#Java jdk

[yoshifawful64]

incidentally does anyone have experience troubleshooting java installation on mac

[elgarnaouicom]

A Comprehensive Guide to Java 17 New Features

Java 17, the latest long-term support (LTS) release, has arrived with a plethora of exciting new features and enhancements. In this blog post, we’ll take an in-depth look at all the noteworthy additions to the Java ecosystem in this groundbreaking release. 1. Sealed Classes Sealed classes provide a new way to restrict the inheritance hierarchy, allowing developers to define a limited set of…

[224vinod]

serialVer - serialVersionUID In Java

Introduction When it comes to working with Java serialization, one of the lesser-known but incredibly important aspects is the serialVersionUID, often referred to as “serialVer.” This seemingly simple numeric value plays a crucial role in maintaining data compatibility between different versions of a Java class. In this blog post, we’ll dive deep into the world of serialVer, exploring its…

[otakubinary]

JAVA 11 LTS -> JAVA 17 LTS Llevaba tiempo sin actualizar el JDK OwO T_T Por eso me fallaba al usar las record class

It has been a while since I updated the JDK That's why code don't compile when i tried to using the record classes

JDKをアップデートしてからしばらく経ちました。 jdk 11 LTS -> jdk 17 LTS だから、レコード・クラスを使おうとすると、コードがコンパイルされないんだ。

[seo1tctct]

Appium setup made easy — Step by step process for Installing/ Configuring Appium & Appium Doctor on macOS for Android platform

[edisilva64-blog-blog]

Guia completo de instalação e configuração do Spring: Spring Core, MVC, Security e mais

O Spring é um framework de desenvolvimento de aplicativos Java que oferece um conjunto abrangente de recursos e ferramentas para criar aplicativos empresariais escaláveis e robustos. Ele foi desenvolvido com o objetivo de simplificar o desenvolvimento de aplicativos Java e promover uma arquitetura limpa e modular. O Spring foi lançado pela primeira vez em 2003 e desde então se tornou um dos…

[dreaminginthedeepsouth]

Women pulling Lever on a Drilling Machine, 1978 Lee, Howl & Company Ltd., Tipton, Staffordshire, England photograph by Nick Hedges image credit: Nick Hedges Photography

* * * *

Tim Boudreau 

About the whole DOGE-will-rewrite Social Security's COBOL code in some new language thing, since this is a subject I have a whole lot of expertise in, a few anecdotes and thoughts.

Some time in the early 2000s I was doing some work with the real-time Java team at Sun, and there was a huge defense contractor with a peculiar query: Could we document how much memory an instance of every object type in the JDK uses? And could we guarantee that that number would never change, and definitely never grow, in any future Java version?

I remember discussing this with a few colleagues in a pub after work, and talking it through, and we all arrived at the conclusion that the only appropriate answer to this question as "Hell no." and that it was actually kind of idiotic.

Say you've written the code, in Java 5 or whatever, that launches nuclear missiles. You've tested it thoroughly, it's been reviewed six ways to Sunday because you do that with code like this (or you really, really, really should). It launches missiles and it works.

A new version of Java comes out. Do you upgrade? No, of course you don't upgrade. It works. Upgrading buys you nothing but risk. Why on earth would you? Because you could blow up the world 10 milliseconds sooner after someone pushes the button?

It launches fucking missiles. Of COURSE you don't do that.

There is zero reason to ever do that, and to anyone managing such a project who's a grownup, that's obvious. You don't fuck with things that work just to be one of the cool kids. Especially not when the thing that works is life-or-death (well, in this case, just death).

Another case: In the mid 2000s I trained some developers at Boeing. They had all this Fortran materials analysis code from the 70s - really fussy stuff, so you could do calculations like, if you have a sheet of composite material that is 2mm of this grade of aluminum bonded to that variety of fiberglass with this type of resin, and you drill a 1/2" hole in it, what is the effect on the strength of that airplane wing part when this amount of torque is applied at this angle. Really fussy, hard-to-do but when-it's-right-it's-right-forever stuff.

They were taking a very sane, smart approach to it: Leave the Fortran code as-is - it works, don't fuck with it - just build a nice, friendly graphical UI in Java on top of it that *calls* the code as-is.

We are used to broken software. The public has been trained to expect low quality as a fact of life - and the industry is rife with "agile" methodologies *designed* to churn out crappy software, because crappy guarantees a permanent ongoing revenue stream. It's an article of faith that everything is buggy (and if it isn't, we've got a process or two to sell you that will make it that way).

It's ironic. Every other form of engineering involves moving parts and things that wear and decay and break. Software has no moving parts. Done well, it should need *vastly* less maintenance than your car or the bridges it drives on. Software can actually be *finished* - it is heresy to say it, but given a well-defined problem, it is possible to actually *solve* it and move on, and not need to babysit or revisit it. In fact, most of our modern technological world is possible because of such solved problems. But we're trained to ignore that.

Yeah, COBOL is really long-in-the-tooth, and few people on earth want to code in it. But they have a working system with decades invested in addressing bugs and corner-cases.

Rewriting stuff - especially things that are life-and-death - in a fit of pique, or because of an emotional reaction to the technology used, or because you want to use the toys all the cool kids use - is idiotic. It's immaturity on display to the world.

