使用jackson将json转换为对象时，自定义转换字段内容

前言

本文中采用的是继承JsonDeserializer抽象类 + 注解的方式实现自定义转换字段内容。

实体类

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.qf.utils.json.TestCustomDateDeserializer;
import lombok.Data;/*** @author qf* @since 2024/09/09 19:54*/
@Data
public class DataBo {@JsonProperty("name")@JsonDeserialize(using = TestCustomDateDeserializer.class)private String name;private String value;
}

工具类

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;import java.io.IOException;
import java.util.List;/*** jackson工具类** @author qf* @since 2024/09/09 19:56*/
public class JacksonUtil {private static class SingletonHolder {private static ObjectMapper mapper = new ObjectMapper();static {// 在构造器中进行配置//反序列化的时候如果多了其他属性,不抛出异常mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);}}public static ObjectMapper getSingleton() {ObjectMapper mapper = SingletonHolder.mapper;return mapper;}/*** 对象转json** @param obj* @return* @throws JsonProcessingException*/public static String toJson(Object obj) throws JsonProcessingException {ObjectMapper mapper = getSingleton();return mapper.writeValueAsString(obj);}/*** json转为对象** @param json* @param clazz* @param <T>* @return* @throws IOException*/public static <T> T toObject(String json, Class<T> clazz) throws IOException {ObjectMapper mapper = getSingleton();return mapper.readValue(json, clazz);}/*** 通过字段名拿数据* jsonNode.get("xxx").toString();* 如果是数组* jsonNode.get("xxx").get(0).toString();* ...* jsonNode.get("xxx").get(n).toString();** @param json* @return* @throws IOException*/public static JsonNode getJsonNode(String json) throws IOException {ObjectMapper mapper = getSingleton();JsonNode jsonNode = mapper.readTree(json);return jsonNode;}/*** json转换为目标类型的列表。** @param json          JSON字符串* @param typeReference 目标类型的TypeReference* @param <T>           泛型类型* @return 转换后的列表* @throws IOException 如果读取失败*/public static <T> List<T> toList(String json, TypeReference<List<T>> typeReference) throws IOException {ObjectMapper mapper = getSingleton();return mapper.readValue(json, typeReference);}}

继承JsonDeserializer的子类

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;import java.io.IOException;/*** @author qf* @since 2024/09/09 20:03*/
public class TestCustomDateDeserializer extends JsonDeserializer<String> {@Overridepublic String deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {String dateStr = p.getText();if("zs".equals(dateStr)){return "zhangsan";}return dateStr;}
}

测试类

import java.io.IOException;/*** @author qf* @since 2024/09/09 20:04*/
public class Test {public static void main(String[] args) throws IOException {String json = "{\"name\":\"zs\",\"value\":\"11\"}";DataBo bo = JacksonUtil.toObject(json, DataBo.class);System.out.println(bo);}
}