SpringBoot自定义校验注解

根据JSR303注解的规范，必须包含String message() Class[] groups() Class[] payload()

@ListValue的作用是只能接收在数组的值

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.ElementType.TYPE_USE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

@documented
@Constraint(validatedBy = { ListValueConstrainValidator.class}) //可以指定多个不同的校验器，适配不同的数据类型
@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE })
@Retention(RUNTIME)
public @interface ListValue {

    // 在ValidationMessages.properties文件中的字段
    String message() default "{com.atguigu.common.valid.ListValue.message}";

    Class[] groups() default { };

    Class[] payload() default { };

    int[] vals() default {};
}

通过@Constraint 与自己编写的校验器相关联，可以指定多个不同的校验器，适配不同的数据类型

实现 ConstraintValidator接口（Ctrl+Alt+B 查看接口的全部实现类）

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.util.HashSet;
import java.util.Set;


public class ListValueConstrainValidator implements ConstraintValidator {

    private Set set =new HashSet<>();
    //初始化方法
    @Override
    public void initialize(ListValue constraintAnnotation) {
        int[] vals = constraintAnnotation.vals();
        for (int val : vals) {
            set.add(val);
        }
    }

    // 判断是否校验成功

    

    @Override
    public boolean isValid(Integer value, ConstraintValidatorContext context) {
        return set.contains(value);
    }
}

import com.atguigu.common.exception.BizCodeEnum;
import com.atguigu.common.utils.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.HashMap;
import java.util.Map;


@Slf4j
@RestControllerAdvice(basePackages = "com.atguigu.gulimall.product.controller")
public class GulimallExceptionControllerAdvice {
    @ExceptionHandler(value = MethodArgumentNotValidException.class)
    public R handlevalidException(MethodArgumentNotValidException e) {
        log.error("数据校验出现问题{}，异常类型：{}", e.getMessage(), e.getClass());
        BindingResult bindingResult = e.getBindingResult();

        Map errorMap = new HashMap<>();
        bindingResult.getFieldErrors().forEach((fieldError -> {
            errorMap.put(fieldError.getField(), fieldError.getDefaultMessage());
        }));
        return R.error(BizCodeEnum.VALID_EXCEPTION.getCode(), BizCodeEnum.VALID_EXCEPTION.getMsg()).put("data", errorMap);
    }

    @ExceptionHandler(value = Throwable.class)
    public R HandleException(Throwable throwable){
        log.error("错误：",throwable);
        return R.error(BizCodeEnum.UNKNOW_EXCEPTION.getCode(),BizCodeEnum.UNKNOW_EXCEPTION.getMsg());
    }
}

@Slf4j是Lombok插件的注解， BizCodeEnum 是一个自定义的错误类型枚举类

@ListValue(vals={0,1}, groups = {AddGroup.class, UpdateGroup.class})
private Integer showStatus;

groups 选择校验的组， AddGroupt和UpdateGroup是自定义的空接口

使用我们自定义的注解来校验Controller类接收的实体类的值

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import com.atguigu.common.valid.AddGroup;
import com.atguigu.common.valid.UpdateGroup;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.validation.BindingResult;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.atguigu.gulimall.product.entity.BrandEntity;
import com.atguigu.gulimall.product.service.BrandService;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.R;

import javax.validation.Valid;



@RestController
@RequestMapping("product/brand")
public class BrandController {
    @Autowired
    private BrandService brandService;

    @RequestMapping("/save")
    // @RequiresPermissions("product:brand:save")
    public R save(@Validated({AddGroup.class}) @RequestBody BrandEntity brand){
      brandService.save(brand);

        return R.ok();
    }
}

@Valid不需要指定使用校验的组，全部校验注解都生效

@Validated在后面指定要使用校验的组，如果在实体类中的属性的校验注解不带对应的groups参数的话，则不会使用这个校验注解