Spring Boot 还在用 if 校验参数？
SpringForAll
Posted on
简单使用
引入依赖
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>6.0.1.Final</version>
</dependency>
POST、PUT请求，使用requestBody传递参数； GET请求，使用requestParam/PathVariable传递参数。
requestBody参数校验
@Data
public class UserDTO {
private Long userId;
@NotNull
@Length(min = 2, max = 10)
private String userName;
@NotNull
@Length(min = 6, max = 20)
private String account;
@NotNull
@Length(min = 6, max = 20)
private String password;
}
@PostMapping("/save")
public Result saveUser(@RequestBody @Validated UserDTO userDTO) {
// 校验通过，才会执行业务逻辑处理
return Result.ok();
}
requestParam/PathVariable参数校验
@RequestMapping("/api/user")
@RestController
@Validated
public class UserController {
// 路径变量
@GetMapping("{userId}")
public Result detail(@PathVariable("userId") @Min(10000000000000000L) Long userId) {
// 校验通过，才会执行业务逻辑处理
UserDTO userDTO = new UserDTO();
userDTO.setUserId(userId);
userDTO.setAccount("11111111111111111");
userDTO.setUserName("xixi");
userDTO.setAccount("11111111111111111");
return Result.ok(userDTO);
}
// 查询参数
@GetMapping("getByAccount")
public Result getByAccount(@Length(min = 6, max = 20) @NotNull String account) {
// 校验通过，才会执行业务逻辑处理
UserDTO userDTO = new UserDTO();
userDTO.setUserId(10000000000000003L);
userDTO.setAccount(account);
userDTO.setUserName("xixi");
userDTO.setAccount("11111111111111111");
return Result.ok(userDTO);
}
}
统一异常处理
@RestControllerAdvice
public class CommonExceptionHandler {
@ExceptionHandler({MethodArgumentNotValidException.class})
@ResponseStatus(HttpStatus.OK)
@ResponseBody
public Result handleMethodArgumentNotValidException(MethodArgumentNotValidException ex) {
BindingResult bindingResult = ex.getBindingResult();
StringBuilder sb = new StringBuilder("校验失败:");
for (FieldError fieldError : bindingResult.getFieldErrors()) {
sb.append(fieldError.getField()).append("：").append(fieldError.getDefaultMessage()).append(", ");
}
String msg = sb.toString();
return Result.fail(BusinessCode.参数校验失败, msg);
}
@ExceptionHandler({ConstraintViolationException.class})
@ResponseStatus(HttpStatus.OK)
@ResponseBody
public Result handleConstraintViolationException(ConstraintViolationException ex) {
return Result.fail(BusinessCode.参数校验失败, ex.getMessage());
}
}
进阶使用
分组校验
@Data
public class UserDTO {
@Min(value = 10000000000000000L, groups = Update.class)
private Long userId;
@NotNull(groups = {Save.class, Update.class})
@Length(min = 2, max = 10, groups = {Save.class, Update.class})
private String userName;
@NotNull(groups = {Save.class, Update.class})
@Length(min = 6, max = 20, groups = {Save.class, Update.class})
private String account;
@NotNull(groups = {Save.class, Update.class})
@Length(min = 6, max = 20, groups = {Save.class, Update.class})
private String password;
/**
* 保存的时候校验分组
*/
public interface Save {
}
/**
* 更新的时候校验分组
*/
public interface Update {
}
}
@PostMapping("/save")
public Result saveUser(@RequestBody @Validated(UserDTO.Save.class) UserDTO userDTO) {
// 校验通过，才会执行业务逻辑处理
return Result.ok();
}
@PostMapping("/update")
public Result updateUser(@RequestBody @Validated(UserDTO.Update.class) UserDTO userDTO) {
// 校验通过，才会执行业务逻辑处理
return Result.ok();
}
嵌套校验
@Data
public class UserDTO {
@Min(value = 10000000000000000L, groups = Update.class)
private Long userId;
@NotNull(groups = {Save.class, Update.class})
@Length(min = 2, max = 10, groups = {Save.class, Update.class})
private String userName;
@NotNull(groups = {Save.class, Update.class})
@Length(min = 6, max = 20, groups = {Save.class, Update.class})
private String account;
@NotNull(groups = {Save.class, Update.class})
@Length(min = 6, max = 20, groups = {Save.class, Update.class})
private String password;
@NotNull(groups = {Save.class, Update.class})
@Valid
private Job job;
@Data
public static class Job {
@Min(value = 1, groups = Update.class)
private Long jobId;
@NotNull(groups = {Save.class, Update.class})
@Length(min = 2, max = 10, groups = {Save.class, Update.class})
private String jobName;
@NotNull(groups = {Save.class, Update.class})
@Length(min = 2, max = 10, groups = {Save.class, Update.class})
private String position;
}
/**
* 保存的时候校验分组
*/
public interface Save {
}
/**
* 更新的时候校验分组
*/
public interface Update {
}
}
List<Job>字段会对这个list里面的每一个Job对象都进行校验集合校验
public class ValidationList<E> implements List<E> {
@Delegate // @Delegate是lombok注解
@Valid // 一定要加@Valid注解
public List<E> list = new ArrayList<>();
// 一定要记得重写toString方法
@Override
public String toString() {
return list.toString();
}
}
@PostMapping("/saveList")
public Result saveList(@RequestBody @Validated(UserDTO.Save.class) ValidationList<UserDTO> userList) {
// 校验通过，才会执行业务逻辑处理
return Result.ok();
}
自定义校验
@Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER})
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = {EncryptIdValidator.class})
public @interface EncryptId {
// 默认错误消息
String message() default "加密id格式错误";
// 分组
Class<?>[] groups() default {};
// 负载
Class<? extends Payload>[] payload() default {};
