springboot validation 注解校验

## 引入依赖
```
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>
```

## 手动验证
```
Validator valid = Validation.buildDefualtValidatorFactory().getValidator();
if( !valid.validate(entity).isEmpty()) { 
   // 验证失败
}
```

## 分组校验
用于用户注册时id为空，修改时id不为空的场景分组
权限类
```
public class AuthGroup{
    public interface Insert{}
	
	public interface Update{}
}
```

实体
```
public class User{
    /**
	 * 默认其实是 Default.class的分组
	 */
    @NotNull
    public String userName;
	
	@NotNull(groups = AuthGroup.Insert.class)
	public Interger id;
}
```
调用
```
    @PostMapping("/addUser")
    public Result addUser(@RequestBody @Validated({Default.class, AuthGroup.Insert.class}) User userEntity){
        // TODO 插入
    }
	
	@PostMapping("/update")
    public Result update(@RequestBody @Validated({Default.class, AuthGroup.Update.class}}) User userEntity){
        // TODO 更新
    }
```

https://www.cnblogs.com/super-chao/p/15314566.html

## 嵌套校验，类中有类
https://blog.csdn.net/qq_32352777/article/details/108424932