First of all, I wish you all a Happy New Year.Have a good time during the holidays?

Last year, the stacker gave you an inventory of "Several Events in the Java Development Industry in 2020", 2022 has come, and we must also summarize 2021.What are the things worth paying attention to in the "Java Technology Stacking" in 2021 Woolen cloth?

This article must be read, because these technical events may affect your future employment and the company's decision-making on technology selection.Spend a little more time and master a little more technology, and you will be able to walk ahead of others,

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2021 big summary

1.Programming Language Ranking

The latest TIOBE programming language rankings are as follows:

Python finally beats C to become the new king in October 2021,

This is also the first new king language after C and Java in the past 20 years.The era of Java and C dominating the list for a long time has come to an end.Java has dropped one place from last year, and now it has become The third child,,,

Although Java seems to be going downhill, don't be discouraged.This is just a list.It does not mean that the Java ecosystem is going downhill, nor does it mean that Java is not worth learning.It can only be said that Java has become stable.Because of this stability, the number of times Java is searched, downloaded, and learned on the Internet has not grown so explosively, so it will create an illusion that Java is going downhill,

So, we should learn and go to work.Don't be affected by the rankings.Java is still one of the most popular languages.Now there are countless Java jobs, a fiery open source community, a strong and rich ecosystem, and one family after another.An online training organization is out of the ground, which says it all, Java is still old and strong, and the market is the best witness,

2, JDK 17 release

Since the JDK has changed the version rules, this version cannot be stopped.By the end of 2021, Oracle has released two versions:

• JDK 16 (2021/03/16)
• JDK 17 (2021/09/14)

JDK 16 is not a long-term support release, only supported for 6 months through September 2021,

JDK 17 is the second long-term support release after JDK 11 in 2018, and can be supported until September 2029.The next long-term support release is JDK 21, which will be released in 2023,

Check out the latest Oracle Java Support Roadmap:

In 2022, JDK 18 and 19 will be released one after another.Can you keep up?

However, JDK 18, 19 are not long-term support versions, there is no need to chase, you can ignore!

3, JDK is officially free

Oracle announces that JDK 17 is officially free, including commercial use:

Oracle changes JDK charging terms in 2021:

The JDKs released after JDK 17 are all free, but the previous version should still be charged,

It should be noted that JDK 17 is not free for long-term commercial use.At present, it is only supported until September 2024.After that, it may be charged or continue to be free.This uncertainty is a bit unacceptable,

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4.Java coroutine is coming

We all know that Java's current smallest system scheduling unit only supports threads, and officially does not support coroutines, but in the near future, Java will start to support coroutines:

On the official website of openjdk, a new feature was created on 2021/11/15: JEP draft: Virtual Threads (Preview)

This is still a draft, preview features, many details are not very sure, is it called coroutine? Or fibers? Or virtual threads? There is no official Chinese information now, it doesn't matter what it is called, we all know that the "coroutine" in Java is coming!

Because the cost of using threads is very high, there is a virtual thread, which is a user-mode thread, and the cost is quite low, which fully improves the hardware utilization, and also increases the amount of high concurrency.stage, enabling high throughput,

For a more detailed explanation, please click the link to review:

Understand and pay attention to the latest Java technology trends, please pay attention to the Java technology stack of the official account, the official account will push it as soon as possible,

5, Log4j2 Nuclear Bomb Vulnerability

The recent nuclear bomb-level vulnerability in Apache Log4j2 must be known to everyone, and it has caused a lot of sensation.The circle of friends and technology circles are all fried, and all kinds of emergency are launched.

After the Log4j2 nuclear bomb-level vulnerability ended, various vulnerabilities were found, and the latest version has been released from v2.15.0 to v2.17.1:

JDK version	Log4j2 latest security version
Java 8+	v2.17.1
Java 7	v2.12.4
Java 6	v2.3.2

There are 5 known vulnerabilities fixed:

• CVE-2021-44832 (Remote Code Execution Vulnerability)
• CVE-2021-45105 (Denial of Service Vulnerability)
• CVE-2021-45046 (Remote Code Execution Vulnerability)
• CVE-2021-44228 (Remote Code Execution Vulnerability)
• Information disclosure vulnerability (discovered by security firm Praetorian)

It's numb, it's numb, I've been tossing it for more than half a month, and now I can't see the sign of the end, it's really crazy,

Another thing to note is that Logback has also exploded recently:

Log4j 1.x has long stopped maintenance, and there are also unrepaired vulnerabilities, so it is not recommended to use it:

The stack leader of the vulnerability is still paying attention.The stack leader will notify you when there is the first progress.Follow the official account Java technology stack, and the official account will push it as soon as possible.

6, Spring family

As a Java developer, I have to pay attention to the development of Spring,

version 6.1 update

Let's take a look at the latest editions of several key projects for 2021:

Projects	version number
Spring Framework	5.3.14
Spring Boot	2.6.2
Spring Cloud	2021.0.0
Spring Security	5.6.1
Spring Data	2021.1.0

Spring Boot is the core of the entire Spring family and complements each other.We also develop based on Spring Boot.The latest version of Spring Boot must be understood and planned in advance:

Spring Boot has been released to 2.6.x, and 2.5.x is also the last security version.Which version are you using, the technology is updated too fast, and many companies may not be able to keep up.

