package interfaceExamples; public class IntefaceRules { } interface ExampleInterface1 { // By default - public static final. No other modifier allowed // value1,value2,value3,value4 all are - public static final int value1 = 10; public int value2 = 15; public static int value3 = 20; public static final int value4 = 25; // private int value5 = 10;//COMPILER ERROR // By default - public abstract. No other modifier allowed void method1();// method1 is public and abstract // private void method6();//COMPILER ERROR! public static void m1() {//And we can provide definition for //static method (From java 8 it's possible) System.out.println("Static method"); } //Interface can have a default definition of method. //NEW FEATURE default void method5() { System.out.println("Method5"); } } interface ExampleInterface2 { void method2(); } interface test{ void te(); } // An interface can extend another interface // Class implementing SubInterface1 should // implement method3 and method1(from ExampleInterface1) interface SubInterface1 extends ExampleInterface1 { void method3(); } /* * //COMPILE ERROR IF UnCommented //Interface cannot extend a Class interface * SubInterface2 extends InterfaceRules{ void method3(); } */ /* A Class can implement multiple interfaces */ class SampleImpl implements ExampleInterface1, ExampleInterface2 { /* * A class should implement all the methods in an interface. If either of * method1 or method2 is commented, it would result in compilation error. */ public void method2() { System.out.println("Sample Implementation for Method2"); } public void method1() { System.out.println("Sample Implementation for Method1"); } }