多线程-线程池

 

 

 

 

代码如下：

public class Demo13 {
    public static void main(String[] args) {
        //1.创建服务，创建线程池,线程池大小10
        ExecutorService service = Executors.newFixedThreadPool(10);

        MyThread myThread = new MyThread();

        //执行
        service.execute(myThread);
        service.execute(myThread);
        service.execute(myThread);

        //2.关闭连接
        service.shutdown();

        /*MyThread ticket = new MyThread();
        new Thread(ticket,"小明").start();
        new Thread(ticket,"老师").start();
        new Thread(ticket,"黄牛").start();*/
    }
}
class MyThread implements Runnable{
    private int ticketNums = 10;
    private boolean flag = true;//外部停止方式

    @Override
    public void run() {
        while (flag){
            buy();
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    private synchronized void buy(){
        if (ticketNums <= 0){
            flag = false;
            return;
        }else {
            System.out.println(Thread.currentThread().getName()+"拿到了第"+ticketNums--+"张票");
        }
    }
}

 

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---

注意：springboot使用多线程

实现多线程的类是无法注入bean的，例如

 

 会报空指针异常。

解决方法是：

新建一个获取bean的工具类

package com.example.test.thread;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public class ApplicationContextProvider implements ApplicationContextAware {
/**
* 上下文对象实例
*/
private static ApplicationContext applicationContext;

@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}

/**
* 获取applicationContext
*
* @return
*/
public static ApplicationContext getApplicationContext() {
return applicationContext;
}

/**
* 通过name获取 Bean.
*
* @param name
* @return
*/
public static Object getBean(String name) {
return getApplicationContext().getBean(name);
}

/**
* 通过class获取Bean.
*
* @param clazz
* @param <T>
* @return
*/
public static <T> T getBean(Class<T> clazz) {
return getApplicationContext().getBean(clazz);
}

/**
* 通过name,以及Clazz返回指定的Bean
*
* @param name
* @param clazz
* @param <T>
* @return
*/
public static <T> T getBean(String name, Class<T> clazz) {
return getApplicationContext().getBean(name, clazz);
}
}

 

使用：创建一个无参的构造方法，在里面调用工具类的getBean（）方法即可。

 

private UserinfoService userinfoService;

public Running() {
this.userinfoService = ApplicationContextProvider.getBean(UserinfoService.class);
}