（九）springboot实战——springboot3下的webflux项目参数验证及其全局参数验证异常处理

前言

在上一节内容中，我们介绍了如何在webflux项目中自定义实现一个全局的异常处理器ErrorWebExceptionHandler，正常情况下其可以处理我们系统的运行时异常，但是无法处理参数验证的异常WebExchangeBindException，所以这里提供另外的全局异常处理方式，通过注解@ExceptionHandler实现参数验证的全局异常处理。

本节内容主要是实现webflux项目集成spring-boot-starter-validation验证框架，完成请求接口参数的后台验证，实现接口请求参数的统一验证处理，返回统一的响应数据格式。

正文

①引入请求参数验证框架spring-boot-starter-validation

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-validation</artifactId>
</dependency>

②创建全局的参数验证异常处理器GlobalExceptionHandler

package com.yundi.atp.exception;import com.yundi.atp.common.ApiResponse;
import com.yundi.atp.common.ErrorCode;
import lombok.extern.slf4j.Slf4j;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.bind.support.WebExchangeBindException;
import reactor.core.publisher.Mono;import java.util.List;@Slf4j
@RestControllerAdvice
public class GlobalExceptionHandler {/*** 参数验证异常** @param ex* @return*/@ExceptionHandler(WebExchangeBindException.class)public Mono<ApiResponse> handleWebExchangeBindException(WebExchangeBindException ex) {log.info("参数验证异常:" + ex);// 处理绑定异常BindingResult result = ex.getBindingResult();List<FieldError> fieldErrors = result.getFieldErrors();return Mono.just(ApiResponse.fail(ErrorCode.WEB_EXCHANGE_BIND_ERROR.getCode(), fieldErrors.get(0).getDefaultMessage()));}/*** 数学计算异常** @param ex* @return*/@ExceptionHandler(ArithmeticException.class)public Mono<ApiResponse> handleArithmeticException(ArithmeticException ex) {log.info("数学计算异常:" + ex);return Mono.just(ApiResponse.fail(ErrorCode.ARITHMETIC_ERROR.getCode(), ErrorCode.ARITHMETIC_ERROR.getMsg()));}/*** 自定义异常** @param ex* @return*/@ExceptionHandler(MyException.class)public Mono<ApiResponse> handleMyException(MyException ex) {log.info("自定义异常：" + ex);return Mono.just(ApiResponse.fail(ex.getCode(), ex.getMessage()));}/*** 兜底异常** @param ex* @return*/@ExceptionHandler(Exception.class)public Mono<ApiResponse> handleMyException(Exception ex) {log.info("系统异常：" + ex);return Mono.just(ApiResponse.fail(ErrorCode.SYSTEM_ERROR.getCode(), ErrorCode.SYSTEM_ERROR.getMsg()));}
}

③ ErrorCode统一定义错误码，方便根据相关错误码处理业务

package com.yundi.atp.common;public enum ErrorCode {SYSTEM_ERROR(10000, "系统错误!"),ARITHMETIC_ERROR(10001, "数学计算异常！"),WEB_EXCHANGE_BIND_ERROR(10002, "参数验证异常！"),;private Integer code;private String msg;ErrorCode(Integer code, String message) {this.code = code;this.msg = message;}public Integer getCode() {return code;}public void setCode(Integer code) {this.code = code;}public String getMsg() {return msg;}public void setMsg(String msg) {this.msg = msg;}
}

④以新增用户数据为例，增加用户数据的验证

package com.yundi.atp.entity;import io.swagger.v3.oas.annotations.media.Schema;
import jakarta.validation.constraints.NotBlank;
import jakarta.validation.constraints.NotNull;
import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.relational.core.mapping.Table;@Schema(name = "User", description = "用户类")
@Table(name = "user")
@Data
public class User {@Id@Schema(name = "id", description = "用户ID")private Integer id;@NotBlank(message = "用户名称不得为空！")@Schema(name = "name", description = "用户名称")private String name;@NotNull(message = "用户年龄不得为空！")@Schema(name = "age", description = "用户年龄")private Integer age;
}

⑤在保存用户请求接口中使用@Valid注解，开启请求参数验证

⑥ 启动webflux应用，使用swagger工具测试保存用户接口，验证参数注解生效，并按照统一响应格式返回了数据

⑦ 验证用户年龄的参数不为空

⑧ swagger需要使用专属webflux的springdoc-openapi-starter-webflux-ui启动器

<!-- https://mvnrepository.com/artifact/org.springdoc/springdoc-openapi-starter-webflux-ui -->
<dependency><groupId>org.springdoc</groupId><artifactId>springdoc-openapi-starter-webflux-ui</artifactId><version>2.3.0</version>
</dependency>