一.添加依赖
<!-- spring-boot 2.3及以上的版本只需要引入下面的依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-validation</artifactId>
</dependency>
二.在类中使用验证注解
1.创建验证实体类（嵌套使用）
@Data
public class UserDto{
@NotBlank(message = "请输入用户名称")
private String userName;
@NotBlank(message = "请正确输入密码")
@Length(min = 6,max = 18)
private String password;
@Email(message = "请正确输入邮箱")
private String email;
@Valid
@NotEmpty(message = "角色不能为空")
private List<RoleDto> roleDtos;
}
//被嵌套的类
@Data
public class roleDto{
@NotNull(message = "角色ID不能为空")
private Integer roleId;
@NotBlank(message = "请输入角色名称")
private String roleName;
@NotBlank(message = "请输入角色名称")
private String roleCode;
private String desc;
}
2.创建全局异常处理器，对message信息进行处理，并返回给前端
@Component
@Slf4j
public class GlobalValidHandler implements HandlerExceptionResolver {
@Override
public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
ModelAndView modelAndView = new ModelAndView(new MappingJackson2JsonView());
String errorMsg;
if (ex instanceof BindException) {
//对于验证注解在实体类的属性中的异常处理
BindException bex = (BindException) ex;
errorMsg = Objects.requireNonNull(bex.getBindingResult().getFieldError()).getDefaultMessage();
} else if (ex instanceof ConstraintViolationException) {
//对于验证注解直接在方法参数中使用的异常处理
ConstraintViolationException cve = (ConstraintViolationException) ex;
errorMsg = cve.getMessage();
if (errorMsg != null) {
errorMsg = errorMsg.substring(errorMsg.indexOf(": ") 2);
}
} else {
//其他
errorMsg = ex.getMessage();
}
modelAndView.addObject("msg", errorMsg);
modelAndView.addObject("code", HttpServletResponse.SC_BAD_REQUEST);
return modelAndView;
}
}
3.在controller中的使用
@RestController
@RequestMapping("/user")
public class UserController{
@Autowired
private UserService userService;
@PostMapping("/add")
public ApiResult addUser(@Valid @RequsetBody UserDto userDto){
return ApiResult.data(userService.addUser(userDto));
}
}
三.在方法参数中使用验证注解，与@RequsetParam注解同时使用，注意类上使用@Validated
@Validated
@RestController
@RequestMapping("/user")
public class UserController{
@Autowired
private UserSerivce userService;
@GetMapping("/list")
public ApiResult queryUsers(@RequestParam(name="userName", required = false, defaultValue = "")
@NotBlank(message = "请输入用户") String userName,
@RequestParam(name="pageNumber", required = false, defaultValue = 1) Integre pageNumber,
@RequestParam(name="pageSize", required = false, defaultValue = 10) Integre pageSize){
return ApiResult.Data(userService.queryUsers(userName,pageNumber,pageSize));
}
}
ps: 需要在全局变量中对验证注解进行异常处理 GlobalValidHandler
四.自定义验证注解
1.定义验证注解
@Target({ElementType.METHOD, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = MyConstraintValidtor.class)
public @interface MyValidator {
String message() default "校验未通过";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
2.实现验证注解的具体验证逻辑
public class MyConstraintValidator implements ConstraintValidator<MyValidator, Object> {
@Override
public void initialize(MyValidator validator) {
ConstraintValidator.super.initialize(validator);
}
@Override
public boolean isValid(Object value, ConstraintValidatorContext context) {
//具体校验逻辑
//........
//........
//举个例 验证不为空
return !ObjectUtils.isEmpty(value);
}
}
3.使用
@Data
public class UserDto{
@NotNull(message="用户名不能为空")
private String userName;
@MyValidator(message="密码不能为空")
private String password;
}到此这篇关于详解SpringBoot中@NotNull,@NotBlank注解使用的文章就介绍到这了,更多相关SpringBoot注解内容请搜索Devmax以前的文章或继续浏览下面的相关文章希望大家以后多多支持Devmax！