reactor编程如何处理并发远程调用

1、搭建一个简单的webflux工程

pom依赖很简单，就一个，让它去传递依赖去，底层依赖的是4.1.72版本的netty，目前最新是4.1.73了：

<dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-webflux</artifactId>
      <version>2.6.2</version>
    </dependency>
</dependencies>

默认会有很多的debug日志，影响调试观察的话， 可以设置日志logback.xml：

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="60 seconds" debug="false">
    <appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
        <Target>System.out</Target>
        <encoder>
            <pattern>[%d] [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>
    <root level="INFO">
        <appender-ref ref="stdout" />
    </root>
</configuration>

启动类，里面可以根据配置来指定io worker数量，默认会使用runtime去取核数

@SpringBootApplication
public class WebfluxApplication {
    
    public static void main(String[] args) {
        System.setProperty("reactor.netty.ioWorkerCount", "4");
        SpringApplication.run(WebfluxApplication.class, args);
    }
}

2、编写并行调用的controller

    @GetMapping("/zip")
    public Mono<String> zip() {
        Mono<String> mono1 = client.get().uri("abc1").retrieve().bodyToMono(String.class);
        Mono<String> mono2 = client.get().uri("abc2").retrieve().bodyToMono(String.class);
        return Mono.zip(mono1, mono2, User::combine);
    }

public class User {
    static ObjectMapper objectMapper = new ObjectMapper();

    public static String combine(String s1, String s2) {
        try {
            Map<String, String> map1 = objectMapper.readValue(s1, new TypeReference<Map<String, String>>() {
                
            });
            Map<String, String> map2 = objectMapper.readValue(s2, Map.class);
            map1.putAll(map2);
            return objectMapper.writeValueAsString(map1);
        } catch (JsonMappingException e) {
            e.printStackTrace();
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return "test";
    }
    
}

在这里呢， 是同时调用两个接口， 并把两个结果作整合。