Java for All! I read everyone's Java #minjava

I read everyone's Java!

I received a copy from a person who wants to become (detailed) in the author's JVM (@jyukutyo). Thank you! It was a book I just wanted to read, so I was very happy.

What kind of book?

This is a book about Java now. Even those who have followed the technological trends of Java, such as generics introduced in Java 5 and lambda introduced in Java 8, may not be able to keep up with the speed of change after Java 9. Since the release of Java 9, we have decided to raise the major version once every six months in March and September. Along with this, Java has begun to evolve normally again, dispelling the legacy that comes from the delay in evolution. If you're new to Java in the olden days, this book will help you discover amazing Java evolution and potential.

How long can you read it?

Celebrities familiar with each field describe their areas of expertise. I'm slow to read books, but if I concentrate, it's enough volume to read in 2 hours per chapter. There are 6 chapters, so if you are quick to read, you can read it in a day.

After reading each chapter, the technology you care about is structured so that you can follow it deeply. It is difficult to collect these contents online. It was compactly organized, and I was able to acquire knowledge very efficiently.

What kind of person do you recommend?

I think it can be recommended for the following people.

--For those who want to know the latest Java trends --Those who are wondering which JDK distribution to choose --Those who are interested in serverless and microservices --Those who are interested in new technology

On the other hand, please note that it is not for those who are going to study Java from now on.

Impressions of each chapter

Chapter 1 Evolving Java! Introducing Java changes from Java 9 to 14

Introducing changes in language specifications and standard libraries from Java 9 to 14. My favorite technological changes are:

--Local variable type inference --Private method in interface --Switch type --Shield type --Pattern matching --New HTTP Client

Many other technological changes are introduced. What we look forward to in the future is the lightweight thread being developed by Project Loom.

Even though I have been developing with Java for many years, I am surprised at the speed of change after Java 9. I wrote in "Introduction"

"Java has become something we all make. 』\

It was the beginning chapter that seemed to be exactly.

Chapter 2 Don't hesitate anymore! ?? Thorough explanation of JDK distribution

The announcement of the license change of Oracle JDK / JRE caused confusion such as "Java is paid !?" This turmoil is partly due to the efforts of volunteers, and I think it has been settled for the time being. On the other hand, "Which JDK distribution should I use?" Is one of the concerns of engineers at each site.

This chapter explains from the history of OpenJDK and JDK distributions, and I think that it is the information that is gathered together today in deciding "which JDK distribution to adopt". It was also a chapter on how Oracle has contributed to Java and will continue to contribute in the future.

Engineers in the field who utilize Java should read it once.

Chapter 3 What is Jakarta EE! ?? What's new in Enterprise Java

Chapter 3 is "New Enterprise Java". Rather than introducing new features, it is a chapter where you can learn about the history leading up to Jakarta EE. In the field, systems written in Java EE are still in operation, and it would be good to have the knowledge of this chapter when considering future enhancements. I also remember making a mobile API with JAX-RS a long time ago. Now it's called Jakarta RESTful Web Services. I did not know!

Chapter 4 Microservices in Java! Introducing MicroProfile

A chapter on MicroProfile, a community standard for microservices.

--Community-led --Priority is given to the implementation that works over the specifications --Frequent and regular releases

That is the current policy. I am also interested in future specification development such as Long Running Actions and GraphQL. I think that the knowledge of this chapter will be useful for learning about the Java lightweight framework "Quarkus" that will appear in Chapter 6 after this.

Chapter 5 The hottest right now! ?? Introducing GraalVM

This is a story about GraalVM, which expands the possibilities of next-generation Java at once. I feel some love over all pages w

"GraalVM is a technology that generates native images in Java, isn't it?"

If you are familiar with this, please take a look at this chapter. You'll know the real awesomeness of GraalVM. There may be a future where all languages run on GraalVM and native image Java runs in various environments. It is wonderful!

Chapter 6 Don't let me say you can't use it with Lambda! Serverless [new generation] Java lightweight framework

Introducing the next-generation lightweight Java framework that emerged from the background of microservices and serverless. You can compare and know the features of frameworks such as Micronaut / Quarkus / Helidon that may be active in the next generation.

Regarding the Java framework, I thought it would be one of the strongest eras of Spring Boot, but now there is a strong opponent. it's interesting! Do I like Quarkus? If I have time somewhere, I would like to follow it. On top of that, I felt that this chapter was useful as an introduction.

Summary

This book was very helpful because I myself had stopped knowing about Java 8. Recently, there are many technologies for developing applications, and it is difficult to pursue only one technology in depth. In such a case, it would be very helpful to have a comprehensive information like this one.

Thank you to all the authors.