Java定时任务：使用 ScheduledExecutorService 创建定时任务

小鱼儿 2023-05-29 13:16 1阅读 0赞

使用ScheduledExecutorService scheduleAtFixedRate 实现定时任务：

1、Java代码

public class YdDataReader implements Runnable{
    
            //如果配置文件中的定时任务运行时间run_time为空，使用此默认时间
    	private static final String RUN_TIME_DEFAULT = "06:00:00";
    	
    	public static void main(String[] args) throws ParseException {
    		runTaskNow();
    		
    		ScheduledExecutorService pool = Executors.newSingleThreadScheduledExecutor();
    		YdDataReader task = new YdDataReader();
    		
    		Calendar now = Calendar.getInstance();
    		now.add(Calendar.DATE, 1); //天数加1
    		String runTime = getProperties().getProperty("run_time");
    		String tomorrowStr = new SimpleDateFormat("yyyy-MM-dd").format(now.getTime()) + " " + runTime;
    		Date tomorrow = null;
    		try {
    			tomorrow = sdf.parse(tomorrowStr);
    		} catch (ParseException e) {//如果配置文件中的run_time格式有异常，使用默认时间 RUN_TIME_DEFAULT，即 06:00:00
    			tomorrowStr = new SimpleDateFormat("yyyy-MM-dd").format(now.getTime()) + " " + RUN_TIME_DEFAULT;
    			tomorrow = sdf.parse(tomorrowStr);
    			logger.error("配置文件中任务运行时间 run_time 配置有误，使用默认时间： " + RUN_TIME_DEFAULT);
    		}
    		long currentTime = System.currentTimeMillis();//当前时间的毫秒数
    		long tomorrowTime = tomorrow.getTime();//明天任务运行时间的毫秒数
    		long minusTime = tomorrowTime - currentTime;//下次运行时间与当前时间相差毫秒数
    		pool.scheduleAtFixedRate(task, minusTime, 24 * 60 * 60 * 1000, TimeUnit.MILLISECONDS);	//24 * 60 * 60 * 1000: 一天的毫秒数
    		logger.info("定时任务已启动，将于 " + tomorrowStr + " 开始执行。");
    	}
    
    	private static void runTaskNow() {
    		//是否立即执行
    		String runTaskNow = getProperties().getProperty("lunch_run");
    		if("1".equals(runTaskNow)){
    			//TODO
    		}
    	}
    }
    
            //读取配置文件
    	private static Properties getProperties() {
    		Properties p = null;
    		try {
    			p = PropertiesUtil.readProperties(YD_CONF);
    		} catch (IOException e) {
    			logger.error("读取配置文件失败: " + YD_CONF);
    			e.printStackTrace();
    		}
    		return p;
    	}

2、工具类

import java.io.IOException;
    import java.io.InputStream;
    import java.util.Properties;
    
    public class PropertiesUtil {
    	
    	/**
    	 * 根据配置文件名称，返回Properties对象
    	 * properties.getProperty("ip").trim()
    	 * @return	Properties
    	 * @throws IOException 
    	 */
    	public static Properties readProperties(String propertiesName) throws IOException{
    		//读取properties配置文件
    		Properties properties = new Properties();
    		InputStream is = PropertiesUtil.class.getClassLoader().getResourceAsStream(propertiesName);//new BufferedInputStream(new FileInputStream("./conf/pue_conf.properties"));
    		properties.load(is);
    		return properties;
    	}
    }

3、配置文件:

# Run the task immediately after the project starts. 0:no; 1:yes.
    lunch_run = 0
    # The time when the task runs everyday. Format like "06:00:00"
    run_time = 06:00:00