}
public class EncryptIdValidator implements ConstraintValidator<EncryptId, String> {
private static final Pattern PATTERN = Pattern.compile("^[a-f\\d]{32,256}$");
@Override
public boolean isValid(String value, ConstraintValidatorContext context) {
// 不为null才进行校验
if (value != null) {
Matcher matcher = PATTERN.matcher(value);
return matcher.find();
}
return true;
}
}
编程式校验
@Autowired
private javax.validation.Validator globalValidator;
// 编程式校验
@PostMapping("/saveWithCodingValidate")
public Result saveWithCodingValidate(@RequestBody UserDTO userDTO) {
Set<ConstraintViolation<UserDTO>> validate = globalValidator.validate(userDTO, UserDTO.Save.class);
// 如果校验通过，validate为空；否则，validate包含未校验通过项
if (validate.isEmpty()) {
// 校验通过，才会执行业务逻辑处理
} else {
for (ConstraintViolation<UserDTO> userDTOConstraintViolation : validate) {
// 校验失败，做其它逻辑
System.out.println(userDTOConstraintViolation);
}
}
return Result.ok();
}
快速失败(Fail Fast)
@Bean
public Validator validator() {
ValidatorFactory validatorFactory = Validation.byProvider(HibernateValidator.class)
.configure()
// 快速失败模式
.failFast(true)
.buildValidatorFactory();
return validatorFactory.getValidator();
}
@Valid和@Validated区别
实现原理
requestBody参数校验实现原理
public class RequestResponseBodyMethodProcessor extends AbstractMessageConverterMethodProcessor {
@Override
public Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer,
NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception {
parameter = parameter.nestedIfOptional();
//将请求数据封装到DTO对象中
Object arg = readWithMessageConverters(webRequest, parameter, parameter.getNestedGenericParameterType());
String name = Conventions.getVariableNameForParameter(parameter);
if (binderFactory != null) {
WebDataBinder binder = binderFactory.createBinder(webRequest, arg, name);
if (arg != null) {
// 执行数据校验
validateIfApplicable(binder, parameter);
if (binder.getBindingResult().hasErrors() && isBindExceptionRequired(binder, parameter)) {
throw new MethodArgumentNotValidException(parameter, binder.getBindingResult());
}
}
if (mavContainer != null) {
mavContainer.addAttribute(BindingResult.MODEL_KEY_PREFIX + name, binder.getBindingResult());
}
}
return adaptArgumentIfNecessary(arg, parameter);
}
}
protected void validateIfApplicable(WebDataBinder binder, MethodParameter parameter) {
// 获取参数注解，比如@RequestBody、@Valid、@Validated
Annotation[] annotations = parameter.getParameterAnnotations();
for (Annotation ann : annotations) {
// 先尝试获取@Validated注解
Validated validatedAnn = AnnotationUtils.getAnnotation(ann, Validated.class);
//如果直接标注了@Validated，那么直接开启校验。
//如果没有，那么判断参数前是否有Valid起头的注解。
if (validatedAnn != null || ann.annotationType().getSimpleName().startsWith("Valid")) {
Object hints = (validatedAnn != null ? validatedAnn.value() : AnnotationUtils.getValue(ann));
Object[] validationHints = (hints instanceof Object[] ? (Object[]) hints : new Object[] {hints});
//执行校验
binder.validate(validationHints);
break;
}
}
}
@Override
public void validate(Object target, Errors errors, Object... validationHints) {
if (this.targetValidator != null) {
processConstraintViolations(
//此处调用Hibernate Validator执行真正的校验
this.targetValidator.validate(target, asValidationGroups(validationHints)), errors);
}
}
方法级别的参数校验实现原理
public class MethodValidationPostProcessor extends AbstractBeanFactoryAwareAdvisingPostProcessorimplements InitializingBean {
@Override
public void afterPropertiesSet() {
//为所有`@Validated`标注的Bean创建切面
Pointcut pointcut = new AnnotationMatchingPointcut(this.validatedAnnotationType, true);
//创建Advisor进行增强
this.advisor = new DefaultPointcutAdvisor(pointcut, createMethodValidationAdvice(this.validator));
}
//创建Advice，本质就是一个方法拦截器
protected Advice createMethodValidationAdvice(@Nullable Validator validator) {
return (validator != null ? new MethodValidationInterceptor(validator) : new MethodValidationInterceptor());
}
}
public class MethodValidationInterceptor implements MethodInterceptor {
@Override
public Object invoke(MethodInvocation invocation) throws Throwable {
//无需增强的方法，直接跳过
if (isFactoryBeanMetadataMethod(invocation.getMethod())) {
return invocation.proceed();
}
//获取分组信息
Class<?>[] groups = determineValidationGroups(invocation);
ExecutableValidator execVal = this.validator.forExecutables();
Method methodToValidate = invocation.getMethod();
Set<ConstraintViolation<Object>> result;
try {
//方法入参校验，最终还是委托给Hibernate Validator来校验
result = execVal.validateParameters(
invocation.getThis(), methodToValidate, invocation.getArguments(), groups);
}
catch (IllegalArgumentException ex) {
...
}
//有异常直接抛出
if (!result.isEmpty()) {
throw new ConstraintViolationException(result);
}
//真正的方法调用
Object returnValue = invocation.proceed();
//对返回值做校验，最终还是委托给Hibernate Validator来校验
result = execVal.validateReturnValue(invocation.getThis(), methodToValidate, returnValue, groups);
//有异常直接抛出
if (!result.isEmpty()) {
throw new ConstraintViolationException(result);
}
return returnValue;
}
}
END
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