Java参数校验Validator与@AssertTrue深度解析

<dependency>
    <groupId>javax.validation</groupId>
    <artifactId>validation-api</artifactId>
    <version>2.0.1.Final</version>
</dependency>
<dependency>
    <groupId>org.hibernate.validator</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>6.1.5.Final</version>
</dependency>

@Data
public class ImageRequest {
    /**
     * 图片URL地址
     */
    @Pattern(regexp = "^(http|https)://.*", message = "图片URL格式不正确")
    @Size(max = 1024, message = "图片URL长度不能超过1024个字符")
    private String imageUrl;
    /**
     * Base64编码的图片数据
     */
    @Size(max = 10 * 1024 * 1024, message = "Base64图片数据不能超过10MB")
    private String base64Image;
    /**
     * 设备编号
     */
    @NotBlank(message = "设备编号不能为空")
    private String deviceNo;
    /**
     * 用户标识
     */
    @NotBlank(message = "用户标识不能为空")
    private String userId;
    /**
     * 自定义校验方法：确保至少提供一种图片数据
     */
    @AssertTrue(message = "必须提供图片URL或Base64编码图片数据其中之一")
    public boolean isImageDataValid() {
        return StringUtils.isNotBlank(imageUrl) || StringUtils.isNotBlank(base64Image);
    }
}

public class ValidationExample {
    private final Validator validator;
    public ValidationExample() {
        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
        this.validator = factory.getValidator();
    }
    public void validateRequest(ImageRequest request) {
        // 执行校验
        Set<ConstraintViolation<ImageRequest>> violations = validator.validate(request);
        // 如果存在校验错误
        if (!violations.isEmpty()) {
            // 收集所有验证错误信息
            String errorMessage = violations.stream()
                    .map(ConstraintViolation::getMessage)
                    .collect(Collectors.joining("; "));
            log.error("参数校验失败：{}", errorMessage);
            throw new IllegalArgumentException("参数校验失败：" + errorMessage);
        }
    }
}

@AssertTrue(message = "校验失败的提示信息")
public boolean isXxxValid() {
    // 校验逻辑
    return true/false;
}

@AssertTrue(message = "付款方式只能选择其中一种")
public boolean isPaymentMethodValid() {
    return (alipay != null) ^ (wechatPay != null);
}

@AssertTrue(message = "当选择快递配送时，收货地址不能为空")
public boolean isDeliveryAddressValid() {
    return !DeliveryType.EXPRESS.equals(deliveryType) || 
           StringUtils.isNotBlank(deliveryAddress);
}

@AssertTrue(message = "结束时间必须晚于开始时间")
public boolean isTimeRangeValid() {
    return endTime != null && startTime != null && 
           endTime.after(startTime);
}

public interface Create {}
public interface Update {}
@AssertTrue(message = "创建时的校验规则", groups = {Create.class})
public boolean isCreateValid() {
    return ...;
}
@AssertTrue(message = "更新时的校验规则", groups = {Update.class})
public boolean isUpdateValid() {
    return ...;
}

@AssertTrue(message = "图片数据格式校验失败")
public boolean isImageFormatValid() {
    if (StringUtils.isNotBlank(imageUrl)) {
        return imageUrl.startsWith("http") && 
               (imageUrl.endsWith(".jpg") || imageUrl.endsWith(".png"));
    }
    if (StringUtils.isNotBlank(base64Image)) {
        return base64Image.startsWith("data:image/");
    }
    return false;
}