扩展类会引发UnsatisfiedDependencyException异常

Question

我是构建web服务的新手，我开始使用spring boot构建web服务。我创建了以下controller类

package controller;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import model.Time;
import service.FeedService;

@RestController
public class FeedController extends ScheduledThreadPoolExecutor{

    public FeedController(int corePoolSize) {
        super(corePoolSize);
        // TODO Auto-generated constructor stub
    }
    int difference;
    int a;
    boolean schedule;
    //static as the variable is accessed across multiple threads
    @Autowired
    static FeedService fs;

    @RequestMapping(value="/test")
    public String test(){
        return "test";
    }



    @RequestMapping(value = "/schedule", method = RequestMethod.GET)
    public int ScheduleFeed(@RequestParam(value = "difference",required = false) String y) throws InterruptedException, ExecutionException{
//      if(y != null){
//          difference = Integer.parseInt(y);
            difference = 0;
            NewScheduledThreadPoolTest.mymethod(difference);
            return difference;

//      }else{
//          return -1;
//      }
    }

    @RequestMapping(value = "/inquireSchedule", method = RequestMethod.GET)
    public ResponseEntity<Time> RequestFeed(){
        if(schedule == true){
            schedule = fs.setFalse();
            return new ResponseEntity<Time>(HttpStatus.OK);
        }
        return new ResponseEntity<Time>(HttpStatus.BAD_REQUEST);

    }
    //schedule the task to happen after a certain number of times
    static class NewScheduledThreadPoolTest {
        public static void mymethod(int difference, final String... args) throws InterruptedException, ExecutionException {
            // creates thread pool with 1 thread
            System.out.println("hello world");
            final ScheduledExecutorService schExService = Executors.newScheduledThreadPool(2);
            // Object creation of runnable thread.
            final Runnable ob = new NewScheduledThreadPoolTest().new myclass();
            // Thread scheduling ie run it after "difference" hours before and then after every 24 hours later on
            schExService.scheduleWithFixedDelay(ob, difference, 24, TimeUnit.SECONDS);
            // waits for termination for 30 seconds only
            schExService.awaitTermination(30, TimeUnit.SECONDS);
            // shutdown now.
            schExService.shutdownNow();
            System.out.println("Shutdown Complete");
        }

    class myclass implements Runnable{

        @Override
        public void run() {
            try{
            // the mechanism to give a positive feedback to the arduino service
                fs.setTrue();
                System.out.println("hello world");
            }catch(Exception e){
                System.out.println("task failed");
                e.printStackTrace();
            }
        }}
    }
}

尝试运行我的web服务会导致它抛出以下异常：

但是，如果我移除“ScheduledThreadPoolExecutor”和构造函数，它运行良好。谁能解释一下扩展课程有什么问题吗？

注：

1）扩展类是在下面提到的文章中建议的，作为我最初问题的解决方案。最初，我的runnable在没有任何类型的通知或错误消息的情况下无法运行

http://code.nomad-labs.com/2011/12/09/mother-FK-the-scheduledexecutorservice/

Answer 1

不要使bean成员为静态的。它们是从多个线程引用的这一事实是不相关的；Spring的工作是确保填充了依赖项。

此外，与现场注入相比，优选施工注入；这使得这类问题的可能性大大降低。