added the logs

Java-functional-Interface.iml

@@ -7,5 +7,6 @@
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="slf4j-api-2.0.7" level="project" />
   </component>
 </module>
\ No newline at end of file

src/Lambda/FunctionalInterfaceExample.java

 package Lambda;
 
+
+
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.ArrayList;
 import java.util.List;
 
 public class FunctionalInterfaceExample {
 
+   private static final Logger logger = LoggerFactory.getLogger(FunctionalInterfaceExample.class);
+
     public static void main(String[] args) {
         List<Person> people = new ArrayList<>();
         people.add(new Person("harshitha",1));
@@ -15,7 +23,7 @@ public class FunctionalInterfaceExample {
             return person1.getAge() - person2.getAge();
         });
         for(Person person: people){
-            System.out.println(person.getName()+ " " +person.getAge());
+           logger.info(person.getName()+ " " +person.getAge());
         }
 
     }

src/Lambda/FunctionalTest.java

 package Lambda;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public interface FunctionalTest {
 
+    static final Logger logger = LoggerFactory.getLogger(FunctionalInterfaceExample.class);
+
     void abstractTest(int x);
 
     default void Message(){
-        System.out.println("hello");
+        logger.info("hello");
     }
 
 }

src/Lambda/PredicateExample.java

 package Lambda;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public class PredicateExample {
+
+    private static final Logger logger = LoggerFactory.getLogger(FunctionalInterfaceExample.class);
     public static void main(String[] args) {
         Display i = () -> System.out.println("This is predicate example");
         i.hello();
 
-        SumOfTwoIntegers s = (a, b) -> (a+b);
-        System.out.println(s.sum(5,6));
-        System.out.println(s.sum(7,7));
+        SumOfTwoIntegers s = (a, b) -> String.valueOf((a+b));
+        logger.info(s.sum(5,6));
+        logger.info(s.sum(7,7));
     }
 }

src/Lambda/PredicateExample1.java

 package Lambda;
 
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.*;
@@ -8,6 +11,8 @@ import java.util.function.Predicate;
 
 public class PredicateExample1 {
 
+    private static final Logger logger = LoggerFactory.getLogger(FunctionalInterfaceExample.class);
+
     public static void main(String[] args) {
         List<User> users = new ArrayList<User>();
         users.add(new User("dev","Harshitha"));
@@ -15,7 +20,7 @@ public class PredicateExample1 {
         users.add(new User("QA","Anusha"));
 
         List devs = process(users,(User u)->u.getRole().equals("dev"));
-        System.out.println(devs);
+        logger.info(devs.toString());
 
     }
 

src/Lambda/PredicateStringComparing.java

 package Lambda;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.function.Predicate;
 
 public class PredicateStringComparing {
+
+    private static final Logger logger = LoggerFactory.getLogger(FunctionalInterfaceExample.class);
     public static void main(String[] args) {
         String s1="hello";
         String s2="hello";
         Predicate<String> p = s->s.equals(s2);
 
         if(p.test(s1)){
-            System.out.println("equal");
+            logger.info("equal");
         }
         else{
-            System.out.println("not equal");
+            logger.info("not equal");
         }
 
     }

src/Lambda/SumOfTwoIntegers.java

@@ -3,5 +3,5 @@ package Lambda;
 public interface SumOfTwoIntegers
 {
 
-    public abstract int sum(int a,int b);
+    public abstract String sum(int a, int b);
 }

src/Lambda/SupplierExample.java

 package Lambda;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
 public class SupplierExample {
-    public static void main(String[] args) {
 
+    private static final Logger logger = LoggerFactory.getLogger(FunctionalInterfaceExample.class);
+    public static void main(String[] args) {
 
         //example of supplier
         Supplier<String> supplier = () -> {
-            System.out.println("inside the supplier");
+            logger.info("inside the supplier");
             return  "hello";
         };
         String string = supplier.get();
-        System.out.println(string);
+        logger.info(string);
 
 
         //example of consumer
         Consumer<String> consumer = (String s) -> {
-            System.out.println("Inside the consumer");
-            System.out.println(s);
+           logger.info("Inside the consumer");
+            logger.info(s);
         };
         consumer.accept("hello");
 
         Supplier<String> supplier1 = () -> {
-            System.out.println("Supplier");
+            logger.info("Supplier");
             return "hello";
         };
         String s = supplier1.get();
-        System.out.println(s);
+        logger.info(s);
     }
 }