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-POJOimport 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@Componentpublic 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)@Documentedpublic @interface MyValidateAopAnnotation { }//5-全局异常处理类import com.hs.common.util.json.JsonUtil;@ControllerAdvice@ResponseBodypublic 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 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POJOpublic 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POJOpublic 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-POJOpackage 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 [] 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 { @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
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