Spring Boot集成Reactor事件处理框架的简单示例

1. Reactor简介

Reactor 是 Spring 社区发布的基于事件驱动的异步框架，不仅解耦了程序之间的强调用关系，而且有效提升了系统的多线程并发处理能力。

2. Spring Boot集成Reactor的pom.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <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>org.springframework</groupId>
     <artifactId>spring-boot-reactor</artifactId>
     <version>0.1.0</version>

     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>0.5.0.M2</version>
     </parent>

     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter</artifactId>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
         <dependency>
             <groupId>org.projectreactor</groupId>
             <artifactId>reactor-spring</artifactId>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-web</artifactId>
         </dependency>
     </dependencies>

     <properties>
         <start-class>org.springboot.reactor.example.App</start-class>
     </properties>

     <build>
         <plugins>
             <plugin>
                 <artifactId>maven-compiler-plugin</artifactId>
             </plugin>
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
             </plugin>
         </plugins>
     </build>

     <repositories>
         <repository>
             <id>spring-snapshots2</id>
             <url>http://repo.springsource.org/libs-snapshot</url>
             <snapshots>
                 <enabled>true</enabled>
             </snapshots>
         </repository>
         <repository>
             <id>spring-release</id>
             <url>http://repo.springsource.org/libs-release</url>
             <snapshots>
                 <enabled>false</enabled>
             </snapshots>
         </repository>
     </repositories>
     <pluginRepositories>
         <pluginRepository>
             <id>spring-snapshots</id>
             <url>http://repo.springsource.org/libs-snapshot</url>
             <snapshots>
                 <enabled>true</enabled>
             </snapshots>
         </pluginRepository>
     </pluginRepositories>
 </project>

3. Spring Boot的主程序

 package org.springboot.reactor.example;

 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;

 @Configuration
 @EnableAutoConfiguration
 @ComponentScan
 public class App{
     public static void main( String[] args ) {
     	SpringApplication.run(App.class, args);
     }
 }

4. 领域数据User

 package org.springboot.reactor.example;

 public class User {

 	String firstName;

 	String lastName;

 	String address;

 	String city;

 }
 

5. 实例化Reactor Bean,这里采用内部 Bean 方式实现，其他方式也可以，保证能够供其它类注入即可

 package org.springboot.reactor.example;

 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;

 import reactor.core.Environment;
 import reactor.core.Reactor;
 import reactor.core.spec.Reactors;

 @Configuration
 public class Configure {
 	@Bean
 	Environment env() {
 		return new Environment();
 	}

 	@Bean
     Reactor createReactor(Environment env) {
         return Reactors.reactor()
                 .env(env)
                 .dispatcher(Environment.THREAD_POOL)
                 .get();
     }
 }

6. Controller层用于通过reactor.notify发送事件

 package org.springboot.reactor.example;

 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;

 import reactor.core.Reactor;
 import reactor.event.Event;

 @RestController
 @RequestMapping("/api")
 public class ReactorController {

 	@Autowired
 	private Reactor reactor;

 	@RequestMapping("/test")
 	public void test() throws InterruptedException{
 		User user = new User();
 		user.firstName = "Chetan";
 		user.lastName = "Birajdar";
 		user.address = "410 S Hauser";
 		user.city = "Los Angeles";
 		reactor.notify("eventHandler", Event.wrap(user));
 		System.out.println("y0, I sent something for you!!");
 	}
 }
 

7. 事件的监听器，以便于接收发送的事件并处理。需要实现 Consumer<Event<T>> 接口，其中 T 是处理程序接收的数据类型，要根据具体业务设置

 package org.springboot.reactor.example;

 import org.springframework.stereotype.Service;

 import reactor.event.Event;
 import reactor.function.Consumer;

 @Service
 public class AppListener implements Consumer<Event<User>>{

 	public void accept(Event<User> event) {
 		System.out.println("Received user object with "
 				+ "first name:"
 				+ event.getData().firstName
 				+ ", last name:"
 				+ event.getData().lastName
 				+ ", address:"
 				+ event.getData().address
 				+ ", city:"
 				+ event.getData().city
 				+ "");
 	}
 }
 

8. ReactorService，实现InitializingBean接口，以便将发送的事件绑定到指定的监听器

 package org.springboot.reactor.example;

 import static reactor.event.selector.Selectors.$;

 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;

 import reactor.core.Reactor;

 @Service
 public class ReactorService implements InitializingBean{

 	@Autowired
 	private Reactor reactor;

 	@Autowired
 	private AppListener appListener;

 	@Override
 	public void afterPropertiesSet() throws Exception {
 		reactor.on($("eventHandler"), appListener);
 	}
 }

9. 当启动应用时，调用/api/test接口，向eventHandler的topic发送User事件，监听器即可接收到相关的事件并处理