<dependency>
  <groupId>org.apache.logging.log4j</groupId>
  <artifactId>log4j-slf4j-impl</artifactId>
   <version>2.10.0</version>
 </dependency>

 <dependency>
   <groupId>ch.qos.logback</groupId>
   <artifactId>logback-classic</artifactId>
  <version>1.2.3</version>
</dependency>
pom.xml

class
protected Logger logger = LoggerFactory.getLogger(WebSocketChatClient.class.getName());

log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="INFO">
 <Appenders>
  <Console name="console" target="SYSTEM_OUT">
   <PatternLayout
    pattern="[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n" />
  </Console>
 </Appenders>
 <Loggers>

  <Root level="debug" additivity="false">
   <AppenderRef ref="console" />
  </Root>
 </Loggers>
</Configuration>