Let’s take a look at exit codes in Spring boot and the various ways we can customize them. What is an Exit Code? In the UNIX shell, An exit code or sometimes known as a return code is a number from 0 to 255 by a process or an executable. These codes let the caller…
Let’s learn all about database initialization in spring boot. We can create and populate a database in different ways. Even though it is common to do this manually, an automatic approach is not a bad thing. For example, Spring Boot offers Schema and Data initialization through the JPA module. We can control this behavior using…
In this post, let’s look at how easy it is to export information from the database to a CSV file using Spring Boot and JPA. For this example, We are going to download data from tables using Spring JPA and write the response as CSV. Approach To demonstrate the export of data into a CSV…
Let’s take a look at reading and writing CSV files in java using OpenCSV with a few examples. First of all, OpenCSV is a CSV file (comma-separated values) parser library for Java. Unlike Apache Commons CSV library, this library is for advanced users who can deal with a little bit of config. Adding OpenCSV to Java…
Let’s take a look at reading and writing CSV files in java using Apache Commons CSV with a few examples. First, you might ask why we need a library when we can write CSV files using pure java. To some extent you are right. However, you would need a library as your custom written reader/writer…
Creating and writing CSV files is easier than you think with Java. CSV stands for Comma Separated Values. As the name suggests, We just need to write values separated by a comma on each line to create such a file. Identify the data you want to write as CSV For example, You have an Array…
Let’s look at how to add WebSocket support to a spring boot application. We will try to create a simple chat application. Note that this implementation does not use STOMP. What is WebSocket? The WebSocket protocol helps establish a full-duplex two-way communication between client and server over a single TCP connection. This protocol is different…
Overview Drools Rule Engine is a Business Rules Management System (BRMS) solution. Some people also consider drool as a Business Logic integration Platform (BLiP). It provides the following features. Core Business Rules Engine (BRE), Drools Workbench (A rule authoring web application) Support for Decision Model and Notation (DMN) Eclipse IDE plugin for core development. Drools has…
In this post, we will take a look at how to troubleshoot auto-configurations in Spring Boot applications. What are Auto-Configurations? Spring boot autoconfiguration is where the magic happens. The auto-configuration tries to automatically configure your application based on what’s in the classpath. For example, the h2 database jar in classpath will result in spring boot…
Spring Boot is an opinionated view of the spring ecosystem and third-party libraries. It helps you to create stand-alone, production-grade Spring-based Applications that you can just run. Spring Boot lets you create Java applications that can run by using java -jar or traditional war deployments. It also provides a command-line tool that runs “spring scripts” with minimum…
