SpringBoot注解校验请求参数

梦里梦外; 2022-05-08 00:14 357阅读 0赞

## 常规校验 ##

@RequestMapping( value = "test", method = RequestMethod.POST) public FrogTest test(@RequestBody FrogTest bean) { if (bean.getName() == null) { throw new MyException("A02", "名称不能为空"); } if (bean.getSize() > 100) { throw new MyException("A03", "size值超过允许最大值"); } return bean; }

通常通过以上方式，对前端请求参数进行校验，如果请求bean(FrogTest)中需要校验的属性太多时，对每个参数写一个对应的if判断，代码可读性很差，所以可以在请求对象属性加上注解来校验其合法性。

## 属性加校验注解 ##

public class FrogTest implements Serializable { private static final long serialVersionUID = 1L; @TableId(value = "id", type = IdType.AUTO) private Integer id; @NotEmpty(message = "名称项不能为空") private String name; private String describ; private LocalDateTime date; @NotEmpty(message = "状态标识项不能为空") @Pattern(regexp = "[012]", message = "无效的状态标志") private String state; @SizeValidator(maxSize = 100.1, message = "值太大") private Double size; ... 省略getter和setter }

其中@NotEmpty和@Pattern是javax.validation.constraints包中注解，前者表示不为空，后者表示为特定格式，现在表示只能为0、1、2。@SizeValidator是自定义注解，用来校验值得大小（可以用@Size），如下：

@Target(ElementType.FIELD) @Retention(RetentionPolicy.RUNTIME) @Documented @Constraint( validatedBy = { SizeValidatorImpl.class} ) public @interface SizeValidator { double maxSize() default 10000.0; String message() default "值得大小不合法"; Class<?>[] groups() default { }; Class<? extends Payload>[] payload() default { }; }

约束实现类：

public class SizeValidatorImpl implements ConstraintValidator<SizeValidator, Double> { private double maxSize; @Override public void initialize(SizeValidator constraintAnnotation) { maxSize = constraintAnnotation.maxSize(); } @Override public boolean isValid(Double value, ConstraintValidatorContext context) { if (value > 0 && value < maxSize) { return true; } return false; } }

## 修改Controller ##

请求参数增加@Valid注解

@RequestMapping( value = "test", method = RequestMethod.POST) public FrogTest test(@RequestBody @Valid FrogTest bean) { /*不需要通过if判断校验 if (bean.getName() == null) { throw new MyException("A02", "名称不能为空"); } if (bean.getSize() > 100) { throw new MyException("A03", "size值超过允许最大值"); }*/ return bean; }

## 异常拦截与返回 ##

在[SpringBoot项目通用返回值与全局异常处理][SpringBoot]的基础上修改

@RestControllerAdvice public class MyExceptionHandler { private Logger logger = LoggerFactory.getLogger(getClass()); @ExceptionHandler(Exception.class) public Object handleException(Exception e, HttpServletRequest request, HttpServletResponse response){ logger.error("请求：{}发生异常：{}", request.getRequestURI(), e); Result result = new Result(); result.setSuccess(false); if (e instanceof MyException) { result.setErrorCode(((MyException) e).getErrorCode()); result.setErrorMsg(((MyException) e).getErrorMsg()); } else { result.setErrorCode(MyExceptionEnum.SYSTEM_ERROR.getCode()); result.setErrorMsg(MyExceptionEnum.SYSTEM_ERROR.getMsg()); } return result; } /** * 自定义注解异常拦截 */ @ExceptionHandler({ BindException.class, ConstraintViolationException.class, MethodArgumentNotValidException.class}) public Object handleMethodArgumentNotValidException(Exception e, HttpServletRequest request) { logger.error("请求：{}发生异常：{}", request.getRequestURI(), e); // 错误信息 StringBuilder sb = new StringBuilder("参数校验失败："); // 错误信息map Map<String, String> error = new HashMap<>(); String msg = ""; if (!(e instanceof BindException) && !(e instanceof MethodArgumentNotValidException)) { for (ConstraintViolation cv: ((ConstraintViolationException)e).getConstraintViolations()) { msg = cv.getMessage(); sb.append(msg).append("；"); Iterator<Path.Node> it = cv.getPropertyPath().iterator(); Path.Node last = null; while (it.hasNext()) { last = (Path.Node)it.next(); } /*for(last = null; it.hasNext(); last = (Path.Node)it.next()) { }*/ error.put(last != null ? last.getName() : "", msg); } } else { List<ObjectError> allErrors = null; if (e instanceof BindException) { allErrors = ((BindException)e).getAllErrors(); } else { allErrors = ((MethodArgumentNotValidException)e).getBindingResult().getAllErrors(); } // 拼接错误信息 for (ObjectError oe : allErrors) { msg = oe.getDefaultMessage(); sb.append(msg).append("；"); if (oe instanceof FieldError) { error.put(((FieldError)oe).getField(), msg); } else { error.put(oe.getObjectName(), msg); } } } Result<Map> result = new Result<>(error); result.setSuccess(false); result.setErrorCode(MyExceptionEnum.REQUESTPARAM_ERROR.getCode()); result.setErrorMsg(MyExceptionEnum.REQUESTPARAM_ERROR.getMsg() + sb.toString()); return result; } }

## 测试 ##

![在这里插入图片描述][70]

![在这里插入图片描述][70 1]  
提示了错误信息，以及每个属性的校验失败信息，可以根据需要调整是否显示或记录到日志中。

[SpringBoot]: https://blog.csdn.net/litte_frog/article/details/82700310
[70]: /images/20220508/24f35488c9244e7a8026cf5be51eca34.png
[70 1]: /images/20220508/8f30460d3a20413795fccfbf2752c9fc.png