mqtt/src/main/java/com/xydl/util/FormatUtil.java

package com.xydl.util;

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

import java.util.*;

public class FormatUtil {

    public static String list2Json(List list){
        ObjectMapper objectMapper = new ObjectMapper();
        List<Map<String,Object>> assetList = new ArrayList<>();
        assetList.add(new HashMap<String,Object>(){{
            put("AssetCode","ironCore");
            put("AttributeList",list);
            put("Timestamp", new Date().getTime());
        }});
        Map<String,Object> resultMap = new HashMap<String,Object>(){{
            put("AssetList",assetList);
        }};
        String jsonString = null;
        try {
            jsonString = objectMapper.writeValueAsString(resultMap);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
        return jsonString;
    }

    public static void main(String[] args) {
        System.out.println(new Date().getTime());
    }


}