functional interface java

1// interface in java example
2interface Vehicle
3{
4   public void accelerate();
5}
6class BMW implements Vehicle
7{
8   public void accelerate()
9   {
10      System.out.println("BMW accelerating...");
11   }
12}
13public class InterfaceDemo
14{
15   public static void main(String[] args)
16   {
17      BMW obj = new BMW();
18      obj.accelerate();
19   }
20}

1interface methods{
2 public static hey(); 
3}
4
5class scratch implements methods{
6  // Required to implement all methods declared in an interface 
7  // Or else the class becomes abstract
8  public static hey(){
9   System.out.println("Hey"); 
10  }
11}

1/* File name : MammalInt.java */
2public class MammalInt implements Animal {
3
4   public void eat() {
5      System.out.println("Mammal eats");
6   }
7
8   public void travel() {
9      System.out.println("Mammal travels");
10   } 
11
12   public int noOfLegs() {
13      return 0;
14   }
15
16   public static void main(String args[]) {
17      MammalInt m = new MammalInt();
18      m.eat();
19      m.travel();
20   }
21} 

1Interfaces specify what a class must do. 
2It is the blueprint of the class.
3It is used to achieve total abstraction. 
4We are using implements keyword for interface.
5
6Basic statement we all know in Selenium is
7WebDriver driver = new FirefoxDriver();
8WebDriver itself is an Interface.
9So we are initializing Firefox browser
10using Selenium WebDriver.
11It means we are creating a reference variable
12of the interface and creating an Object.
13So WebDriver is an Interface and
14FirefoxDriver is a class.
15
16

1public interface Exampleinterface {
2	
3  public void menthod1();
4  
5  public int method2();
6
7}
8
9class ExampleInterfaceImpl implements ExampleInterface {
10
11
12  	public void method1()
13    {
14        //code here
15    }
16  
17    public int method2()
18  	{
19    	//code here
20  	}
21
22}

1A functional interface is an interface that contains only one abstract method. They can have only one functionality to exhibit.