add more core java concepts

Author: ImamBiplob

.idea/.gitignore

@@ -0,0 +1,46 @@
+package ComparableAndComparator;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class Book implements Comparable<Book> {
+    private String title;
+    private String author;
+    private int price;
+
+    public String getTitle() {
+        return title;
+    }
+
+    public Book(String title, String author, int price) {
+        this.title = title;
+        this.author = author;
+        this.price = price;
+    }
+
+    @Override
+    public int compareTo(Book o) {
+        return price - (o.price);
+    }
+
+    @Override
+    public String toString() {
+        return "Book{" +
+                "title='" + title + '\'' +
+                '}';
+    }
+
+    public static void main(String[] args) {
+        Book b1 = new Book("Java", "a", 200);
+        Book b2 = new Book("Python", "b", 150);
+        List<Book> booklist = new ArrayList<>();
+        booklist.add(b1);
+        booklist.add(b2);
+        //Collections.sort(booklist);
+        Collections.sort(booklist, new TitleComparator());
+        System.out.println(Collections.binarySearch(booklist, b1));
+
+        System.out.println(booklist);
+    }
+}

.idea/.name

@@ -0,0 +1,10 @@
+package ComparableAndComparator;
+
+import java.util.Comparator;
+
+public class TitleComparator implements Comparator<Book> {
+    @Override
+    public int compare(Book o1, Book o2) {
+        return o1.getTitle().compareTo(o2.getTitle());
+    }
+}

.idea/Java Problems and Solves.iml

@@ -0,0 +1,23 @@
+package DefaultAndStaticMethodsInInterfaces;
+
+public class Truck implements Vehicle {
+    @Override
+    public void start() {
+        System.out.println("Truck has started");
+    }
+
+    @Override
+    public void stop() {
+        System.out.println("Truck has stopped");
+    }
+
+    public static void main(String []args) {
+        Vehicle truck = new Truck();
+
+        truck.start();
+        truck.honk();
+        truck.stop();
+        Vehicle.inspect();
+    }
+}
+

.idea/misc.xml

@@ -0,0 +1,15 @@
+package DefaultAndStaticMethodsInInterfaces;
+
+public interface Vehicle {
+    void start();
+
+    void stop();
+
+    default void honk() {
+        System.out.println("Vehicle Honk!!!");
+    }
+
+    static void inspect() {
+        System.out.println("Vehicle Inspect...");
+    }
+}

.idea/modules.xml

@@ -0,0 +1,6 @@
+package FunctionalInterfaceAndLambdaExpressions;
+
+public interface Calculator {
+    int calculate(int a, int b);
+}
+

.idea/runConfigurations/Java_Problems_and_Solves.xml

@@ -0,0 +1,12 @@
+package FunctionalInterfaceAndLambdaExpressions;
+
+public class Main {
+    public static void main(String[] args) {
+        add(( a, b) -> { return a+b; } ); // Using Lambda Expression
+        add(Integer::sum);                // Using Method Reference
+    }
+
+    public static void add(Calculator calculator) {
+        System.out.println(calculator.calculate(3,2));
+    }
+}

.idea/vcs.xml

@@ -0,0 +1,23 @@
+package MultipleInterfaceImplementation;
+
+public class Duck implements Flyable, Swimmable {
+    public Duck() {
+    }
+
+    @Override
+    public void fly() {
+        System.out.println("Duck is Flying");
+    }
+
+    @Override
+    public void swim() {
+        System.out.println("Duck is Swimming");
+    }
+
+    public static void main(String []args) {
+        Duck duck = new Duck();
+
+        duck.fly();
+        duck.swim();
+    }
+}

More Core Java Concepts to Know/ComparableAndComparator/Book.java

@@ -0,0 +1,5 @@
+package MultipleInterfaceImplementation;
+
+public interface Flyable {
+    void fly();
+}

More Core Java Concepts to Know/ComparableAndComparator/TitleComparator.java

@@ -0,0 +1,5 @@
+package MultipleInterfaceImplementation;
+
+public interface Swimmable {
+    void swim();
+}

More Core Java Concepts to Know/Core Java Questions.txt

@@ -0,0 +1,20 @@
+package UseOfAbstractMethodsInInterfaces;
+
+public class Circle implements Shape {
+    public final double PI = 3.1416;
+    public double radius;
+
+    public Circle(double radius) {
+        this.radius = radius;
+    }
+
+    @Override
+    public double calculateArea() {
+        return PI+radius*radius;
+    }
+
+    @Override
+    public double calculatePerimeter() {
+        return 2*PI*radius;
+    }
+}

More Core Java Concepts to Know/DefaultAndStaticMethodsInInterfaces/Truck.java

@@ -0,0 +1,14 @@
+package UseOfAbstractMethodsInInterfaces;
+
+public class Main {
+    public static void main(String []args) {
+        Shape circle = new Circle(4);
+        Shape square = new Square(2);
+
+        System.out.println(circle.calculatePerimeter());
+        System.out.println(circle.calculateArea());
+
+        System.out.println(square.calculateArea());
+        System.out.println(square.calculatePerimeter());
+    }
+}

More Core Java Concepts to Know/DefaultAndStaticMethodsInInterfaces/Vehicle.java

@@ -0,0 +1,6 @@
+package UseOfAbstractMethodsInInterfaces;
+
+public interface Shape {
+    double calculateArea();
+    double calculatePerimeter();
+}

More Core Java Concepts to Know/FunctionalInterfaceAndLambdaExpressions/Calculator.java

@@ -0,0 +1,19 @@
+package UseOfAbstractMethodsInInterfaces;
+
+public class Square implements Shape {
+    public double side;
+
+    public Square(double side) {
+        this.side = side;
+    }
+
+    @Override
+    public double calculateArea() {
+        return side*side;
+    }
+
+    @Override
+    public double calculatePerimeter() {
+        return 4*side;
+    }
+}

More Core Java Concepts to Know/FunctionalInterfaceAndLambdaExpressions/Main.java

@@ -5,21 +5,20 @@ interface Greeting {
 }
 
 class Task15 {
-    public static void main(String args[]) {
+    public static void main(String []args) {
 
-        Greeting greeting= new Greeting(){
-            public void sayHello(){
+        greet(new Greeting() {                             // Using Anonymous Inner Class
+            @Override
+            public void sayHello() {
                 System.out.println("Hello");
             }
-        };
-//        public void greet(Greeting greeting){
-//            greeting.sayHello();
-//        }
+        });
 
+        greet(() -> System.out.println("hello"));         // Using Lambda expression
 
-        greeting.sayHello();
-
-//        greet(greeting);
+    }
 
+    public static void greet(Greeting greeting){
+        greeting.sayHello();
     }
 }