Spring boot实现基于注解的aop面向切面编程

背景

从最开始使用Spring，AOP和IOC的理念就深入我心。正好，我需要写一个基于注解的AOP，被这个注解修饰的参数和属性，就会被拿到参数并校验参数。

一，引入依赖

当前spring boot版本为2.7.18，我引入的aspectjweaver版本为1.9.5。

     <dependency><groupId>org.aspectj</groupId><artifactId>aspectjweaver</artifactId><version>1.9.5</version></dependency>

二，写注解

这个注解用来修饰方法，相当于一个切点，加上这个注解，这个方法就被被aop执行。

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface ParamInterceptor {boolean checkParam() default true;
}

在这里插入图片描述
这个注解是用来修饰参数和属性的。被修饰的参数和属性在aop中会通过反射取出数据并判断

@Target({ElementType.PARAMETER, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
public @interface VerifyParam {int min() default -1;int max() default -1;boolean required() default false;VerifyRegexEnum regex() default VerifyRegexEnum.NO;
}

这个是用到的VerifyRegexEnum 枚举类

@AllArgsConstructor
@Getter
public enum VerifyRegexEnum {NO("", "不校验"),IP("^((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3})$", "ip地址"),POSITIVE_INTEGER("^\\d+$", "正整数"),NUMBER_LETTER_UNDER_LINE("\\w+$", "数字字母下划线"),PHONE("^1[3-9]\\d{9}$", "手机号"),EMAIL("^\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*$", "邮箱"),ID_CARD("^\\d{17}(\\d|x|X)$", "身份证"),PASSWORD("^[a-zA-Z0-9]{6,20}$", "密码"),MONEY("^\\d+(\\.\\d+)?$", "金额"),;private String regex;private String desc;public static boolean isMatch(String regex, String str) {return str.matches(regex);}}

三，编写切面aspect

该切面类就实现了，对参数和属性的校验。

@Aspect
@Component
@Slf4j
public class CdesAspect {@Before("@annotation(com.cdes.annotation.ParamInterceptor)")public void before(JoinPoint point) {Object[] args = point.getArgs();Method method = ((MethodSignature) point.getSignature()).getMethod();log.info("参数校验,方法名：{}",method.getName());ParamInterceptor paramInterceptor = method.getAnnotation(ParamInterceptor.class);if (paramInterceptor == null ) {return;}if(!paramInterceptor.checkParam()){return;}try{checkParam(method,args);}catch (Exception e){throw new BizException("400",e.getMessage());}}private void checkParam(Method method, Object[] args) throws IllegalAccessException {Parameter[] parameters = method.getParameters();for (int i = 0; i < parameters.length; i++) {Parameter parameter = parameters[i];Object paramValue = args[i];VerifyParam paramAnnotation = parameter.getAnnotation(VerifyParam.class);//取方法参数上的注解,如果有，则校验参数,如果没有，取该参数的属性，看是否有该注解if (paramAnnotation != null) {if(paramAnnotation.required() && paramValue == null){throw new BizException( "400",parameter.getName()+":参数不能为空");}if(paramAnnotation.max() != -1){if (paramValue.toString().length() > paramAnnotation.max()) {throw new BizException( "400",parameter.getName()+":参数长度不能超过"+paramAnnotation.max());}}if(paramAnnotation.min() != -1){if (paramValue.toString().length() < paramAnnotation.min()) {throw new BizException( "400",parameter.getName()+":参数长度不能小于"+paramAnnotation.min());}}if(paramAnnotation.regex() != null){if(!VerifyRegexEnum.isMatch(paramAnnotation.regex().getRegex(),paramValue.toString())){throw new BizException( "400",parameter.getName()+":参数不符合正则表达式");}}}else{//取属性上的注解，看是否需要校验Field[] fields = parameter.getClass().getDeclaredFields();if(fields == null || fields.length == 0){continue;}for (Field field : fields) {field.setAccessible(true);VerifyParam ann = field.getAnnotation(VerifyParam.class);if(ann == null){continue;}Object filedValue = field.get(paramValue);if(ann.required() && filedValue == null){throw new BizException( "400",field.getName()+":参数不能为空");}if(ann.max() != -1){if (filedValue.toString().length() > ann.max()) {throw new BizException( "400",field.getName()+":参数长度不能超过"+ann.max());}}if(ann.min() != -1){if (filedValue.toString().length() < ann.min()) {throw new BizException( "400",field.getName()+":参数长度不能小于"+ann.min());}}if(ann.regex() != null){if(!VerifyRegexEnum.isMatch(ann.regex().getRegex(),filedValue.toString())){throw new BizException( "400",field.getName()+":参数不符合正则表达式");}}}}}}
}

四，使用

controller中的login方法加上了ParamInterceptor注解，然后这个方法的入参LoginDTO中的属性加上了VerifyParam注解
在这里插入图片描述

@Data
@AllArgsConstructor
@NoArgsConstructor
public class LoginDTO {@VerifyParam(regex = VerifyRegexEnum.PHONE)private String phone;@VerifyParam(regex = VerifyRegexEnum.PASSWORD)private String password;@VerifyParam(required = true)private String verifyCode;@VerifyParam(required = true)private String codeId;
}