Springboot学习06-Spring AOP封装接口自定义校验

关键字

　　BindingResult、Spring AOP、自定义注解、自定义异常处理、ConstraintValidator

前言

　　在实际项目中，对接口的传如的参数需要做校验处理，原来都是在接口里面直接进行if判断，虽然简单，但是每个接口都要重复写，显得冗余；并且返回的数据也无法很好的自定义说明校验情况；如下；

    @RequestMapping(value = { "/get/authcode" }, method = {RequestMethod.POST })
    public Object getSignInAuthCode(@RequestBody AuthCodeReq authCodeReq) throws Exception {
    //每个数据都要这样重复写    
    if(StringUtils.isBlank(authCodeReq.getMobile())){
      //返回数据也是固定格式，无法知道究竟是什么数据校验没通过     
     return ResponseMessageEnum.ARGUMENT_EXCEPTION.toString();
    }
     //业务逻辑略
    }

正文

0-封装全局数据校验功能的目的

　　1-避免每个接口重复使用if判断，显得冗余

　　2-可以自定义返回数据，告诉前端什么数据检验失败

1-POST请求业务逻辑(且数据以json格式放在body中传入)

　　1-将数据校验的具体内容放在POJO中，通过注解进行,见源码-01
　　2-当前端URL请求(POST请求，且数据以json格式放在body中传入)，且有数据校验失败时，传参BindException exception会接收校验失败的结果，见源码-02
　　3-使用Spring AOP的前置方法处理数据检验,见源码-03
　　3-1-自定义注解MyValidateAopAnnotation(见源码-04)，用于定位AOP的Pointcut(见源码-03)
　　3-2-AOP前置方法，根据joinPoint获取接口方法BindingResult参数值(见源码-03)
　　3-3-如果bindingResult.hasErrors()为true，则表明数据校验没有通过(见源码-03)，则直接抛出BindException异常()
　　3-4-在GlobalExceptionHandler类中的BindExceptionHandler方法，专门处理BindException异常，返回json数据(见源码-05)

2-GET请求

3-源码分析

//1-POJO
import org.hibernate.validator.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
public class ValidateAuthCodeReq {
    @NotEmpty(message = "手机号不能为空")//message将在接口返回数据中得以体现
    private String mobile;//手机号
    @NotEmpty(message = "验证码不能为空")
    private String code;//验证码

    public String getMobile() {
        return mobile;
    }

    public void setMobile(String mobile) {
        this.mobile = mobile;
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }
}

//2-controller层接口方法
@RestController
@RequestMapping(value="/api/shop/login")
public class ApiShopLoginController extends ApiShopBaseController {


    //2-2-校验并绑定手机号
    @MyValidateAopAnnotation//自定义注解，用户AOP定位方法
    @RequestMapping(value = { "/validate/authcode" }, method = {RequestMethod.POST })
    public Object validateAndBind( @Valid  @RequestBody ValidateAuthCodeReq validateAuthCodeReq,BindingResult bindingResult) throws Exception {
            //BindingResult封装了数据校验结果
            //业务逻辑略
    }
}

//3-AOP方法，统一处理数据校验
@Aspect
@Component
public class ExceptionAspect {
    //根据自定义注解MyValidateAopAnnotation定位方法
    @Pointcut("@annotation(com.hs.web.common.exception.MyValidateAopAnnotation)")
    public void bindPointCut() {
    }

    @Before("bindPointCut()")
    public void before(JoinPoint joinPoint) throws BindException {
        // 接收到请求
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        //获取请求的request
        HttpServletRequest request = attributes.getRequest();
        //获取BindingResult，并进行判断
        Object[] args = joinPoint.getArgs();
        BindingResult bindingResult = (BindingResult)args[args.length-1];
        if(bindingResult.hasErrors()){
            throw  new BindException(bindingResult);
        }
        System.out.println("args[args.length-1]: "+ args[args.length-1]);
        System.out.println("bindingResult" + bindingResult);
    }
}

//4-自定义注解MyValidateAopAnnotation-目的是为了AOP定位
@Target({ METHOD, FIELD, CONSTRUCTOR, PARAMETER })
@Retention(RUNTIME)
@Documented
public @interface MyValidateAopAnnotation {
    
}

//5-全局异常处理类

import com.hs.common.util.json.JsonUtil;
@ControllerAdvice
@ResponseBody
public class GlobalExceptionHandler {
    //数据校验
    @ExceptionHandler(value=BindException.class)
    public String BindExceptionHandler(HttpServletRequest request,BindException exception) throws Exception{
        logger.warn(exception);
        //1-封装异常说明
        List<ObjectError> errorList = exception.getAllErrors();
        StringBuffer sb = new StringBuffer();
        for(ObjectError error : errorList){
            sb.append("参数" + exception.getFieldError().getField() + "异常:" + exception.getFieldError().getDefaultMessage()  + ";");
        }
        //2-封装返回参数
        ExceptionResponseBean detailBean = new ExceptionResponseBean(
                GlobalExceptionEnum.ERROR_DATA_VALIDATION.getCode(),
                GlobalExceptionEnum.ERROR_DATA_VALIDATION.getMsg(),
                sb.toString());
        //3-以Json格式返回数据
        return JsonUtil.toJson(detailBean).toString();
    } 

