Spring boot 实现高吞吐量异步处理（适用于高并发场景）
技术要点
org.springframework.web.context.request.async.DeferredResult<T>
示例如下：
1. 新建Maven项目 async
2. pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.java</groupId> <artifactId>async</artifactId> <version>1.0.0</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.5.RELEASE</version> </parent> <dependencies> <!-- Spring Boot --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- 热部署 --> <dependency> <groupId>org.springframework</groupId> <artifactId>springloaded</artifactId> <version>1.2.8.RELEASE</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <scope>provided</scope> </dependency> </dependencies> <build> <finalName>${project.artifactId}</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.8</source> <target>1.8</target> <encoding>UTF-8</encoding> </configuration> </plugin> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <executions> <execution> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project>
3. AsyncStarter.java
package com.java; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class AsyncStarter { public static void main(String[] args) { SpringApplication.run(AsyncStarter.class, args); } }
4. AsyncVo.java
package com.java.vo; import org.springframework.web.context.request.async.DeferredResult; /** * 存储异步处理信息 * * @author Logen * * @param <I> 接口输入参数 * @param <O> 接口返回参数 */ public class AsyncVo<I, O> { /** * 请求参数 */ private I params; /** * 响应结果 */ private DeferredResult<O> result; public I getParams() { return params; } public void setParams(I params) { this.params = params; } public DeferredResult<O> getResult() { return result; } public void setResult(DeferredResult<O> result) { this.result = result; } }
5. RequestQueue.java
package com.java.queue; import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue; import org.springframework.stereotype.Component; import com.java.vo.AsyncVo; /** * 存放所有异步处理接口请求队列的对象,一个接口对应一个队列 * * @author Logen * */ @Component public class RequestQueue { /** * 处理下订单接口的队列，设置缓冲容量为50 */ private BlockingQueue<AsyncVo<String, Object>> orderQueue = new LinkedBlockingQueue<>(50); public BlockingQueue<AsyncVo<String, Object>> getOrderQueue() { return orderQueue; } }
6. OrderTask.java
package com.java.task; import java.util.HashMap; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import com.java.queue.RequestQueue; import com.java.vo.AsyncVo; /** * 处理订单接口的任务，每个任务类处理一种接口 * * @author Logen * */ @Component public class OrderTask extends Thread { @Autowired private RequestQueue queue; private boolean running = true; @Override public void run() { while (running) { try { AsyncVo<String, Object> vo = queue.getOrderQueue().take(); System.out.println("[ OrderTask ]开始处理订单"); String params = vo.getParams(); Thread.sleep(3000); Map<String, Object> map = new HashMap<>(); map.put("params", params); map.put("time", System.currentTimeMillis()); vo.getResult().setResult(map); System.out.println("[ OrderTask ]订单处理完成"); } catch (InterruptedException e) { e.printStackTrace(); running = false; } } } public void setRunning(boolean running) { this.running = running; } }
7. QueueListener.java
package com.java.listener; import javax.annotation.PostConstruct; import javax.annotation.PreDestroy; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import com.java.task.OrderTask; /** * 队列监听器，初始化启动所有监听任务 * * @author Logen * */ @Component public class QueueListener { @Autowired private OrderTask orderTask; /** * 初始化时启动监听请求队列 */ @PostConstruct public void init() { orderTask.start(); } /** * 销毁容器时停止监听任务 */ @PreDestroy public void destory() { orderTask.setRunning(false); } }
8. OrderController.java
package com.java.controller; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.context.request.async.DeferredResult; import com.java.queue.RequestQueue; import com.java.vo.AsyncVo; /** * <blockquote> * * <pre> * * 模拟下单处理，实现高吞吐量异步处理请求 * * 1、 Controller层接口只接收请求，不进行处理，而是把请求信息放入到对应该接口的请求队列中 * 2、 该接口对应的任务类监听对应接口的请求队列，从队列中顺序取出请求信息并进行处理 * * 优点：接口几乎在收到请求的同时就已经返回，处理程序在后台异步进行处理，大大提高吞吐量 * * * </pre> * * </blockquote> * * @author Logen * */ @RestController public class OrderController { @Autowired private RequestQueue queue; @GetMapping("/order") public DeferredResult<Object> order(String number) throws InterruptedException { System.out.println("[ OrderController ] 接到下单请求"); System.out.println("当前待处理订单数： " + queue.getOrderQueue().size()); AsyncVo<String, Object> vo = new AsyncVo<>(); DeferredResult<Object> result = new DeferredResult<>(); vo.setParams(number); vo.setResult(result); queue.getOrderQueue().put(vo); System.out.println("[ OrderController ] 返回下单结果"); return result; } }
9. 运行 AsyncStarter.java ，启动测试
浏览器输入 http://localhost:8080/order?number=10001
正常情况处理3秒返回，返回结果如下
{"time":1548241500718,"params":"10001"}
观察控制台打印日志，如下所示：
[ OrderController ] 接到下单请求 当前待处理订单数： 0 [ OrderController ] 返回下单结果 [ OrderTask ]开始处理订单 [ OrderTask ]订单处理完成
结论：Controller层几乎在接收到请求的同时就已经返回，处理程序在后台异步处理任务。
快速多次刷新浏览器，目的为了高并发测试，观察控制台打印信息
现象：Controller层快速返回，待处理请求在队列中开始增加，异步处理程序在按顺序处理请求。
优点：对客户端响应时间不变，但提高了服务端的吞吐量。大大提升高并发处理性能！
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