JAVA-27804: Remove explicit logging dependency (#15448)

core-java-modules/core-java-numbers/pom.xml

@@ -14,11 +14,6 @@
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>log4j</groupId>
-            <artifactId>log4j</artifactId>
-            <version>${log4j.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>

core-java-modules/core-java-numbers/src/main/java/com/baeldung/numberofdigits/NumberOfDigitsDriver.java

@@ -1,11 +1,12 @@
 package com.baeldung.numberofdigits;
 
-import org.apache.log4j.Logger;
+
+import java.util.logging.Logger;
 
 public class NumberOfDigitsDriver {
     private static NumberOfDigits numberOfDigits;
 
-    private static Logger LOG = Logger.getLogger(NumberOfDigitsDriver.class);
+    private static Logger LOG = Logger.getLogger(NumberOfDigitsDriver.class.getName());
 
     static {
         numberOfDigits = new NumberOfDigits();