spring高级话题——定时任务

自spring3.1开始，其计划任务实现非常简单，首先，通过配置类注解@EnableScheduling来开启对计划任务的支持，然后在执行计划任务的方法上注解@Scheduled,声明这是一个计划任务。@Scheduled注解支持很多属性的配置，例如（cron、fixDelasy、fixRate）等

实例代码：

TaskSchedulerConfig.java

package com.minivison.caixing.learn.scheduled;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableScheduling;

/**
 *  

 *
 * @author caixing

 * @version 1.0

 * @taskId 

 * @CreateDate 2018年04月17日 

 */
@Configuration
@ComponentScan("com.minivison.caixing.learn.scheduled")
@EnableScheduling
public class TaskSchedulerConfig {

}

TaskService.java

package com.minivison.caixing.learn.scheduled;

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 *  

 *
 * @author caixing

 * @version 1.0

 * @taskId 

 * @CreateDate 2018年04月17日 

 */
@Service
public class TaskService {
    private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("HH:mm:ss");

    @Scheduled(fixedRate = 5000)
    public void reportCurrectTime(){
        System.out.println("每个5秒执行一次"+DATE_FORMAT.format(new Date()));
    }

    @Scheduled(cron = "0 52 16 * * *")
    public void fixTimeExecution(){
        System.out.println("在指定时间"+DATE_FORMAT.format(new Date())+"执行");
    }


}

Main.java

package com.minivison.caixing.learn;

import com.minivison.caixing.learn.scheduled.TaskSchedulerConfig;
import com.minivison.caixing.learn.scheduled.TaskService;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import javax.imageio.stream.FileImageInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;

/**
 *  

 *
 * @author caixing

 * @version 1.0

 * @taskId 

 * @CreateDate 2018年04月12日 

 */
public class Main {
    public static void main(String[] args) throws Exception {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(TaskSchedulerConfig.class);
        //TaskService service = context.getBean(TaskService.class);
        //service.reportCurrectTime();
        //context.close();
        //String str = Base64Utils.encodeToString(image2byte("E:\\123.jpg"));
        //System.out.println(str);

    }

    public static byte[] image2byte(String path) {
        byte[] data = null;
        FileImageInputStream input = null;
        try {
            input = new FileImageInputStream(new File(path));
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            byte[] buf = new byte[1024];
            int numBytesRead = 0;
            while ((numBytesRead = input.read(buf)) != -1) {
                output.write(buf, 0, numBytesRead);
            }
            data = output.toByteArray();
            output.close();
            input.close();
        } catch (FileNotFoundException ex1) {
            ex1.printStackTrace();
        } catch (IOException ex1) {
            ex1.printStackTrace();
        }
        return data;
    }
}