JAVA-18116 Review log statements for projects - Week 7 - 2023 (#13583)

JAVA-18116 Review log statements for projects - Week 7 - 2023 (#13583)
---------

Co-authored-by: jogra <joseph.sterling.grah@miles.no>

core-java-modules/core-java-concurrency-advanced/src/main/java/com/baeldung/concurrent/countdownlatch/Worker.java

@@ -1,9 +1,14 @@
 package com.baeldung.concurrent.countdownlatch;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 
 public class Worker implements Runnable {
+
+    private static Logger log = LoggerFactory.getLogger(Worker.class);
     private final List<String> outputScraper;
     private final CountDownLatch countDownLatch;
 
@@ -15,7 +20,7 @@ public class Worker implements Runnable {
     @Override
     public void run() {
         // Do some work
-        System.out.println("Doing some logic");
+        log.debug("Doing some logic");
         outputScraper.add("Counted down");
         countDownLatch.countDown();
     }

core-java-modules/core-java-concurrency-advanced/src/main/java/com/baeldung/concurrent/phaser/LongRunningAction.java

@@ -1,8 +1,13 @@
 package com.baeldung.concurrent.phaser;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.concurrent.Phaser;
 
 class LongRunningAction implements Runnable {
+
+    private static Logger log = LoggerFactory.getLogger(LongRunningAction.class);
     private String threadName;
     private Phaser ph;
 
@@ -14,18 +19,18 @@ class LongRunningAction implements Runnable {
 
     @Override
     public void run() {
-        System.out.println("This is phase " + ph.getPhase());
-        System.out.println("Thread " + threadName + " before long running action");
+        log.info("This is phase {}", ph.getPhase());
+        log.info("Thread {} before long running action", threadName);
         
         try {
             Thread.sleep(2000);
         } catch (InterruptedException e) {
             e.printStackTrace();
         }
-        
-        System.out.println("Thread " + threadName + " action completed and waiting for others");
+
+        log.debug("Thread {} action completed and waiting for others", threadName);
         ph.arriveAndAwaitAdvance();
-        System.out.println("Thread " + threadName + " proceeding in phase " + ph.getPhase());
+        log.debug("Thread {} proceeding in phase {}", threadName, ph.getPhase());
         
         ph.arriveAndDeregister();
     }