Java

Java 11: Lambda Expression and String functions

Reading Time: 3 minutes Java 11 comes up with a lot of new features, thus easing out the life of a programmer. In this blog, I will discuss some of them. First and foremost great news about java 11, we need not to compile the java source file using command javac. A java program can now easily run using java command as the compilation happens implicitly. Lambda Parameter Syntax: Continue Reading

Querying Array of String using JPA Specification

Reading Time: 2 minutes Writing dynamic queries using JPA Specification could be a hard to understand and implement but lets make it simple and easy to understand! To query array of string in postgreSQL , we might use a query like this : select * from employee where ARRAY_TO_STRING(keywords, ‘,’) LIKE ‘%lunch%’; To use specification for querying array string datatype ,we will have to Define a custom dialect to Continue Reading

Flink: Join two Data Streams

Reading Time: 3 minutes Apache Flink offers rich sources of API and operators which makes Flink application developers productive in terms of dealing with the multiple data streams. Flink provides many multi streams operations like Union, Join, and so on. In this blog, we will explore the Window Join operator in Flink with an example. It joins two data streams on a given key and a common window. Let say we have one stream which contains salary information of all Continue Reading

How to set default column value in JPA

Reading Time: < 1 minute There might be a situation when you want to set the default value of column in spring boot. You might be thinking how to set it even when you have set the default value in the database but you still get a null value stored in the database . It is because JPA includes the columns with null value in the insert query which you Continue Reading

Understanding Java enums

A Guide to Method References in Java 8

Reading Time: 2 minutes In this blog, we will get to know about method references in Java, where and how to use them. What are Method References? Method References allow us to pass the name of a method where a functional interface is expected. This brings us to another question. What is a Functional Interface? Functional Interfaces are single-method interfaces that encapsulate a single behaviour. For eg. Runnable which Continue Reading

Java8 Futures: Introduction & Best Practices

Reading Time: 3 minutes Hi there! Today, we are going to talk about Futures in Java. We will also look at some of the best practices related to them. What are Java Futures and why do we need them? To understand this better, firstly we must understand what is blocking and why is it bad for our software. BLOCKING – A blocking/long-running call occurs when a thread is tied Continue Reading

Beginner’s Guide to GraphQL with Spring Boot

Reading Time: 4 minutes The world is a stage where all of us are artists. Constant learning is the foundation of success. So here we are going to have a tutorial on GraphQL in which we will see how to create a GraphQL server in Java. Objective We are going to query the details for a specific song from an online platform. Prerequisite Basic knowledge of:– Spring Boot– Java– Continue Reading

Resilience4j Retry with SpringBoot

Reading Time: 2 minutes Hi guys, I hope you are doing good. In this blog, we will be talking about one of the core modules of resilience4j: Retry. If you are not familiar with the resilience4j library then you can refer my last blog Bulkhead with Resilience4j. It would be a 2 minutes read. What is Retry in API calls? We use the Retry mechanism to make out the micro-services Continue Reading

Spring Beans in Java

Reading Time: 2 minutes Spring IoC container is the core of the Spring Framework.In spring-based applications, objects live inside a spring containerThe container instantiate the objects, wires them together and manages their complete life cycle from creation till destruction.These objects in the Spring IoC container are referred to as beans. What is Inversion Of Control(IoC)? IoC simply means giving control to spring container to create and instantiate the spring beans Let`s say you want to Continue Reading