Uses io.socket:socket.io-client 2.1.1, which speaks Engine.IO v4 out of the box.
Gradle
dependencies {
implementation 'io.socket:socket.io-client:2.1.1'
}Maven
<dependency>
<groupId>io.socket</groupId>
<artifactId>socket.io-client</artifactId>
<version>2.1.1</version>
</dependency>Run with LIVERATES_KEY=trial java Client.