Java MapperUtils 工具类

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MapperUtils

为使用Jackson类包进行序列化、反序列化操作的同学开发方便，我们抽象出了一些通用的方法：

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Jackson 工具类
 *
 * @author liuxiaojun
 * @date 2019-03-02 21:09
 * ------------------- History -------------------
 *              
 * 2019-03-02   liuxiaojun     初始创建
 * -----------------------------------------------
 */
public class MapperUtils {
    private final static ObjectMapper objectMapper = new ObjectMapper();

    public static ObjectMapper getInstance() {
        return objectMapper;
    }

    /**
     * 转换为 JSON 字符串
     *
     * @param obj
     * @return
     * @throws Exception
     */
    public static String obj2json(Object obj) throws Exception {
        return objectMapper.writeValueAsString(obj);
    }

    /**
     * 转换为 JSON 字符串，忽略空值
     *
     * @param obj
     * @return
     * @throws Exception
     */
    public static String obj2jsonIgnoreNull(Object obj) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        return mapper.writeValueAsString(obj);
    }

    /**
     * 转换为 JavaBean
     *
     * @param jsonString
     * @param clazz
     * @return
     * @throws Exception
     */
    public static  T json2pojo(String jsonString, Class clazz) throws Exception {
        objectMapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
        return objectMapper.readValue(jsonString, clazz);
    }

    /**
     * 字符串转换为 Map
     *
     * @param jsonString
     * @return
     * @throws Exception
     */
    public static  Map json2map(String jsonString) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        return mapper.readValue(jsonString, Map.class);
    }

    /**
     * 字符串转换为 Map
     */
    public static  Map json2map(String jsonString, Class clazz) throws Exception {
        Map> map = objectMapper.readValue(jsonString, new TypeReference>() {
        });
        Map result = new HashMap();
        for (Map.Entry> entry : map.entrySet()) {
            result.put(entry.getKey(), map2pojo(entry.getValue(), clazz));
        }
        return result;
    }

    /**
     * 深度转换 JSON 成 Map
     *
     * @param json
     * @return
     */
    public static Map json2mapDeeply(String json) throws Exception {
        return json2MapRecursion(json, objectMapper);
    }

    /**
     * 把 JSON 解析成 List，如果 List 内部的元素存在 jsonString，继续解析
     *
     * @param json
     * @param mapper 解析工具
     * @return
     * @throws Exception
     */
    private static List