Jackson 自定义序列化和反序列化

1. 创建序列化类

继承JsonSerializer或者StdSerializer，添加泛型
自定义字符串序列化类，md5脱敏

package com.example.fisher.gradledemo.sysuser.entity;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import org.springframework.util.DigestUtils;

import java.io.IOException;

public class StringJsonSerializer extends JsonSerializer<String> {
    
    

    @Override
    public void serialize(String value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
    
    
        if (value != null) {
    
    
            String s = DigestUtils.md5DigestAsHex(value.getBytes("UTF-8"));
            gen.writeString(s);
        }
    }
}

自定义日期序列化类，转时间戳

package com.example.fisher.gradledemo.sysuser.entity;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;

import java.io.IOException;
import java.time.LocalDateTime;
import java.time.ZoneOffset;

public class LocalDateTime2Long extends StdSerializer<LocalDateTime> {
    
    

    public LocalDateTime2Long() {
    
    
        super(LocalDateTime.class);
    }

    @Override
    public void serialize(LocalDateTime value, JsonGenerator gen, SerializerProvider provider) throws IOException {
    
    
        Long epochSecond = value.toEpochSecond(ZoneOffset.ofHours(8));
        gen.writeObject(epochSecond);
    }
}

2. 创建反序列化类

继承JsonDeserializer

package com.example.fisher.gradledemo.sysuser.entity;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;

import java.io.IOException;

public class AgeDeserializer extends JsonDeserializer<Integer> {
    
    

    @Override
    public Integer deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
    
    
        int intValue = p.getIntValue();
        return intValue * 10;
    }
}

3. 实体类字段添加注解

序列化@JsonSerialize，反序列化@JsonDeserialize

package com.example.fisher.gradledemo.sysuser.entity;

import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableLogic;
import com.baomidou.mybatisplus.extension.activerecord.Model;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import lombok.Data;

import java.io.Serializable;
import java.time.LocalDateTime;

@SuppressWarnings("serial")
@Data
public class SysUser extends Model<SysUser> {
    
    

    @TableId(type = IdType.AUTO)
    private Long userId;

    @JsonSerialize(using = LocalDateTime2Long.class)
    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;

    @TableField(fill = FieldFill.UPDATE)
    private LocalDateTime updateTime;

    @TableLogic
    @JsonIgnore
    private Integer delFlag;

    @JsonSerialize(using = StringJsonSerializer.class)
    private String name;

    @JsonDeserialize(using = AgeDeserializer.class)
    private Integer age;

    private String interest;

    /**
     * 获取主键值
     *
     * @return 主键值
     */
    @Override
    public Serializable pkVal() {
    
    
        return this.userId;
    }
}