Reactive WebClient on Spring Boot

https://www.baeldung.com/spring-5-webclient

Generic Java Reference https://www.geeksforgeeks.org/generics-in-java/

Unit Testing Reference https://howtodoinjava.com/spring-webflux/webfluxtest-with-webtestclient/

Component scan reference https://www.baeldung.com/spring-nosuchbeandefinitionexception

Factory pattern https://www.geeksforgeeks.org/factory-method-design-pattern-in-java/

If we run use Tomcat Servlet Container, the service implement Tomcat NIO Connector which support Non Blocking / Async. https://dzone.com/articles/understanding-tomcat-nio

By default, webflux run with Netty Servlet Container, Netty implement Java NIO too. https://www.baeldung.com/spring-webflux-concurrency

Java NIO: https://jenkov.com/tutorials/java-nio/index.html

Netty

How to run using Netty Server?

Just exclude the default tomcat server

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-tomcat</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

If we run use Netty Server, and trying to hit endpoint sync (which use block()), will display this error.

    java.lang.IllegalStateException: block()/blockFirst()/blockLast() are blocking, which is not supported in thread reactor-http-nio-3

Netty only support nonblock, if want to run nonblock and block api use tomcat or undertow.

JMeter

How to Run?

    cd apache-jmeter-5.4.3/bin
    sh jmeter.sh