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Multilevel Inheritance in java with public variables and parameterized Constructor

This is a demonstration of Multi-level inheritance in java using parameterised constructor package com.inheritance; public class Class1 { public int a; public int b; public Class1(int a, int b) { super(); this.a = a; this.b = b; System.out.println("I am super class called first--->"+(a+b)); System.out.println(a+b); } } --------------------------------------------- package com.inheritance; public class Class2 extends Class1 { public int c; public Class2(int a, int b, int c) { super(a, b); this.c=c; System.out.println("I am the second level subclass--->" +a%c); } } -------------------------------------------------------------- package com.inheritance; public class Class3 extends Class2 { public int d; public Class3(int a, int b,int c, int d) { super(a, b, c); this.d=d; System.out.println("I am thrid level subclass extends second level class-->"+a*b*c*d); //

Can a Class implement two interfaces with the same method signature

I created two interfaces with same method signature. You can actually implement the method only once. package com.anjana; public interface Interface2 { public String printme(); } package com.anjana; public interface Interface1 { public String printme(); } package com.anjana; public class Employee implements Interface1,Interface2,Interface3{ @Override public String printme() { return "Hello"; } public static void main(String args[]){ Interface1 emp1=new Employee(); emp1.printme(); System.out.println(emp1.printme()); Interface2 emp2=new Employee(); System.out.println(emp2.printme()); } This will be misleading if you have to do some operations based on the returned value.

Example:Immutable Class

Immutable class is thread safe Imuutable class objects cannot be modified Examples : Integer String package com.demo.immutable; //make ur class final public final class MyImmutable {  //make ur instance variables final     final String s="Anjana";     private String s2=null; //access the private via constructors--to modify     public MyImmutable(String s2) {         super();         this.s2 = s2;     }     public static void main(String args[]){         MyImmutable  myimmutable=new MyImmutable("dff");     } }