Controller層方法參數校驗和全局異常捕獲

在表單提交時，controller都要驗證從前端接受的參數，假如每個參數都手動判斷會比較麻煩，可以采用驗證框架來簡化對參數的驗證

1 導入依賴

        <!--JSR303參數校驗開始-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>
        <!--JSR303參數校驗結束-->

 2 controller層方法形參添加Valid注解

    @RequestMapping("/do_login")
    @ResponseBody
    public Result<String> doLogin(HttpServletResponse response, @Valid LoginVo loginVo) {
        log.info(loginVo.toString());
        //登錄
        String token = userService.login(response, loginVo);
        return Result.success(token);
    }

對請求參數的封裝pojo

這里的NotNull 是框架自帶的注解，IsMobile是自定義注解

public class LoginVo {

    @NotNull
    @IsMobile
    private String mobile;

    @NotNull
    @Length(min=6,max=16,message = "密碼長度錯誤")
    private String password;

    public String getMobile() {
        return mobile;
    }
    public void setMobile(String mobile) {
        this.mobile = mobile;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "LoginVo [mobile=" + mobile + ", password=" + password + "]";
    }
}

安裝下面的方式自定義注解

@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = {IsMobileValidator.class })
public @interface  IsMobile {
    
    boolean required() default true;
    
    String message() default "手機號碼格式錯誤";

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

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

public class IsMobileValidator implements ConstraintValidator<IsMobile, String> {

    private boolean required = false;
    
    public void initialize(IsMobile constraintAnnotation) {
        required = constraintAnnotation.required();
    }

    public boolean isValid(String value, ConstraintValidatorContext context) {
        if(required) {
            return ValidatorUtil.isMobile(value);
        }else {
            if(StringUtils.isEmpty(value)) {
                return true;
            }else {
                return ValidatorUtil.isMobile(value);
            }
        }
    }

}

3 全局異常捕獲

public class GlobalException extends RuntimeException{

    private static final long serialVersionUID = 1L;
    
    private CodeMsg cm;
    
    public GlobalException(CodeMsg cm) {
        super(cm.toString());
        this.cm = cm;
    }

    public CodeMsg getCm() {
        return cm;
    }

}

@ControllerAdvice
@ResponseBody
public class GlobalExceptionHandler {
    @ExceptionHandler(value=Exception.class)
    public Result<String> exceptionHandler(HttpServletRequest request, Exception e){
        e.printStackTrace();
        if(e instanceof GlobalException) {
            GlobalException ex = (GlobalException)e;
            return Result.error(ex.getCm());
        }else if(e instanceof BindException) {
            BindException ex = (BindException)e;
            List<ObjectError> errors = ex.getAllErrors();
            ObjectError error = errors.get(0);
            String msg = error.getDefaultMessage();
            return Result.error(CodeMsg.BIND_ERROR.fillArgs(msg));
        }else {
            return Result.error(CodeMsg.SERVER_ERROR);
        }
    }
}

4 service層方法

    public String login(HttpServletResponse response, LoginVo loginVo) {
        if(loginVo == null) {
            throw new GlobalException(CodeMsg.SERVER_ERROR);
        }
        String mobile = loginVo.getMobile();
        String formPass = loginVo.getPassword();
        //判斷手機號是否存在
        MiaoshaUser user = getById(Long.parseLong(mobile));
        if(user == null) {
            throw new GlobalException(CodeMsg.MOBILE_NOT_EXIST);
        }
        //驗證密碼
        String dbPass = user.getPassword();
        String saltDB = user.getSalt();
        String calcPass = MD5Util.formPassToDBPass(formPass, saltDB);
        if(!calcPass.equals(dbPass)) {
            throw new GlobalException(CodeMsg.PASSWORD_ERROR);
        }
        //生成cookie
        String token    = UUIDUtil.uuid();
        addCookie(response, token, user);
        return token;
    }

5 返回給前端的json

public class Result<T> {
    
    private int code;
    private String msg;
    private T data;
    
    /**
     *  成功時候的調用
     * */
    public static  <T> Result<T> success(T data){
        return new Result<T>(data);
    }
    
    /**
     *  失敗時候的調用
     * */
    public static  <T> Result<T> error(CodeMsg codeMsg){
        return new Result<T>(codeMsg);
    }
    
    private Result(T data) {
        this.data = data;
    }
    
    private Result(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }
    
    private Result(CodeMsg codeMsg) {
        if(codeMsg != null) {
            this.code = codeMsg.getCode();
            this.msg = codeMsg.getMsg();
        }
    }
    
    
    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 T getData() {
        return data;
    }
    public void setData(T data) {
        this.data = data;
    }
}

這樣的好處是對參數校驗只要添加注解就可以了。參數校驗不通過會拋出BindException異常，BindException被全局異常處理器捕獲，將錯誤信息返回給前端。

而且異常處理器也會捕獲自定義的異常。

 

BindException