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。
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
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;
}