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;
- }
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