In this tutorial, you will learn how to call stored procedures in a Spring Boot RESTful API project that uses Spring Data JPA. Using a stored procedure to execute parts of the application logic in the database is a widely used approach in huge, data-heavy applications. A stored procedure is a group of predefined SQL…
Read More Calling a Stored Procedure in Spring Boot REST with JPAThis tutorial is the fifth in a series on Reactive Programming in Java and Spring Framework. In this tutorial, we will develop a simple REST API using Spring Web flux. To completely understand this tutorial, it is better to read a previous tutorial first. It would also help to know how to develop a REST Controller using…
Read More Developing a REST API using Spring WebFluxIn this tutorial, you will learn how to create a custom password encoder in a Spring Boot application that uses Spring Security. Table of contents Create a Spring Boot project and add database connection properties, Add a User model, Create a User repository, Implement a custom PasswordEncoder, Create a service class that implements UserDetailService, Add…
Read More Custom Password Encoder in Spring SecurityMultiple data source implementations are very crucial in instances where we want to secure the application from vulnerabilities such as a database failure. This will ensure that the application can still function even if part of the database went down. This tutorial will use student and course entities to demonstrate how multiple data sources can…
Read More Multiple Datasources in Spring ApplicationIt will be very difficult for anyone to work with the reactive streams if they neither know how to create nor transform them. It will be clearly impossible to produce any useful program. As you may have guessed, in this tutorial, we will focus on the most common methods provided by Project Reactor to create,…
Read More Important Spring Webflux MethodsThis article is the third of a series on Reactive Programming. If you have not read the previous article, I would strongly advise you to do so. In this article, we will discuss how Reactive Programming is made possible in Spring. Spring WebFlux Spring WebFlux is the Spring project that makes Reactive Programming possible in…
Read More Reactive Programming In Spring FrameworkThis tutorial demonstrates how to deploy a Spring Boot REST app to Tomcat 10. Apache states that the Jakarta EE platform represents the evolution of the Java EE platform. Tomcat 10 and later versions implement specifications that were developed as part of Jakarta EE. In contrast, Tomcat 9 and earlier versions implement specifications that were…
Read More Deploy a Spring Boot App as a WAR to Tomcat 10In this tutorial, you will learn how to use specification and predicate in Spring Data JPA using the Spring Boot RESTful API project. Spring Data JPA Specifications allow us to create dynamic database queries by using the JPA Criteria API. It defines a specification as a predicate over an entity. Spring has a wrapper around…
Read More Specification & Predicate: Advance Search and Filtering in JPAThis tutorial will be part of our Series on Reactive Programming in Java and Spring Framework. If you have not read the previous article, I would strongly advise you to do so. This will help you to understand better as we go further. In the previous blog post, we discussed publishers and subscribers in Java.…
Read More Reactive Programming: Creating Publishers and Subscribers in Java.public sealed class Vehicle permits Car, Truck, Bus {} final class Bus extends Vehicle { } non-sealed class Truck extends Account { } sealed class Car permits BlueCar, RedCar{ } public abstract sealed class User permits PremiumUser, AdvancedUser { public abstract String getUserData(); } non-sealed class PremiumUser extends User { @Override public String getUserData() {…
Read More Sealed Classes and Interfaces in Javaclass Test { public static void main(String[] args) { String name = null; System.out.println(name.toUpperCase()); } } Output: Exception in thread “main” java.lang.NullPointerException at com.example.Test.main (Test.java:9) Here, we got an error message that the NPE has occurred on line 9. Unfortunately, we can’t conclude which value exactly was null from the message. class Test { public static…
Read More Helpful NullPointerExceptions (NPE) in Javaclass Test { public static void main(String[] args) { Vehicle vehicle = new Car(); if (vehicle instanceof Car) { Car car = (Car) vehicle; car.openTrunk(); // other code … } else if (vehicle instanceof Truck) { Truck truck = (Truck) vehicle; truck.removeTrailer(); // other code … } } } class Test { public static void…
Read More Java Pattern Matching for instanceofclass User { private String name; private String username; private String membershipType; private String address; public User(String name, String username, String membershipType, String address) { this.name = name; this.username = username; this.membershipType = membershipType; this.address = address; } public String getName() { return name; } public void setName(String name) { this.name = name; } public…
Read More Java RecordsString multilineText= “”” Hi, this is one simple example of a multiline text”””; class Test { public static void main(String[] args) { String example = “{\”key1\”:\”value1\”,\”key2\”:” + “\”value2\”,\”key3\”:\”value3\”}”; System.out.println(example); } } Output: {“key1″:”value1″,”key2″:”value2″,”key3″:”value3”} Now, let’s use a Text Block: class Test { public static void main(String[] args) { String example = “”” { “key1”:…
Read More Java Text BlocksIn this short article, we will discuss reactive streams in Java. This tutorial is the first of a series on reactive programming in Java and Spring Framework. It will lay down the basis that is required for the following tutorials. I am a big advocate of reactive streams, and I find them fun to program…
Read More Reactive Streams in Java