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26 Items for Dissecting Java Local Variable Type Inference (Var Type)

This article is also part of my book Java Coding Problems.
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The Java Local Variable Type Inference (LVTI), or shortly, the var type (the identifiervaris not a keyword, is a reserved type name), was added in Java 10 via JEP 286: Local-Variable Type Inference. As a 100 percent compile feature, it doesn't affect bytecode, runtime, or performance. Mainly, the compiler will inspect the right-hand side and infer the concrete type. It looks at the right-hand side of the declaration, and if there is an initializer, then it simply uses that type to replacevar. Addtionally, it is useful to reduce verbosity, redundancy, and boilerplate code. It is also meant to speed up the ceremonies involved while writing code. For example, it is very handy to writevar evenAndOdd =...instead of Map <Boolean, List <Integer>> evenAndOdd.... Depending on the use case, it has a trade-off in code readability that is covered in the first item below.

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13 Useful VS Code Extensions for Frontend Development

Visual Studio Code continues to be a widely popular IDE for developers. I started using it two years ago, and in my opinion, it’s a fantastic code editor. It allows me to customize it just the way I want. VS Code also has a build-in git integration and terminal, so you don’t have to jump from one window to another.

There are tones of plugins and even themes, where everyone can find something that he or she needs. The proper setup of VSC can improve our productivity; also, there are some plugins that will help developers to create better, clean code.

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Getting Started With Spring Boot and Spring Data REST

Get started with Spring Boot and Spring Data REST in this short tutorial.

To start working on Spring Data REST, we need to have some basic knowledge of JPA and the Spring Data JPA, as it is built on top of these projects. You can refer to the following links for documentation on Spring Data JPA and Spring Data REST.

You may also like: Introduction to Spring Data REST

Step 1: Add the Following Dependencies to the Project

// Dependency for Spring data jpa
<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
// Dependency for Spring data rest
<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>


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Spring Bean Lifecycle

Spring (Coffee) Bean Lifecycle

The Spring IoC (Inversion of Control) container manages Spring beans. A “Spring bean” is just a Spring-managed instantiation of a Java class.

The Spring IoC container is responsible for instantiating, initializing, and wiring beans. The container also manages the life cycle of beans.

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Stay Hip With the Latest Java and Spring Boot Using JHipster 6

Stay hip with JHipster for your Java and Spring Boot apps

If you’re confused by how OAuth 2.0 and OpenID Connect (OIDC) work together, please see What the Heck is OAuth? In short, OIDC is a thin layer on top of OAuth 2.0 that adds identity.

The Java world has been very busy lately, especially with all the major Java versions releasing every six months. This honestly can be a lot to keep up with. I was using Java 8 until I was introduced to Spring Boot 2.1.

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How Do Annotations Work in Java?

Annotations have been a very important part of Java, and it’s been there from the time of J2SE 5.0. All of us have seen annotations like  @Override and @Deprecated in our application code at some place or another. In this article, I will discuss what exactly annotations are, why they were introduced, how they work, how to write custom annotations (with example code), what could be valid scenarios for annotations, and lastly annotations and ADF. It’s going to be a long post, so grab some coffee and get ready to dive into the world of annotations.

What Are Annotations?

One word to explain annotation is metadata. Metadata is data about data. So annotations are metadata for code. For example, look at the following piece of code.

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A Simple State Machine for Spring Boot Projects

There are many articles and open-source projects on state machines (Ref#1) that can be searched on Google or GitHub. The Spring team itself provides a state machine framework (Ref#2). However, I found these frameworks not easy to customize. Furthermore, it was not easy to add logs and throw custom exceptions where I needed. So I created a simple implementation of the state machine that can be easily integrated into Spring Boot applications. 

The idea of a state machine is to define a set of state transitions where each transition is affected by an event. For instance, Wikipedia has an example for a turnstile that has the Locked and Unlocked states, which are affected by the events "coin" and "push". The turnstile's state transitions from Locked to Unlocked when the "coin" event happens. It transitions from Unlocked to Locked when a "push" event happens. The state machine enforces that when the turnstile is in the Locked state the "push" event has no effect. Similarly, when the turnstile is in the Unlocked state the "coin" event has no effect.

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What Is An API?

If you have a sneaking suspicion that APIs are something you should know about in 2019, you’re onto something! In 2019, APIs are more important than ever, and their prominence in the programming world is only growing. But what exactly...

The post What Is An API? appeared first on Treehouse Blog.

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Secure Your Data Service API Calls

Today, we’re going to take another look at security configurations in Backendless. In this article, we will talk about how to restrict the direct access to your data via API and only expose your custom API endpoints. This does not mean you should use some other set of “admin” APIs for data management. Instead, it is accomplished by setting up proper security settings.

Backendless provides ways to set up really granular permissions for your resources, including even row-level security in your data tables. But for this task, we’re only going to need system roles and global permissions. Thus, it won’t require you to do a lot of configurations or create additional assets, such as custom roles.

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Introduction to the Fluent Builder Pattern

The fluent builder pattern is one of the most useful patterns, especially when you want to build complex objects. For example, say you want to build a complex object by initiating the builder, calling the respective setters, and finally, calling the build method. Once the build method is executed, you will get the desired model/entity/pojo object back.

Email email = Email.EmailBuilder()
              .setFrom("Test@gmail.com")
              .setTo("mail@gmail.com")
              .setSubject("Test with only required Fields")
              .setContent(" Required Field Test").build();


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What Is Code?

Sometimes, it feels like people who can code seem like they have superpowers. But what is code, anyway? Code is all around us. Code is used in things like computers, phones, self-driving cars, and all other...

The post What Is Code? appeared first on Treehouse Blog.