Spring Boot 2.7.x will meet with you in less than half a year, when the stack is long, I will give you a detailed explanation.You can continue to pay attention to the official account Java technology stack, the official account No.1 One time push,

The basics of Spring Boot will not be introduced, but this practical tutorial is recommended:

6.2, kill JVM

Spring launched the Spring Native Beta version in March of this year, no JVM environment required, which provides another way to run and deploy Spring applications.The application is compiled into a native image,

The other two advantages of Spring Native are fast startup and low memory usage.

Typically, it takes about 15 seconds to run a JVM-based application, and under 100 milliseconds to run a Spring Native native application:

As shown in the figure, the stack was tested for a long time, and it started in 82 milliseconds.The startup was really fast,

More Spring Native introduction and actual combat can click on the link to review:

In addition, although Spring Native has killed the JVM, it does not mean that Spring has killed the JVM.Other Spring projects that depend on the JVM are still running normally.The JVM system will not die at present, and the two do not conflict.

6.3 Kill Spring Security OAuth

The Spring Security OAuth project has been deprecated:

The Spring Security OAuth project has been taken over by the Spring Security project, and neither is Spring SecurityIncluding support for Authorization Server,

Later, Spring continued to provide support for Authorization Server under the voice of the masses, and launched the Spring Authorization Server project, which will be officially converted in 2021,

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For a more detailed explanation, please click the link to review:

7, Kafka deprecates Java 8

Kafka 3.0.0 is released:

The first is to announce the deprecation of support for Java 8 and Scala 2.12! ! !

But 3.0.0 can still be used.This announcement is just to give users a time to adjust.When Kafka 4.0 comes, Java 8 and Scala 2.12 will officially cancel support.

Actually, some other middleware have already stopped supporting Java 8, and choose Java 11 as the minimum supported version.Although Java 8 is a bit old, it is still the most used version on the market, although some middleware Java 8 is no longer supported, but actual development jobs are not affected,

For a more detailed explanation, please click the link to review:

I also wrote a bunch of Java 8+ series of tutorials, pay attention to the official account Java technology stack and read it in the menu bar,

8, CentOS 8 officially terminated

CentOS Linux 8 was discontinued on December 31, 2021:

The termination of CentOS 8 means that CentOS Stream will be in the world from now on,

RHEL (Red Hat Enterprise Linux) is this forcing everyone to use the paid version? The mystery of this is only clear to itself!

So it is not recommended to use CentOS Stream in the production environment.Those who have already used CentOS 8 are also recommended to return to CentOS 7.After all, CentOS 7 is still mainstream, stable, reliable, and supported until June 30, 2024.day, no impact in the short term,

Will you use CentOS Stream after 2024? Or will you choose the paid version? I will still choose other Linux distributions, the stack leader will continue to pay attention, pay attention to the official account Java technology stack, the official account will push it as soon as possible,

For a more detailed explanation, please click the link to review:

9.LayUI official website offline

The official layui website will be offline on October 13, 2021:

It should be noted that LayUI is only offline from the official website, but it does not mean the end, it does not mean that LayUI stops maintenance, subsequent new versions are released, and routine maintenance operations have been migrated to the Github/gitee code hosting platform

In addition, LayUIAdmin and LayIM will also be migrated to the new official website, and only a download channel is reserved for old users.Both will no longer be open to new users.

In the past few years, like the back-end framework, the front-end framework has also changed wave after wave.Now Vue.js, React, and AngularJS are leading the development trend of the front-end framework.The old LayUI does not have an advantage., pay attention to the public account Java technology stack, reply: vue, you can get the latest Vue 3.0 HD PDF tutorial,

More can click on the link to read the previous review:

10.New Generation Migrant Workers

Remember this wave of crazy reposts in the circle of friends?

The self-deprecating self-deprecation of this new generation of IT workers is also hilarious, and the circle of friends has been occupied again,

Actually, it's a bit too much to say that we include IT personnel in "New Generation Migrant Workers",

After stacking, let's clarify the definition of New generation of migrant workers:

• Post-80s
• Age 16 and older
• Rural Hukou
• Working offsite
• Working in non-agricultural industries

Meet the above 5 points at the same time, you are "New Generation Migrant Workers"! ! !

So, "New Generation Migrant Workers" does not mean IT migrant workers, but represents the whole industry.That announcement only amplifies IT migrant workers, and the official just wants to emphasize It is said that the IT migrant workers have greatly improved.The relationship between the two is not==, but the relationship of contains:

For a detailed interpretation, you can click the link to read the previous review:

2022 is coming!

Okay, 2021 summarizes some major events of Java technology stacking for you, I hope it will be helpful to you,

In 2022, the stack leader will continue to set sail and output more technical dry goods and information to everyone, Follow the public account Java technology stack, don't get lost,

Finally, I wish you all a Happy New Year 2022, a prosperous Year of the Tiger, and a prosperous and prosperous Tiger! !

No need for appreciation, if you have knowledge, just forward a wave, thank you for your support~

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