Replace direct System.out usage with SLF4J logging (java:S106)

build.gradle

@@ -17,6 +17,11 @@ repositories {
     mavenCentral()
 }
 
+dependencies {
+    implementation 'org.slf4j:slf4j-api:2.0.16'
+    runtimeOnly 'org.slf4j:slf4j-simple:2.0.16'
+}
+
 application {
     mainClass = 'dev.trly.java.example.primitive.wrappers.OrderRollupApp'
 }

src/main/java/dev/trly/java/example/primitive/wrappers/InventoryAuditApp.java

@@ -1,6 +1,11 @@
 package dev.trly.java.example.primitive.wrappers;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public final class InventoryAuditApp {
+    private static final Logger LOGGER = LoggerFactory.getLogger(InventoryAuditApp.class);
+
     private InventoryAuditApp() {
     }
 
@@ -34,15 +39,15 @@ public static void main(String[] args) {
                 totalValue += price;
                 availableCount++;
             }
-            System.out.printf(
-                "Item %d: $%.2f, grade %c, %s%n",
+            LOGGER.info(
+                "Item {}: ${}, grade {}, {}",
                 index + 1,
-                price,
-                grade,
+                String.format("%.2f", price),
+                String.format("%c", grade),
                 available ? "in stock" : "out of stock");
         }
 
-        System.out.printf("Available items: %d worth $%.2f%n", availableCount, totalValue);
+        LOGGER.info("Available items: {} worth ${}", availableCount, String.format("%.2f", totalValue));
     }
 
     public static Double calculateAverageValue(double totalValue, int itemCount) {

src/main/java/dev/trly/java/example/primitive/wrappers/OrderRollupApp.java

@@ -1,6 +1,11 @@
 package dev.trly.java.example.primitive.wrappers;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public final class OrderRollupApp {
+    private static final Logger LOGGER = LoggerFactory.getLogger(OrderRollupApp.class);
+
     private OrderRollupApp() {
     }
 
@@ -25,10 +30,10 @@ public static void main(String[] args) {
             final long cents = orderValues[index].longValue();
             totalBoxes += boxes;
             totalCents += cents;
-            System.out.printf("Order %d: %d boxes, $%.2f%n", index + 1, boxes, cents / 100.0);
+            LOGGER.info("Order {}: {} boxes, ${}", index + 1, boxes, String.format("%.2f", cents / 100.0));
         }
 
-        System.out.printf("Shipped %d boxes for $%.2f%n", totalBoxes, totalCents / 100.0);
+        LOGGER.info("Shipped {} boxes for ${}", totalBoxes, String.format("%.2f", totalCents / 100.0));
     }
 
     public static Integer calculatePackingUnits(int boxesPerOrder, int orderCount) {