java 读取数据库数据写入到内存

1. 背景描述：公司开发的系统需要和别的公司的系统对接，其中有些数据本公司系统和其他公司的系统有些业务数据的标识不一样，在对接时数据库新建了一张表来描述这种对应关系，但是为了实现获取的高效性，从数据库获取到全部的数据，然后写入到内存中，需要时从内存中调用，提升效率。
2. 具体代码实现

package cn.shanxincd.ih.supervise.utils;

import cn.shanxincd.ih.supervise.service.BusConfigService;
import com.alibaba.fastjson.JSON;
import org.apache.commons.lang3.concurrent.BasicThreadFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;


@Service
public class DataMapUtil {
    @Autowired
    private BusConfigService busConfigService;

    private static final Logger LOGGER = LoggerFactory.getLogger(DataMapUtil.class);
    
    private static final Integer EXPIRE_SENCOND = 60 * 60;
    
    private static final ConcurrentHashMap DATA_MAP = new ConcurrentHashMap();

    
    public static final String CONFIG_LIST = "config_list";

    
    public Map getDataMap() {
        return DATA_MAP;
    }

    
    @PostConstruct
    public void initMethod() {
        ExecutorService pool = new ThreadPoolExecutor(1, 1, 0L,
                TimeUnit.MILLISECONDS, new LinkedBlockingQueue(1),
                new BasicThreadFactory.Builder().namingPattern("data-map-pool-%d").daemon(true).build(),
                new ThreadPoolExecutor.AbortPolicy());
        pool.execute(new Task());
        pool.shutdown();
    }

    
    private void initDataMap() {
        // test表数据
        setDataMap(CONFIG_LIST, busConfigService.list());
    }

    
    public static  T getObject(String key, Class clazz) {
        return json2Object(DATA_MAP.get(key), clazz);
    }

    public static  List getList(String key, Class clazz) {
        return json2List(DATA_MAP.get(key), clazz);
    }

    private  void setDataMap(String key, T value) {
        DATA_MAP.put(key, object2Json(value));
    }

    private  void setDataMap(String key, List value) {
        DATA_MAP.put(key, list2Json(value));
    }

    
    public static  T json2Object(String json, Class clazz) {
        try {
            return JSON.parseObject(json, clazz);
        } catch (Exception e) {
            LOGGER.error("{} 转 JSON 失败", json);
        }
        return null;
    }

    
    public static  String object2Json(T object){
        String json = JSON.toJSONString(object);
        return json;
    }

    
    public static  String list2Json(List list) {
        String jsons = JSON.toJSONString(list);
        return jsons;
    }

    
    public static  List json2List(String json, Class clazz) {
        List list = JSON.parseArray(json, clazz);
        return list;
    }

    
    class Task implements Runnable {
        @Override
        public void run() {
            while (true) {
                initDataMap();
                LOGGER.info("###################初始化数据#######################");
                try {
                    Thread.sleep(EXPIRE_SENCOND * 1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }

}

3. 具体的调用示例