Java - Medium Articles

Object Pool Design Pattern

Object pool pattern is a software creational design pattern which is used in situations where the cost of initializing a class instance is very high. … Read More

Design Pattern

Java

Misc

System Design

Exception Propagation in Java

Prerequisite : Exceptions in Java, Checked vs Unchecked Exceptions Exception propagation : An exception is first thrown from the top of the stack and if… Read More

Java-Exception Handling

Java-Exceptions

Java

Technical Scripter

Importance of Hashcode method in Java

Prerequisite: Equals() and hashCode() methods in Java HashMap and HashSet use hashing to manipulate data. They use hashCode() method to check hash values. The default… Read More

Java-HashMap

java-hashset

Java

Misc

Java program to read all mobile numbers present in given file

Given the input text file, read all mobile numbers present and write to some output file. Suppose we have a file names as input.txt and… Read More

java-file-handling

Java-I/O

java-regular-expression

Java

Java Programs

Program to check valid mobile number

Mobile Number validation criteria: The first digit should contain numbers between 6 to 9. The rest 9 digit can contain any number between 0 to… Read More

java-regular-expression

Java-String-Programs

Java-Strings

Java

Java 8 Predicate with Examples

A Functional Interface is an Interface which allows only one Abstract method within the Interface scope. There are some predefined functional interface in Java like… Read More

Java

Microsoft Interview Experience | Set 151 (SDE-2 3.5 years experience)

Round 1: Place all numeric characters in string before alphabet characters . Using min swaps and O(1) space and Maintain the order of characters. Round… Read More

Microsoft

Arrays

DSA

Dynamic Programming

Experienced

Experiences

Heap

Interview Experiences

Java

Linked List

Queue

Sorting

Stack

Java.util.Objects class in Java

Java 7 has come up with a new class Objects that have 9 static utility methods for operating on objects. These utilities include null-safe methods… Read More

Java - util package

Java

Misc

Inner reducing pattern printing

Given a number N, print the following pattern. Examples : Input : 4 Output : 4444444 4333334 4322234 4321234 4322234 4333334 4444444 Explanation: (1) Given… Read More

Basic Coding Problems

pattern-printing

DSA

Java

Matrix

Misc

Pattern Searching

How to get a list of files from the FTPserver?

As know FTP is a reliable protocol used for transferring files over the Internet. Though it is not a secure protocol, and all the data… Read More

File Handling

Java-List-Programs

Java

Interrupting a Thread in Java

In Java Threads, if any thread is in sleeping or waiting state (i.e. sleep() or wait() is invoked), calling the interrupt() method on the thread,… Read More

Java-Multithreading

Java

Object level and Class level locks in Java

Synchronization: Synchronization is a modifier that is used for the method and blocks only. With the help of a synchronized modifier, we can restrict a… Read More

Java-Class and Object

Java-Multithreading

Java

Java 8 Optional Class

Every Java Programmer is familiar with NullPointerException. It can crash your code. And it is very hard to avoid it without using too many null… Read More

Java

Check if URL is valid or not in Java

Given a URL as string, we need to find if the given URL is valid or not. Input : str = "https://www.geeksforgeeks.org/" Output : Yes… Read More

java-regular-expression

Java

Misc

Sorting a HashMap according to keys in Java

We are given the details of marks scored by students in form of a HashMap, where the name of the student is the Key and… Read More

Java-Collections

Java-HashMap

Java-Map-Programs

Java

Sorting a 2D Array according to values in any given column in Java

We are given a 2D array of order N X M and a column number K ( 1<=K<=m). Our task is to sort the 2D… Read More

Java-Array-Programs

Java-Arrays

Java

Morgan Stanley Interview Experience | Set 34

Morgan Stanley First Round : Telephonic round I was interviewing for Java developer post at Mumbai office of Morgan Stanley. Interview mostly consisted of multi-threading… Read More

Morgan Stanley

Algorithms

DSA

Experienced

Experiences

Interview Experiences

Java

super and this keywords in Java

In java, super keyword is used to access methods of the parent class while this is used to access methods of the current class. this… Read More

Java

Interesting facts about Array assignment in Java

Prerequisite : Arrays in Java While working with arrays we have to do 3 tasks namely declaration, creation, initialization or Assignment. Declaration of array :… Read More

Interesting-Facts

Java-Array-Programs

Java-Arrays

Java

Java Ternary Operator Puzzle

Find the output of the program Solution: If you run the program,you found that it prints X88. The first print statement prints X and the… Read More

Java-Operators

java-puzzle

Java