 <p>Restlet uses JDK's logging API that you can bridge to log4j.</p> <p>Your own classes can use the SLF4J API, if you prefer (I prefer the logj4 API though), which also can bridge to log4j.</p> <p>You'll need two bridges in the runtime classpath: log4j-jul e log4j-slf4j-impl.</p> <p>In Maven, do:</p> <pre><code>&lt;dependency&gt; &lt;groupId&gt;org.apache.logging.log4j&lt;/groupId&gt; &lt;artifactId&gt;log4j-jul&lt;/artifactId&gt; &lt;version&gt;2.2&lt;/version&gt; &lt;scope&gt;runtime&lt;/scope&gt; &lt;/dependency&gt; &lt;dependency&gt; &lt;groupId&gt;org.apache.logging.log4j&lt;/groupId&gt; &lt;artifactId&gt;log4j-slf4j-impl&lt;/artifactId&gt; &lt;version&gt;2.2&lt;/version&gt; &lt;scope&gt;runtime&lt;/scope&gt; &lt;/dependency&gt; </code></pre> <p>That way, you can configure both using Log4j.</p>