使用多线程提高REST服务性能异步处理rest服务

约定不等于承诺〃 2022-05-10 04:26 160阅读 0赞

> 使用Runnable  
> 使用DeferredResult  
> 异步处理配置

## 异步处理 ##

![在这里插入图片描述][70]

## Callable ##

//		Callable<String> result = new Callable<String>() {
    //			@Override
    //			public String call() throws Exception {
    //				logger.info("副线程开始");
    //				Thread.sleep(1000);
    //				logger.info("副线程返回");
    //				return "success";
    //			}
    //		};

> 由主线程调用 子线程

## DeferredResult ##

![在这里插入图片描述][70 1]

> 线程1，和线程2 是 隔离的，谁也不知道谁的存在

### MockQueue ###

@Component
    public class MockQueue {
    	private String placeOrder; //提供get set
    	private String completeOrder;
    	private Logger logger = LoggerFactory.getLogger(getClass());
    	public void setPlaceOrder(String placeOrder) throws Exception {
    		new Thread(() -> {
    			logger.info("接到下单请求, " + placeOrder);
    			try {
    				Thread.sleep(1000);
    			} catch (Exception e) {
    				e.printStackTrace();
    			}
    			this.completeOrder = placeOrder;
    			logger.info("下单请求处理完毕," + placeOrder);
    		}).start();
    	}

### DeferredResultHolder ###

@Component
    public class DeferredResultHolder {
    //提供get set
    	private Map<String, DeferredResult<String>> map = new HashMap<String, DeferredResult<String>>();
    }

### QueueListener ###

@Component
    public class QueueListener implements ApplicationListener<ContextRefreshedEvent> {
    
    	@Autowired
    	private MockQueue mockQueue;
    
    	@Autowired
    	private DeferredResultHolder deferredResultHolder;
    	
    	private Logger logger = LoggerFactory.getLogger(getClass());
    
    	@Override
    	public void onApplicationEvent(ContextRefreshedEvent event) {
    		new Thread(() -> {
    			while (true) {
    
    				if (StringUtils.isNotBlank(mockQueue.getCompleteOrder())) {
    					//如果完成订单有值
    					String orderNumber = mockQueue.getCompleteOrder();
    					logger.info("返回订单处理结果:"+orderNumber);
    					//获取 DeferredResult 设置 返回值
    					deferredResultHolder.getMap().get(orderNumber).setResult("place order success");
    					mockQueue.setCompleteOrder(null);
    					
    				}else{
    					try {
    						Thread.sleep(100);
    					} catch (InterruptedException e) {
    						e.printStackTrace();
    					}
    				}
    
    			}
    		}).start();
    	}
    }

### AsyncController ###

@RestController
    public class AsyncController {
    	@Autowired
    	private MockQueue mockQueue;
    	@Autowired
    	private DeferredResultHolder deferredResultHolder;
    	private Logger logger = LoggerFactory.getLogger(getClass());
    	
    	@RequestMapping("/order")
    	public DeferredResult<String> order() throws Exception {
    		logger.info("主线程开始");
    		//随机生成一个8位的 号
    		String orderNumber = RandomStringUtils.randomNumeric(8);
    		//设置 
    		mockQueue.setPlaceOrder(orderNumber);
    		//创建 DeferredResult
    		DeferredResult<String> result = new DeferredResult<>();
    		//设置到deferredResultHolder
    		deferredResultHolder.getMap().put(orderNumber, result);
    		
    		return result;
    		
    	}
    
    }

## 多线程的配置 ##

@Configuration
    public class WebConfig extends WebMvcConfigurerAdapter {
    	
    	@SuppressWarnings("unused")
    	@Autowired
    	private TimeInterceptor timeInterceptor;
    
    	@Override
    	public void configureAsyncSupport(AsyncSupportConfigurer configurer) {
    		configurer.registerCallableInterceptors();//需要用这两个方法，单独注册拦截器
    		configurer.registerDeferredResultInterceptors();
    		configurer.setDefaultTimeout(); //超时
    		configurer.setTaskExecutor();//设置可重用的线程池，默认是不可重用线程池
    		super.configureAsyncSupport(configurer);
    	}

[70]: /images/20220510/18d981ae97b34c69a0260382351a7e6c.png
[70 1]: /images/20220510/abf2ce41c9774efa96d419cac88d213e.png