Springboot-ObjectMapper类使用

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原创最新推荐文章于 2026-02-26 15:39:04 发布 7.3k 阅读 AI 写同款· GEO 优化 ›

[享学Jackson] 二十一、Spring Boot下的Jackson --- JacksonAutoConfiguration自动配置相信到了这里，你应该清楚本专栏讲解Jackson的脉络：**Jackson基础 -> Jackson进阶 -> Spring MVC下的Jackson -> Spring Boot下的Jackson**。不同于大多快餐式技术博客文章：只说其表，不道其里。上来就在`Spring Boot`环境下讲解Jackson，我觉得是不妥的，这**特别容易对小伙伴对Jackson的了解造成误导**，这是我比较可担忧的。读本文之前，我强烈建议你已经了解过**前二十篇文章**的描述和知识铺陈，因为本专栏不仅仅只希望你懂阅读详情

springboot文档中提供了三种关于json的操作方式，Gson、Jackson、JSON-B，其中Jackson是默认配置，也就是说在springboot项目中可以使用如下方式直接使用

@Autowired
ObjectMapper objectMapper;

我自己简单封装了下ObjectMapper 使用泛型来适应java bean、集合类list、map和json的互转，代码如下


import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.List;
import java.util.Map;


public class JsonMapper {

    private static ObjectMapper objectMapper;

    private static JsonMapper jsonMapper = new JsonMapper();

    private JsonMapper() {
        objectMapper = new ObjectMapper();
        objectMapper.configure(JsonParser.Feature.ALLOW_COMMENTS, true);
        objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
        objectMapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
        objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true);
    }
    public static JsonMapper getInstance() {
        return jsonMapper;
    }

    public <T> String toJson(T t) {
        String result = null;
        try {
            result = objectMapper.writeValueAsString(t);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return result;
    }

    public <T> T fromJson(Object value, Class<T> t) {
        T result = null;
        try {
            result = objectMapper.readValue(value.toString(), t);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }


    public <T> List<T> fromJson(Object value, Class cls, Class<T> t) {
        List<T> result = null;
        try {
            JavaType type = objectMapper.getTypeFactory().constructCollectionType(cls, t);
            result = objectMapper.readValue(value.toString(), type);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }

    public <K,V> Map<K,V> fromJson(Object object, Class cls, Class<K> key, Class<V> value) {
        Map<K,V> result = null;
        try {
            JavaType type = objectMapper.getTypeFactory().constructMapLikeType(cls, key, value);
            result = objectMapper.readValue(object.toString(), type);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }
}

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