初始化数据库数据到内存（实质保存到java对象）

Bertha 。 2022-07-13 06:53 192阅读 0赞

实现**InitializingBean**重写方法**afterPropertiesSet**

package com.util;
    
    import me.uding.repo.ConfigParamRepository;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.springframework.beans.factory.InitializingBean;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    
    import java.util.List;
    import java.util.Map;
    import java.util.concurrent.ConcurrentHashMap;
    
    
    @Component
    public class ConfigParamUtils implements InitializingBean {
    
        Log logger = LogFactory.getLog(ConfigParamUtils.class);
    
        private  ConcurrentHashMap<String,String> paramMap=new ConcurrentHashMap<String,String>();
    
        @Autowired
        ConfigParamRepository configParamRepository;
    
        public String getValue(String key) throws Exception {
            String value= paramMap.get(key);
            if(value==null){
                throw new Exception("Key:"+key+" get Value is NULL");
            }
            return value;
        }
    
        @Override
        public void afterPropertiesSet() throws Exception {
            initParamMap();
        }
    
        public void initParamMap(){
            //logger.info("Start init config from DB");
            List<Map<String, String>> maps=configParamRepository.queryConfigInfo();
    
            for (Map<String,String> tmp :maps){
                String key=tmp.get("config_key");
                String value=tmp.get("config_value");
                paramMap.put(key,value);
                //logger.info(String.format("Key:%s  Value:%s is add in Cache",key,value));
            }
        }
    }