java多线程实践-白红宇

java多线程实践

阅读量：6617 次

发布时间：2019-06-25

本文共 5174 字，大约阅读时间需要 17 分钟。

因为公司业务需要，需要用到多线程。

一种方法是我百度spring 多线程的解决方案。

配置文件

实现类

/** * 这里采用了Callable接口，是因为这种方式比Runable多了返回，更加适合与单元测试 */@Component@Scope("prototype")public class IOrderListVer2Task implements Callable
    
     , Serializable {    private static final long serialVersionUID = -6626027616177700489L;    @Autowired    private IOrderListVer2Service orderListVer2Service;    private String client;    private String topType;    public void setClient(String client) {        this.client = client;    }    public void setTopType(String topType) {        this.topType = topType;    }    /**     * Computes a result, or throws an exception if unable to do so.     *     * @return computed result     * @throws Exception if unable to compute a result     */    @Override    public String call() throws Exception {        orderListVer2Service.getOrderList(client,topType);        return "调用成功";    }}

测试方法

/**	 * 比较推荐这种方法，因为这种方法更容易扩展	 */	@Test	public void test(){//		ThreadPoolTaskExecutor poolTaskExecutor = SpringContextUtil.getBean(ThreadPoolTaskExecutor.class);		try {			String[] clients = {"",""};			String[] topTypes = {"",""};			int count = 0;			for(String client:clients){				for(String topType:topTypes){					IOrderListVer2Task task = SpringContextUtil.getBean(IOrderListVer2Task.class);					task.setClient(client);					task.setTopType(topType);					Future
    
      future = taskExecutor.submit(task);					System.out.println(future.get());				}			}		}catch (Exception e){			e.printStackTrace();		}	}

另一种方法是不用spring来实现多线程。

/** * @author zengrong.gzr * @date 2017/04/18 */public class ThreadExecutors {    private static ReentrantLock lock = new ReentrantLock();    private ThreadPoolExecutor threadPoolExecutor;    private static ThreadExecutors instance;    //默认超时两百毫秒    private static final long DEFAULT_TIME_OUT = 200;    public static ThreadExecutors getInstance() {        if (instance == null) {            lock.lock();            try {                if （instance == null) {                    instance = new ThreadExecutors();                }            } finally {                lock.unlock();            }        }        return instance;    }    private ThreadExecutors() {        threadPoolExecutor = new ThreadPoolExecutor(100, 500, 100000L, TimeUnit.MILLISECONDS,                new ArrayBlockingQueue
    
     (2000), new ThreadPoolExecutor.CallerRunsPolicy());    }    public 
     
       Future
      
        submit(Callable
       
         t) {        return threadPoolExecutor.submit(t);    }    public 
        
          List
         
          
           > invokeAll(List
           
            
             > tasks, long timeOutMills) { try { if (timeOutMills <= 0) { timeOutMills = DEFAULT_TIME_OUT; } return threadPoolExecutor.invokeAll(tasks, timeOutMills, TimeUnit.MILLISECONDS); } catch (Throwable t) { return Lists.newArrayList(); } }}

在java8中，可以用lambda来简化代码

callables.add(() ->            {                try {                    activityPriceService.sendApiAndUpdateActivityPrice(activityPrice);                    return  activityPrice.getErpCode();                } catch (ApiException e) {                    e.printStackTrace();                    return "";                }            });Runnable task3 = () -> {                try {                    activityPriceService.sendApiAndUpdateActivityPrice(activityPrice);                } catch (ApiException e) {                    e.printStackTrace();                }            }; activityPrices.stream().forEach(activityPrice -> {            callables.add(() -> {                try {                    activityPriceService.sendApiAndUpdateActivityPrice(activityPrice);                    return activityPrice.getErpCode();                } catch (ApiException e) {                    e.printStackTrace();                    return "";                }            });        }); //这种方式是可以的            new Thread( () -> System.out.println("In Java8, Lambda expression rocks !!") ).start();//            new Callable
    
     ( () -> test(activityPrice) ).call();            Callable
     
       c = () -> () -> {                System.out.println("Hello from Callable");            }; Callable
      
       [] c3 =new Callable[]{ ()->test(activityPrice),                ()->"Hello from Callable b", ()->"Hello from Callable c" };  Callable
       
         c5 = () -> "Hello from Callable";            Callable
        
          c6 = () -> test(activityPrice);            callables.add(() -> test(activityPrice)); //下面是lambda的实现方式,可以参考一下        /*activityPrices.stream().forEach(activityPrice -> {            callables.add(() -> {                try {                    activityPriceService.sendApiAndUpdateActivityPrice(activityPrice);                    return activityPrice.getErpCode();                } catch (ApiException e) {                    e.printStackTrace();                    return null;                }            });        });*/