies;
   
       /**
        * 定义专属的业务逻辑分组
        */
       public interface WhenAge20And30Group {
       }
       public interface WhenAge30And40Group {
       }
   
       public static void main(String[] args) {
           Person2 person2 = new Person2();
           person2.setName("kp");
           person2.setAge(35);
           person2.setHobbies(Arrays.asList("足球","羽毛球"));
           Set<ConstraintViolation<Person2>> result2 = Validation.buildDefaultValidatorFactory().getValidator().validate(person2);
   
           // 对结果进行遍历输出
           result2.stream().map(v -> v.getPropertyPath() + " "
                   + v.getMessage() + ": " + v.getInvalidValue()).forEach(System.out::println);
       }
   }

2. 实现 DefaultGroupSequenceProvider 接口，getValidationGroups 参数可以使用Object + 反射让它变得更为通用，但本着职责单一原则，不建议这么去做。

   public class PersonGroupSequenceProvider implements DefaultGroupSequenceProvider<Person2> {
   
       @Override
       public List<Class<?>> getValidationGroups(Person2 person) {
           List<Class<?>> defaultGroupSequence = new ArrayList<>();
           // 这一步不能省,否则 Default 分组都不会执行了，会抛错的
           defaultGroupSequence.add(Person2.class);
   
           // 这块判空请务必要做
           if (person != null) {
               Integer age = person.getAge();
               System.err.println("年龄为：" + age + "，执行对应校验逻辑");
               if (age >= 20 && age < 30) {
                   defaultGroupSequence.add(Person2.WhenAge20And30Group.class);
               } else if (age >= 30 && age < 40) {
                   defaultGroupSequence.add(Person2.WhenAge30And40Group.class);
               }
           }
           return defaultGroupSequence;
       }
   }

   校验顺序

3. 例如校验 A->B->C，先校验A，如果 A 满足条件，则校验 B，B 满足条件，则校验 C，如下代码：

   @Data
   public class User {
       @NotEmpty(message = "firstname may be empty")
       private String firstname;
       @NotEmpty(message = "middlename may be empty", groups = Default.class)
       private String middlename;
       @NotEmpty(message = "lastname may be empty", groups = GroupA.class)
       private String lastname;
       @NotEmpty(message = "country may be empty", groups = GroupB.class)
       private String country;
       public interface GroupA {
       }
       public interface GroupB {
       }
       // 组序列
       @GroupSequence({Default.class, GroupA.class, GroupB.class})
       public interface Group {
       }
       public static void main(String[] args) {
           User user = new User();
           user.setMiddlename("hello");
           user.setFirstname("hello");
           // 此处指定了校验组是：User.Group.class
           Set<ConstraintViolation<User>> result = Validation.buildDefaultValidatorFactory().getValidator().validate(user, User.Group.class);
   
           // 对结果进行遍历输出
           result.stream().map(v -> v.getPropertyPath() + " " + v.getMessage() + ": " + v.getInvalidValue()).forEach(System.out::println);
       }
   }