https://github.com/alibaba/fastjson/wiki/PropertyProcessable_cn
https://www.cnblogs.com/ariter/p/14254342.html

序列化时处理数据

1、自定义注解用来标识json数据需要处理的属性

import java.lang.annotation.*;

/**
 * 用于标识需要加密的字段
 */
@Target({ElementType.FIELD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface EncryptionField {

}

2、fastJson的值过滤器，对使用【EncryptionField】标注的字段加密

import com.alibaba.fastjson.serializer.ValueFilter;
import com.sinosoft.encrypt.utils.CryptoUtil;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Value;

import java.lang.reflect.Field;
import java.util.Objects;

/**
 * 对使用【EncryptionField】标注的字段加密
 */
public class EncryptionFieldFilter implements ValueFilter {
    /**
     * 加密key
     */
    @Value("${privacy.crypto.key}")
    private String encryptKey;

    public EncryptionFieldFilter() {

    }

    @Override
    public Object process(Object object, String name, Object value) {
        try {
            Field field = object.getClass().getDeclaredField(name);
            if (Objects.isNull(value) || String.class != field.getType() || (field.getAnnotation(EncryptionField.class)) == null) {
                return value;
            }
            if (StringUtils.isEmpty(field.toString())) {
                return value;
            }
            return CryptoUtil.sm4Encrypt(value.toString(), encryptKey);
        } catch (Exception e) {
        }
        return value;
    }
}

3、在需要处理的属性上增加注解

import com.cbex.partyconstruction.common.annotation.EncryptionField;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.experimental.Accessors;

@Data
@Accessors(chain = true)
public class MyPartyManageInfo {
    @ApiModelProperty(value = "职工姓名")
    private String name;

    @ApiModelProperty(value = "证件类型")
    private String cardType;

    @ApiModelProperty(value = "证件号码")
    @EncryptionField
    private String cardId;
}

将对象转换成json串

public class Test {
    public static void main(String[] args) throws Exception {
        MyPartyManageInfo partyManageInfo = new MyPartyManageInfo();
        partyManageInfo.setCardId("111111")
                .setCardType("居民身份证")
                .setName("职工");
        String s = JSONObject.toJSONString(partyManageInfo,new EncryptionFieldFilter());
        System.out.println("card加密后的Json串是------"+s);
       
    }


}

结果如下图，证件号码加密了

反序列化时处理json数据中的值

1、定义类实现PropertyProcessable 接口，处理需要处理的属性值

PropertyProcessable是1.2.35版本开始支持的自定义反序列化接口。

interface PropertyProcessable {
    // 返回property的类型，如果返回空，则由parser自行推断。
    Type getType(String name);

    // 处理属性值
    void apply(String name, Object value);
}

import com.alibaba.fastjson.parser.deserializer.PropertyProcessable;
import com.sinosoft.encrypt.utils.CryptoUtil;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import org.apache.commons.lang3.StringUtils;

import java.lang.reflect.Type;

@Data
public class MyPropertyProcessableResolver implements PropertyProcessable {

    @ApiModelProperty(value = "职工姓名")
    private String name;

    @ApiModelProperty(value = "证件类型")
    private String cardType;

    @ApiModelProperty(value = "证件号码")
    private String cardId;

    public MyPropertyProcessableResolver() {

    }


    @Override
    public Type getType(String name) {
        return null;
    }

    @Override
    public void apply(String name, Object value) {
        if(StringUtils.equals("cardId",name)){
            this.cardId = CryptoUtil.sm4Decrypt(value.toString(), null);
        }else if(StringUtils.equals("cardType",name)){
            this.cardType = (String) value;
        }else if(StringUtils.equals("name",name)){
            this.name = (String) value;
        }
    }
}

2、反序列化

import com.alibaba.fastjson.JSONObject;
import com.cbex.partyconstruction.common.annotation.EncryptionFieldFilter;
import com.cbex.partyconstruction.manage.domain.po.MyPartyManageInfo;
import com.cbex.partyconstruction.manage.domain.po.MyPropertyProcessableResolver;

public class Test {
    public static void main(String[] args) throws Exception {
        MyPartyManageInfo partyManageInfo = new MyPartyManageInfo();
        partyManageInfo.setCardId("111111")
                .setCardType("居民身份证")
                .setName("职工");
        String s = JSONObject.toJSONString(partyManageInfo,new EncryptionFieldFilter());
        System.out.println("card加密后的Json串是------"+s);
        MyPropertyProcessableResolver partyManageInfoVo = JSONObject.parseObject(s, MyPropertyProcessableResolver.class);
        System.out.println("json串转换成对象是------"+partyManageInfoVo);
    }
}