Java Series Part 7: Creating Multiplication Table using Classes, Object and Methods

Create a class called Multiplication table as below: Ch7MultiplicationTable.java package com.java.basic; public class Ch7MultiplicationTable { void print() { for(int i=1; i<=10;i++) { System.out.printf("%d * %d = %d", 5, i, 5*i).println(); } } // making it generic to accept parameters that is print table of any number void print(int n) { for(int i=1; i<=10;i++) { System.out.printf("%d … Continue reading Java Series Part 7: Creating Multiplication Table using Classes, Object and Methods →

Java Series Part 6 – Classes, Objects and Methods

A method is a block of code which only runs when it is called. You can pass data, known as parameters, into a method. Methods are used to perform certain actions, and they are also known as functions. Java is an object-oriented programming language. Everything in Java is associated with classes and objects, along with its attributes and … Continue reading Java Series Part 6 – Classes, Objects and Methods →

Java Series Part 5 – JVM, JRE and ByteCode

JVM, JRE and JDK JVM (Java Virtual Machine) is an abstract machine. It is called a virtual machine because it doesn't physically exist. It is a specification that provides a runtime environment in which Java bytecode can be executed. It can also run those programs which are written in other languages and compiled to Java … Continue reading Java Series Part 5 – JVM, JRE and ByteCode →

Java Series Part 4 – Strings & String Concatenation

Strings are used for storing text. A String variable contains a collection of characters surrounded by double quotes: String greeting = "Hello"; A String in Java is actually an object, which contain methods that can perform certain operations on strings. For example, the length of a string can be found with the length() method: String txt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; System.out.println("The … Continue reading Java Series Part 4 – Strings & String Concatenation →

Java Series Part 3 – Variable/Data Types

Primitive Data Types Data types that can store integer values: int i;byte b;short s;long l; Variable types: byte b = 5; //8bits - 128 to 127short s = 128 //16bits - 32,768 to 32,767int i = 40000; //32 bits - 2,147,483,648 to 2,147,483,647long l = 222222222; //64bits -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807float f = 4.0f; //32 bits … Continue reading Java Series Part 3 – Variable/Data Types →

Java Series Part 2: Java Variables

Variables in Java are containers for storing data values. In Java, there are different types of variables, for example: String - stores text, such as "Hello World". String values are surrounded by double quotes int - stores integers (whole numbers), without decimals, such as 15 or -15 float - stores floating point numbers, with decimals, such as 1.99 or -1.99 … Continue reading Java Series Part 2: Java Variables →

Java Series Part 1: Java Expressions

A Java expression consists of variables, operators, literals, and method calls. package com.java.basic; public class ExpressionsExample { public static void main(String args[]) { // 5 + 2 is an expression int add = 5 + 2; System.out.println("Addition= " + add); // 5 - 2 is an expression int sub = 5 - 2; System.out.println("Substraction= " + … Continue reading Java Series Part 1: Java Expressions →

My experience as AWS Community builder for 2021

Is it one year already? Wow time was delivered as fast as CloudFront deliver content 😊 Around this time last year, I was doubting myself about applying for the Community Builders program. I did some research before applying to give me some comfort. I discovered that the number of applications was huge but that was not … Continue reading My experience as AWS Community builder for 2021 →

Cannot access Spring boot app from Docker host and port after deploying to Docker Containers. Solved!

I recently faced an issue where I deployed our spring boot application Docker environment. Everything worked our perfectly fine like app was getting started in docker env. as per logs. But when we tried to access the app endpoints from the docker host and port or the load balancer it was the container was unreachable. … Continue reading Cannot access Spring boot app from Docker host and port after deploying to Docker Containers. Solved! →

Error: kie.container or kieModule bean – Null Pointer Exception? Solved!

I recently we faced an issue in my Drools Config class where we added config for kie container and kie modules. It was working fine in normal windows server environment but we migrated our app into docker environment we faced below error. When running our Java Spring Boot app (Fat Jar) on Docker Environment we … Continue reading Error: kie.container or kieModule bean – Null Pointer Exception? Solved! →