SparkJava: SLF4J

What is the Simple Logging Framework For Java, and how to configure it

If you work with SparkJava, one of the things you’ll encounter is that it has a dependency on the Simple Logging Framework for Java, also known by its acronym, SLF4J.

This logging framework requires a bit of configuration if:

At the bottom of this article are some pointers to more details. But for now, here is the minimum that you need to know to get SLF4J working for you in the context of a SparkJava project.

Add this to your pom.xml

Near the top:

<properties>
    <slf4jVersion>1.6.1</slf4jVersion>
</properties>

Then, in the dependencies, add this. Swap out slf4j-simple or slf4j-nop depending on which one you want.

  <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>${slf4jVersion}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <!-- use slf4j-simple for System.out, use slfj-nop for no log output -->
      <artifactId>slf4j-simple</artifactId>
      <version>${slf4jVersion}</version>
    </dependency>

A repo that has this code in it, working, is here: https://github.com/pconrad-webapps/sparkjava-hello-improved

References

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