Logging

You can use any logging framework of your choice with Twitch4J, but you have to add at least one so that logging works correctly.

If you do not add at least one, you will see the following output:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

Here are a few examples on how to add a logging library of your choice:

Library: Logback

Gradle - Groovy

dependencies {
    implementation group: 'ch.qos.logback', name: 'logback-classic', version: '1.3.5'
}

Gradle - Kotlin DSL

dependencies {
    implementation(group = "ch.qos.logback", name = "logback-classic", version = "1.3.5")
}

Maven

<dependencies>
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.3.5</version>
    </dependency>
</dependencies>

And place a configuration file logback.xml into src/main/resources. This is the place you can use to configure logging:

<?xml version="1.0" encoding="UTF-8"?>

<configuration scan="true">
	<!-- Configure Twitch4J logger level -->
	<logger name="com.github.twitch4j" level="INFO"/>

	<!-- Appender Configuration [Console] -->
	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
		<encoder>
			<pattern>%d{HH:mm:ss.SSS} [%thread] %highlight([%-5level]) %logger{25} - %msg%n</pattern>
		</encoder>
	</appender>

	<!-- Appender Configuration [File] -->
	<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
		<encoder>
			<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
		</encoder>
		<file>client.log</file>
		<rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
			<fileNamePattern>client.%i.log</fileNamePattern>
		</rollingPolicy>
		<triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
			<MaxFileSize>10MB</MaxFileSize>
		</triggeringPolicy>
	</appender>

	<!-- Appender Output Configuration -->
	<root level="info">
		<appender-ref ref="CONSOLE"/>
	</root>
</configuration>

This sample only logs to the console, you can change the appender-ref from CONSOLE to FILE to use file-based logging with rotation - refer to the logback documentation for further customization options.