write program fibonacci series, write program using boolean, write class cast exceptn, singleton design pattern(like you have to jvm one have jdk 1.7 and other have jdk 1.8 how many instance created if one then how and more than two then how we convert them to one, explain abstract clss and interface in your current project explain hassing in hash map how many bucket fail fast fale safe how you handle exception in sping spring bean life cycle write a program for generics

Question

Accepted Answer

This interview question covers various topics including programming, design patterns, data structures, and exception handling in Java.

Write a program to generate the Fibonacci series
Write a program using boolean variables
Explain the ClassCastException and how to handle it
Discuss the Singleton design pattern and its implementation with different JDK versions
Explain abstract classes and interfaces in your current project
Explain hashing in HashMap and the number of buckets
Differentiate between fail-fast and fail-safe in Java
Explain how you handle exceptions in Spring
Discuss the Spring bean lifecycle
Write a program using generics

Accepted Answer

package com.devdaily.javasamples;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class ClassCastExceptionExample {

    public ClassCastExceptionExample() {

        List list = new ArrayList();
        list.add("one");
    
        // ... some time later
    
        Iterator it = list.iterator();
        while (it.hasNext()) {
            // intentionally throw a ClassCastException by trying to cast a String to an
            // Integer (technically this is casting an Object to an Integer, where the Object 
            // is really a reference to a String:
            Integer i = (Integer)it.next();
      }

  }

  public static void main(String[] args) {
      new ClassCastExceptionExample();
  }

}

Accepted Answer

public class BooleanExample1 {
public static void main(String[] args) {
int num1=10;
int num2=20;
boolean b1=true;
boolean b2=false;
if(num1
{
System.out.println(b1);
}
else
{
System.out.println(b2);
}

Accepted Answer

class FibonacciExample1{
public static void main(String args[])
{
int n1=0,n2=1,n3,i,count=10;
System.out.print(n1+" "+n2);//printing 0 and 1
for(i=2;i//loop starts from 2 because 0 and 1 are already printed
{
n3=n1+n2;
System.out.print(" "+n3);
n1=n2;
n2=n3;
}
}}

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