Joseph  Murray

Joseph Murray

1622592960

Java Feature Spotlight: Pattern Matching

Key Takeaways

  • Java SE 14 (March 2020) introduced a limited form of pattern matching as a preview feature, which becomes a permanent feature in Java SE 16 (March 2021).
  • The first phase of pattern matching is limited to one kind of pattern (type patterns) and one language construct (instanceof), but this is only the first installment in a longer feature arc.
  • At the simplest level, pattern matching allows us to reduce the ceremony of conditional state extraction, where we ask a question about some object (such as “are you a Foo”), and, if the answer is positive, we extract some state from the target: e.g. “if (x instanceof Integer i) { … }” where i is the binding variable
  • Binding variables are subject to definite assignment, but take this one step further: the scope of a binding variable is the set of places in the program where it would be definitely assigned. This is called flow scoping.
  • Pattern matching is a rich feature arc that will play out over several Java versions. Future installments will bring us patterns in switch, deconstruction patterns on records, and more, with the aim of making destructuring objects as easy as (and more structurally similar to) constructing them.

#language design #java 16 #java #development #article

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Java Feature Spotlight: Pattern Matching
Tyrique  Littel

Tyrique Littel

1600135200

How to Install OpenJDK 11 on CentOS 8

What is OpenJDK?

OpenJDk or Open Java Development Kit is a free, open-source framework of the Java Platform, Standard Edition (or Java SE). It contains the virtual machine, the Java Class Library, and the Java compiler. The difference between the Oracle OpenJDK and Oracle JDK is that OpenJDK is a source code reference point for the open-source model. Simultaneously, the Oracle JDK is a continuation or advanced model of the OpenJDK, which is not open source and requires a license to use.

In this article, we will be installing OpenJDK on Centos 8.

#tutorials #alternatives #centos #centos 8 #configuration #dnf #frameworks #java #java development kit #java ee #java environment variables #java framework #java jdk #java jre #java platform #java sdk #java se #jdk #jre #open java development kit #open source #openjdk #openjdk 11 #openjdk 8 #openjdk runtime environment

Samanta  Moore

Samanta Moore

1620458875

Going Beyond Java 8: Local Variable Type Inference (var) - DZone Java

According to some surveys, such as JetBrains’s great survey, Java 8 is currently the most used version of Java, despite being a 2014 release.

What you are reading is one in a series of articles titled ‘Going beyond Java 8,’ inspired by the contents of my book, Java for Aliens. These articles will guide you step-by-step through the most important features introduced to the language, starting from version 9. The aim is to make you aware of how important it is to move forward from Java 8, explaining the enormous advantages that the latest versions of the language offer.

In this article, we will talk about the most important new feature introduced with Java 10. Officially called local variable type inference, this feature is better known as the **introduction of the word **var. Despite the complicated name, it is actually quite a simple feature to use. However, some observations need to be made before we can see the impact that the introduction of the word var has on other pre-existing characteristics.

#java #java 11 #java 10 #java 12 #var #java 14 #java 13 #java 15 #verbosity

Samanta  Moore

Samanta Moore

1623835440

Builder Design Pattern

What is Builder Design Pattern ? Why we should care about it ?

Starting from **Creational Design Pattern, **so wikipedia says “creational design pattern are design pattern that deals with object creation mechanism, trying to create objects in manner that is suitable to the situation”.

The basic form of object creations could result in design problems and result in complex design problems, so to overcome this problem Creational Design Pattern somehow allows you to create the object.

Builder is one of the** Creational Design Pattern**.

When to consider the Builder Design Pattern ?

Builder is useful when you need to do lot of things to build an Object. Let’s imagine DOM (Document Object Model), so if we need to create the DOM, We could have to do lot of things, appending plenty of nodes and attaching attributes to them. We could also imagine about the huge XML Object creation where we will have to do lot of work to create the Object. A Factory is used basically when we could create the entire object in one shot.

As **Joshua Bloch (**He led the Design of the many library Java Collections Framework and many more) – “Builder Pattern is good choice when designing the class whose constructor or static factories would have more than handful of parameters

#java #builder #builder pattern #creational design pattern #design pattern #factory pattern #java design pattern

Aileen  Jacobs

Aileen Jacobs

1596720944

Proxy Design Pattern in JAVA

In this blog, we will discuss Proxy Design Pattern, its example, and how it is different from the other design patterns. But, it’s important to have an understanding of the design patterns first. You can refer here.

What is a Proxy

A Proxy is something that has the authority to do some activity on behalf of the original object. For example, when you are busy for the day and you have to pay electricity bill. So, your approach would be like you will ask someone else to pay on behalf of you.

Proxy Pattern

In the proxy patterns, a class represents the functionality of another class. These type of design patterns comes under structural patterns. Here, we create an object having original object to interface its functionality to outer world.

Why we need Proxy Pattern

This proxy is helpful when we don’t want to manipulate our main object. It avoids the duplication of objects so less memory is used which turns out to increases the performance of the application. And one of the advantages of Proxy pattern is good security.

Example for Proxy Pattern

Let’s see how to write a program using the Proxy Pattern.

So we start by creating a simple interface.

public interface College  {

    public void attendance(String student) ;

}

#functional programming #java #tech blogs #design pattern #functional java #java #proxy design pattern

Samanta  Moore

Samanta Moore

1620462686

Spring Boot and Java 16 Records

In this article, we will discuss Java 16’s newest feature, Records. Then we will apply this knowledge and use it in conjunction with a Spring Boot application.

On March 16th, 2021, Java 16 was GA. With this new release, tons of new exciting features have been added. Check out the release notes to know more about these changes in detail. This article’s focus will be on Java Records, which got delivered with JEP 395. Records were first introduced in JDK 14 as a preview feature proposed by JEP 359, and with JDK 15, they remained in preview with JEP 384. However, with JDK 16, Records are no longer in preview.

I have picked Records because they are definitely the most favored feature added in Java 16, according to this Twitter poll by Java Champion Mala Gupta.

I also conducted a similar survey, but it was focused on features from Java 8 onwards. The results were not unexpected, as Java 8 is still widely used. Very unfortunate, though, as tons of new features and improvements are added to newer Java versions. But in terms of features, Java 8 was definitely a game-changer from a developer perspective.

So let’s discuss what the fuss is about Java Records.

#java #springboot #java programming #records #java tutorials #java programmer #java records #java 16