core java

Software Development Engineer - Automation Testing

Apply Now Salary: Competitive Address: 52 Út Tịch, Phường 4, Quận Tân Bình, TP. Hồ Chí Minh See map Posted: 30-11-2019 Expired: 31-12-2019 Job Description ...

Top 400 Java Interview Questions and Answers

[Complete Java] Notes and Programs for Fundamental & Important Concepts of Java Programming & Development.

Suryakant-Bharti/Important-Java-Concepts [Complete Java] Notes and Programs for Fundamental & Important Concepts of Java Programming & Development. Users starred: 47Users...

Find the Smallest Missing Integer in an Array

1. Overview In this tutorial, we'll see different algorithms allowing us to find the smallest missing positive integer in an array. First, we'll go through the explanation of the...

Causes & Avoidance of java.lang.VerifyError

1. Introduction In this tutorial, we'll look at the cause of java.lang.VerifyError errors and multiple ways to avoid it. 2. Cause The Java Virtual Machine (JVM) distrusts all...

Converting Java Date to OffsetDateTime

1. Introduction In this tutorial, we learn about the difference between Date and OffsetDateTime. We also learn how to convert from one to the other. 2. Difference between Date...

Java ‘protected’ Access Modifier

1. Overview In the Java programming language, fields, constructors, methods, and classes can be marked with access modifiers. In this tutorial, we'll look at protected access. 2....

Adding an Element to a Java Array vs an ArrayList

1. Overview In this tutorial, we'll briefly look at the similarities and dissimilarities in memory allocation between Java arrays and ArrayList. Furthermore, we'll see how to...

The 2019 Java Developer RoadMap

I have been sharing a lot of roadmaps to become a Web developer, DevOps engineer, and recently React.js developer. One of the requests I received from many of my readers was for...

Searching for a String in an ArrayList

1. Overview In this tutorial, we'll look into different ways to search for a String in an ArrayList. Our intent is to check if a specific non-empty sequence of characters is...

Java isNumeric method

In this post, we will see how to implement isNumeric method in java. There are many way to check if String is numeric or not. Let’s see one by one. Using regular expressions You can use below regular expression to check if string is numeric or not. [-+]?\\d*\\.?\\d+ package org.arpit.java2blog; public class JavaisNumericMain { public static void main(String...

Fix cannot make static reference to non-static method

In this post, we will see how to solve cannot make static reference to non-static method. Let’s understand this error with the help of example. package...

Implement distance formula in java

In this post, we will see how to implement distance formula between two points in java. Formula to find distance between two points ( x1, y1) and (x2 , y2) is Source:...

Convert decimal to binary in java

In this post, we will see how to convert decimal to binary in java. There are lot of ways to convert decimal to binary in java.Let’s explore them one by one. Using Integer.toBinaryString() method You can simply use inbuilt Integer.toBinaryString() method to convert a decimalpackage org.arpit.java2blog; public class DecimalToBinaryInBuiltMain { public static void main(String[] args)...

Calculate total surface area of Cylinder in java

In this post, we will see how to calculate total surface area of Cylinder in java. Formula of calculating total surface area of Cylinder is: Surface area of Cylinder = 2 *Π * r *...

Print prime numbers from 1 to 100 in java

In this program, we will print prime numbers from 1 to 100 in java. A prime number is a number which has only two divisors 1 and itself. To check if the number is prime or not, we need to see if it has any other factors other than 1 or itself. If it has, then number is not prime else number is prime. Algorithm Iterate from 1 to 100. In each iteration, check is number is prime or not. If number...

Methods in Java

1. Introduction In Java, methods are where we define the business logic of an application. They define the interactions among the data enclosed in an object. In this tutorial,...

Comparing Dates in Java

1. Introduction In this tutorial, we'll focus on how to compare dates using the Java 8 Date/Time API. We'll dive into different methods to check whether two dates are equal and...

Is "Java Concurrency in Practice" Still Valid in the Era of Java 8 and 13?

One of my reader Shobhit asked this question on my blog post about 12 must-reads advanced Java books for intermediate programmers - part1. I really like the question and thought...

How to avoid deadlock in Java?

How to avoid deadlock in Java? Is one of the popular Java interview question and flavor of the season for multi-threading, asked mostly at a senior level with lots of follow up...

What is Xms and Xmx parameter in java?

In this post, we will see about Xms and Xmx parameter in java. -Xmx specifies maximum memory size for Java virtual machine (JVM), while -Xms specifies the initial memory size. It means JVM will be started with Xms amount of memory and JVM will be able to use maximum of JVM amount of memory. Let’s understand this with help of example. java -Xms512m -Xmx1024m So java process will start with 512...