通过Spring Validation校验配置

一、内置注解校验

1. 新建Properties配置类ApplicationProperties；
2. 添加@Validated注解；

3. 需要校验的字段加上内置注解，例如@NotBlank注解。

   @Data
   @Component
   @Validated
   @ConfigurationProperties(prefix = "xxx.application")
   public class ApplicationProperties {
    /**
     * application name
     */
    @NotBlank(message = "xxx.application.name can not be blank")
    private String name;
   }

   二、自定义校验规则

4. 创建ConfigurationPropertiesValidator类，并实现Validator接口；

   public class ConfigurationPropertiesValidator implements Validator {
    @Override
    public boolean supports(Class<?> clazz) {
        Set<Class<?>> classSet = new HashSet<>();
        classSet.add(ImProperties.class);
        classSet.add(VodProperties.class);
        return classSet.contains(clazz);
    }
    @Override
    public void validate(Object target, Errors errors) {
        if (target instanceof ImProperties) {
            ImProperties imProperties = (ImProperties) target;
            if (imProperties.isEnableIm()) {
                if (imProperties.getSdkAppId() == null) {
                    errors.rejectValue("sdk-app-id", "null",
                            "xxx.enable-im equals true, xxx.im.sdk-app-id can not be null");
                }
                if (StringUtils.isBlank(imProperties.getAppKey())) {
                    errors.rejectValue("app-key", "blank",
                            "xxx.im.enable-im equals true, xxx.im.app-key can not be blank");
                }
            }
        } else if (target instanceof VodProperties) {
            VodProperties vodProperties = (VodProperties) target;
            if (vodProperties.isEnableAutoTranscode()) {
                if (vodProperties.getTranscodeDefinition() == null) {
                    errors.rejectValue("transcode-definition", "null",
                            "xxx.vod.enable-auto-transcode equals true, xxx.vod.transcode-definition can not be null");
                }
            }
            if (vodProperties.isEnableWatermark()) {
                if (vodProperties.getWatermarkDefinition() == null) {
                    errors.rejectValue("watermark-definition", "null",
                            "xxx.vod.enable-watermark equals true, xxx.vod.watermark-definition can not be null");
                }
            }
            if (vodProperties.isEnableAutoAiRecognition()) {
                if (vodProperties.getAiRecognitionDefinition() == null) {
                    errors.rejectValue("ai-recognition-definition", "null",
                            "xxx.vod.enable-auto-ai-recognition equals true, xxx.vod.ai-recognition-definition can not be null");
                }
            }
        }
    }
   }

5. 向容器中注册Bean，且Bean的name必须是configurationPropertiesValidator，否则无法校验。

   @Bean
   public ConfigurationPropertiesValidator configurationPropertiesValidator() {
    return new ConfigurationPropertiesValidator();
   }