Graal uses SLF4J as logging API. If SLF4J does not find any implementation of its API, it prints the following warning message:
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.
To disable this warning, you need to bind (in the java classpath) an implementation of this library and configure it correctly. In the next paragraph, we show how bind and configure logback to disable all logging.
Logback is an implementation of SLF4J, you can bind it to your code as follows:
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.3</version>
</dependency>
By default, logback will print all log messages on the standard output. To disable this behavior, you must add a logback configuration file called logback.xml in your java classpath root. You can download this minimal logback.xml file and add it in the src/main/resources directory for a maven project or beside fr directory for a simple java project. See the logback confguration page for more details.