}

//6-异常情况枚举

import com.hs.common.util.json.JsonUtil;
public enum GlobalExceptionEnum {
    
    OTHER_EXCEPTION(800, "出现异常", "其它异常，待识别", Exception.class),
    
    ERROR_DATA_VALIDATION(801, "数据校验异常", "请求参数数据校验异常", BindException.class),

    ;
    
    private int code;
    private String msg;
    private ExceptionResponseDetailBean data;
    private Class exception;
    private GlobalExceptionEnum(int code, String msg, String data, Class exception) {
        this.code = code;
        this.msg = msg;
        this.data = new ExceptionResponseDetailBean(data);
        this.exception = exception;
    }

    public int getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }

    public ExceptionResponseDetailBean getData() {
        return data;
    }

    public Class getException() {
        return exception;
    }


}


//7-ExceptionResponseBean异常返回POJO
public class ExceptionResponseBean {
    
    private int code;
    private String msg;
    private ExceptionResponseDetailBean data;
    
    public ExceptionResponseBean() {
        super();
    }
    
    public ExceptionResponseBean(int code, String msg, String detail) {
        super();
        this.code = code;
        this.msg = msg;
        this.data = new ExceptionResponseDetailBean(detail);
    }

    public int getCode() {
        return code;
    }
    public void setCode(int code) {
        this.code = code;
    }
    public String getMsg() {
        return msg;
    }
    public void setMsg(String msg) {
        this.msg = msg;
    }
    public ExceptionResponseDetailBean getData() {
        return data;
    }
    public void setData(ExceptionResponseDetailBean data) {
        this.data = data;
    }    

}

//8-ExceptionResponseDetailBean异常返回明细POJO

public class ExceptionResponseDetailBean {
    
    private String detail;

    public ExceptionResponseDetailBean() {
        super();
    }

    public ExceptionResponseDetailBean(String detail) {
        super();
        this.detail = detail;
    }

    public String getDetail() {
        return detail;
    }

    public void setDetail(String detail) {
        this.detail = detail;
    }        
}

4-应用示例

5-进一步优化校验

5-1-优点和问题

上面的数据校验已经进行分装，实现了和接口业务低耦合要求，并且可以自定义结果；但有一个问题：对于每一个POJO要校验的参数，都要重复指定message值，
示例：@NotEmpty(message = "手机号不能为空") ；如果多个POJO对手机号验证，又会出现冗余情况

5-2-优化思路

自定义校验注解，对相同或类似的参数使用相同的自定义注解(见源码-01)
自定义注解需要，自定义一个注解类(见源码-03)和一个ConstraintValidator实现类(见源码-03)

5-3-源码分析

//1-POJO
package com.hs.api.shopapp.entity.commom;

import com.hs.web.common.annotation.validation.MobileFormat;

public class AuthCodeReq {

    @MobileFormat//使用自定义校验注解
    private String mobile;//手机号

    public String getMobile() {
        return mobile;
    }

    public void setMobile(String mobile) {
        this.mobile = mobile;
    }
}

//2-自定义注解MobileFormat
@Documented
@Target({ElementType.METHOD, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = MobileConstraintValidator.class)
public @interface MobileFormat {
    String message() default "手机号格式不正确";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

    @Target({ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.PARAMETER})
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    public @interface List {
        NotBlank[] value();
    }
}


//3-重写ConstraintValidator接口，自定义校验规则
public class MobileConstraintValidator implements ConstraintValidator<MobileFormat,String>{

    @Override
    public void initialize(MobileFormat constraintAnnotation) {
    }

    //在当前方法指定校验规则
    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        if(StringUtil.isBlank(value)){
            return false;
        }
        return true;
    }
}



//4-测试接口
@RestController
@RequestMapping(value="/api/shop/login")
public class ApiShopLoginController extends ApiShopBaseController {

    @MyValidateAopAnnotation
    @RequestMapping(value = { "/get/authcode" }, method = {RequestMethod.POST })
    public Object getSignInAuthCode(@Valid @RequestBody AuthCodeReq authCodeReq,BindingResult bindingResult) throws Exception {
        //业务逻辑略
    }


}

5-4-应用示例

6-备注

6-1-@NotEmpty、@NotNull、@NotBlank 的区别

@NotEmpty 用在集合上面(不能注释枚举)
@NotBlank用在String上面
@NotNull用在所有类型上面

参考文献

1-https://blog.csdn.net/ranshenyi/article/details/79548188
2-https://www.cnblogs.com/NeverCtrl-C/p/8185576.html