1.前言

有时候，我们返回给前端的数据需要脱敏，避免用户信息被泄漏，就像你点外卖一样，京东或淘宝购物一样，手机号，姓名这些字段是被脱敏后的，在这个大数据时代，用户的数据安全是及其重要的。我们如何对用户统一数据进行脱敏处理呢？如果我们自定义脱敏方式，使用一个工具类，被改字段传递进去，脱敏后返回新的字符串，那这样是很多地方需要手动去编写很多重复的代码，而且不利于维护，比如是单个bean，或者是list的时候还要去遍历一次list。有没有什么方法统一处理呢？我们定义好脱敏规则，只需要在需要脱敏的字段上加上一个注解即可。那当然是可以的

2.脱敏注解

import com.fasterxml.jackson.annotation.JacksonAnnotationsInside;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.springboot.example.desensitizer.handler.SensitiveJsonSerialize;
import com.springboot.example.desensitizer.enums.SensitiveStrategy ;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 脱敏注解
 * @author compass
 * @date 2022-12-11
 * @since 1.0
 **/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
@JacksonAnnotationsInside
@JsonSerialize(using = SensitiveJsonSerialize.class)
public @interface Sensitive {

    SensitiveStrategy strategy();
}

3.定义好一套需要脱敏的规则

import java.util.function.Function;

/**
 * 对需要特别脱敏的字段指定脱敏规则
 * @author compass
 * @date 2022-12-11
 * @since 1.0
 **/
public enum SensitiveStrategy {
    /**
     * 对用户名进行脱敏，基于正则表达式实现
     */
    USERNAME(s -> s.replaceAll("(\\S)\\S(\\S*)", "$1*$2")),

    /**
     * 对身份证进行脱敏
     */
    ID_CARD(s -> s.replaceAll("(\\d{4})\\d{10}(\\w{4})", "$1****$2")),

    /**
     * 对电话号码进行脱敏
     */
    PHONE(s -> s.replaceAll("(\\d{3})\\d{4}(\\d{4})", "$1****$2")),

    /**
     * 对地址进行脱敏
     */
    ADDRESS(s -> s.replaceAll("(\\S{3})\\S{2}(\\S*)\\S{2}", "$1****$2****")),

    /**
     * 对密码进行脱敏，全部加密即可
     */
    PASSWORD(s -> "********");


    private final Function<String, String> desensitizeSerializer;

    SensitiveStrategy(Function<String, String> desensitizeSerializer) {
        this.desensitizeSerializer = desensitizeSerializer;
    }

    // 用于后续获取脱敏的规则，实现脱敏
    public  Function<String, String> desensitizeSerializer() {
        return desensitizeSerializer;
    }


}

4.自定义JSON序列化

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.BeanProperty;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.ser.ContextualSerializer;
import com.springboot.example.desensitizer.annotations.Sensitive;
import com.springboot.example.desensitizer.enums.SensitiveStrategy;

import java.io.IOException;
import java.util.Objects;

/**
 * @author compass
 * @date 2022-12-11
 * @since 1.0
 **/
public class SensitiveJsonSerialize  extends JsonSerializer<String> implements ContextualSerializer {

    private SensitiveStrategy strategy;

    // 在序列化时进行数据脱敏
    @Override
    public void serialize(String value, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {

        jsonGenerator.writeString(strategy.desensitizeSerializer().apply(value));
    }

    // 获取注解上的属性
    @Override
    public JsonSerializer<?> createContextual(SerializerProvider provider, BeanProperty property) throws JsonMappingException {
        Sensitive annotation = property.getAnnotation(Sensitive.class);
        if (Objects.nonNull(annotation) && Objects.equals(String.class, property.getType().getRawClass())) {
            // 主要代码在这里，获取脱敏的规则
            this.strategy = annotation.strategy();
            return this;
        }
        return provider.findValueSerializer(property.getType(), property);

    }
}

5.在实体类上标注对应的脱敏规则

@Data
@ToString
public class Employee {
    private Long id;

    @Sensitive(strategy = SensitiveStrategy.USERNAME)
    private String name;

    private String email;

    @Sensitive(strategy = SensitiveStrategy.ID_CARD)
    private String identity;

    @Sensitive(strategy = SensitiveStrategy.PASSWORD)
    private String password;

    @Sensitive(strategy = SensitiveStrategy.PHONE)
    private String phone;

    private Date birthday;

    private String jobNumber;

    private Boolean verified;

    @Sensitive(strategy = SensitiveStrategy.ADDRESS)
    private String address;

}

5.写一个接口进行测试

@RestController
@RequestMapping("/sensitiveStrategy")
public class SensitiveStrategyController {

    @GetMapping("/v1/getSensitiveStrategy")
    public ResponseResult<Employee> getSensitiveStrategy() {
        Employee employee = new Employee();
        employee.setId(IdUtil.getSnowflakeNextId());
        employee.setName("诸葛亮");
        employee.setEmail("360369395@qq.com");
        employee.setIdentity("522132188881017455X");
        employee.setPassword("");
        employee.setPhone("17785444960");
        employee.setBirthday(new Date());
        employee.setJobNumber(IdUtil.getSnowflake().nextIdStr());
        employee.setVerified(false);
        employee.setAddress("重庆市沙坪坝区大学城中路2-18号");

        return ResponseResult.success("请求成功", employee);
    }
}