通过注解实现接口返回数据脱敏

xlc5202022年8月7日
大约 2 分钟约 664 字

通过注解实现接口返回数据脱敏

思路

1.要做成可配置多策略的脱敏操作,要不然一个个接口进行脱敏操作,重复的工作量太多,很显然违背了“多写一行算我输”的程序员规范,思来想去,定义数据脱敏注解和数据脱敏逻辑的接口, 在返回类上,对需要进行脱敏的属性加上,并指定对应的脱敏策略操作

2.接下来我只需要拦截控制器返回的数据,找到带有脱敏注解的属性操作即可,一开始打算用@ControllerAdvice去实现,但发现需要自己去反射类获取注解,当返回对象比较复杂,需要递归去反射,性能一下子就会降低,于是换种思路,我想到平时使用的@JsonFormat,跟我现在的场景很类似,通过自定义注解跟字段解析器,对字段进行自定义解析,tql

代码

1. 自定义数据注解,并可以配置数据脱敏策略

@Target({ElementType.FIELD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DataMasking {

    DataMaskingFunc maskFunc() default DataMaskingFunc.NO_MASK;

}

2. 自定义Serializer,参考jackson的StringSerializer,下面的示例只针对String类型进行脱敏

public interface DataMaskingOperation {

    String MASK_CHAR = "*";
    
    String mask(String content, String maskChar);

}


public enum DataMaskingFunc {

     /**
     *  脱敏转换器
     */
     NO_MASK((str, maskChar) -> {
        return str;
     }),
     ALL_MASK((str, maskChar) -> {
        if (StringUtils.hasLength(str)) {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < str.length(); i++) {
                sb.append(StringUtils.hasLength(maskChar) ? maskChar : DataMaskingOperation.MASK_CHAR);
            }
            return sb.toString();
        } else {
            return str;
        }
    });

    private final DataMaskingOperation operation;

    private DataMaskingFunc(DataMaskingOperation operation) {
        this.operation = operation;
    }

    public DataMaskingOperation operation() {
        return this.operation;
    }

}


public final class DataMaskingSerializer extends StdScalarSerializer<Object> {
    private final DataMaskingOperation operation;

    public DataMaskingSerializer() {
        super(String.class, false);
        this.operation = null;
    }

    public DataMaskingSerializer(DataMaskingOperation operation) {
        super(String.class, false);
        this.operation = operation;
    }


    public boolean isEmpty(SerializerProvider prov, Object value) {
        String str = (String)value;
        return str.isEmpty();
    }

    public void serialize(Object value, JsonGenerator gen, SerializerProvider provider) throws IOException {
        if (Objects.isNull(operation)) {
            String content = DataMaskingFunc.ALL_MASK.operation().mask((String) value, null);
            gen.writeString(content);
        } else {
            String content = operation.mask((String) value, null);
            gen.writeString(content);
        }
    }

    public final void serializeWithType(Object value, JsonGenerator gen, SerializerProvider provider, TypeSerializer typeSer) throws IOException {
        this.serialize(value, gen, provider);
    }

    public JsonNode getSchema(SerializerProvider provider, Type typeHint) {
        return this.createSchemaNode("string", true);
    }

    public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint) throws JsonMappingException {
        this.visitStringFormat(visitor, typeHint);
    }
}


3. 自定义AnnotationIntrospector,适配我们自定义注解返回相应的Serializer

@Slf4j
public class DataMaskingAnnotationIntrospector extends NopAnnotationIntrospector {

    @Override
    public Object findSerializer(Annotated am) {
        DataMasking annotation = am.getAnnotation(DataMasking.class);
        if (annotation != null) {
            return new DataMaskingSerializer(annotation.maskFunc().operation());
        }
        return null;
    }

}

4. 覆盖ObjectMapper

@Configuration(
        proxyBeanMethods = false
)
public class DataMaskConfiguration {

    @Configuration(
            proxyBeanMethods = false
    )
    @ConditionalOnClass({Jackson2ObjectMapperBuilder.class})
    static class JacksonObjectMapperConfiguration {
        JacksonObjectMapperConfiguration() {
        }

        @Bean
        @Primary
        ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
            ObjectMapper objectMapper = builder.createXmlMapper(false).build();
            AnnotationIntrospector ai = objectMapper.getSerializationConfig().getAnnotationIntrospector();
            AnnotationIntrospector newAi = AnnotationIntrospectorPair.pair(ai, new DataMaskingAnnotationIntrospector());
            objectMapper.setAnnotationIntrospector(newAi);
            return objectMapper;
        }
    }

}

5. 返回对象加上注解

public class User implements Serializable {
    /**
     * 主键ID
     */
    private Long id;

    /**
     * 姓名
     */
    @DataMasking(maskFunc = DataMaskingFunc.ALL_MASK)
    private String name;

    /**
     * 年龄
     */
    private Integer age;

    /**
     * 邮箱
     */
    @DataMasking(maskFunc = DataMaskingFunc.ALL_MASK)
    private String email;

}