一个注解搞定接口数据脱敏，太强了！

来源：juejin.cn/post/7110110794188062727

下午惬意时光，突然产品小姐姐走到我面前，打断我短暂的摸鱼time，企图与我进行深入交流，还好我早有防备没有闪，打开瑞star的点单页面，暗示没有一杯coffee解决不了的需求，需求是某些接口返回的信息，涉及到敏感数据的必须进行脱敏操作，我思考一反，表示某问题，马上安排。

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

Spring Boot 基础就不介绍了，推荐下这个实战教程：

https://github.com/javastacks/spring-boot-best-practice

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; }

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