Doing it with AI that's going to read COBOL code and churn something out in another language - so now you have code no human has read, written and understands - is simply insane. And the best software translators plus AI out there, is going to get things wrong - grievously wrong. And the odds of anyone figuring out what or where before it leads to disaster are low, never mind tracing that back to the original code and figuring out what that was supposed to do.

They probably should find their way off COBOL simply because people who know it and want to endure using it are hard to find and expensive. But you do that gradually, walling off parts of the system that work already and calling them from your language-du-jour, not building any new parts of the system in COBOL, and when you do need to make a change in one of those walled off sections, you migrate just that part.

We're basically talking about something like replacing the engine of a plane while it's flying. Now, do you do that a part-at-a-time with the ability to put back any piece where the new version fails? Or does it sound like a fine idea to vaporize the existing engine and beam in an object which a next-word-prediction software *says* is a contraption that does all the things the old engine did, and hope you don't crash?

The people involved in this have ZERO technical judgement.

[erik-even-wordier]

About the whole DOGE-will-rewrite Social Security's COBOL code

Posted to Facebook by Tim Boudreau on March 30, 2025.

About the whole DOGE-will-rewrite Social Security's COBOL code in some new language thing, since this is a subject I have a whole lot of expertise in, a few anecdotes and thoughts.

Some time in the early 2000s I was doing some work with the real-time Java team at Sun, and there was a huge defense contractor with a peculiar query: Could we document how much memory an instance of every object type in the JDK uses? And could we guarantee that that number would never change, and definitely never grow, in any future Java version?

I remember discussing this with a few colleagues in a pub after work, and talking it through, and we all arrived at the conclusion that the only appropriate answer to this question as "Hell no." and that it was actually kind of idiotic.

Say you've written the code, in Java 5 or whatever, that launches nuclear missiles. You've tested it thoroughly, it's been reviewed six ways to Sunday because you do that with code like this (or you really, really, really should). It launches missiles and it works.

A new version of Java comes out. Do you upgrade? No, of course you don't upgrade. It works. Upgrading buys you nothing but risk. Why on earth would you? Because you could blow up the world 10 milliseconds sooner after someone pushes the button?

It launches fucking missiles. Of COURSE you don't do that.

There is zero reason to ever do that, and to anyone managing such a project who's a grownup, that's obvious. You don't fuck with things that work just to be one of the cool kids. Especially not when the thing that works is life-or-death (well, in this case, just death).

Another case: In the mid 2000s I trained some developers at Boeing. They had all this Fortran materials analysis code from the 70s - really fussy stuff, so you could do calculations like, if you have a sheet of composite material that is 2mm of this grade of aluminum bonded to that variety of fiberglass with this type of resin, and you drill a 1/2" hole in it, what is the effect on the strength of that airplane wing part when this amount of torque is applied at this angle. Really fussy, hard-to-do but when-it's-right-it's-right-forever stuff.

They were taking a very sane, smart approach to it: Leave the Fortran code as-is - it works, don't fuck with it - just build a nice, friendly graphical UI in Java on top of it that *calls* the code as-is.

We are used to broken software. The public has been trained to expect low quality as a fact of life - and the industry is rife with "agile" methodologies *designed* to churn out crappy software, because crappy guarantees a permanent ongoing revenue stream. It's an article of faith that everything is buggy (and if it isn't, we've got a process or two to sell you that will make it that way).

It's ironic. Every other form of engineering involves moving parts and things that wear and decay and break. Software has no moving parts. Done well, it should need *vastly* less maintenance than your car or the bridges it drives on. Software can actually be *finished* - it is heresy to say it, but given a well-defined problem, it is possible to actually *solve* it and move on, and not need to babysit or revisit it. In fact, most of our modern technological world is possible because of such solved problems. But we're trained to ignore that.

Yeah, COBOL is really long-in-the-tooth, and few people on earth want to code in it. But they have a working system with decades invested in addressing bugs and corner-cases.

Rewriting stuff - especially things that are life-and-death - in a fit of pique, or because of an emotional reaction to the technology used, or because you want to use the toys all the cool kids use - is idiotic. It's immaturity on display to the world.

Doing it with AI that's going to read COBOL code and churn something out in another language - so now you have code no human has read, written and understands - is simply insane. And the best software translators plus AI out there, is going to get things wrong - grievously wrong. And the odds of anyone figuring out what or where before it leads to disaster are low, never mind tracing that back to the original code and figuring out what that was supposed to do.

They probably should find their way off COBOL simply because people who know it and want to endure using it are hard to find and expensive. But you do that gradually, walling off parts of the system that work already and calling them from your language-du-jour, not building any new parts of the system in COBOL, and when you do need to make a change in one of those walled off sections, you migrate just that part.

We're basically talking about something like replacing the engine of a plane while it's flying. Now, do you do that a part-at-a-time with the ability to put back any piece where the new version fails? Or does it sound like a fine idea to vaporize the existing engine and beam in an object which a next-word-prediction software *says* is a contraption that does all the things the old engine did, and hope you don't crash?

The people involved in this have ZERO technical judgement.

[forever-stuck-on-java-8]

We used Hadoop at school today. We had 4 hours. We spent 2 of those installing, you guessed it, Java™ 8. Some poor soul did everything with the JRE instead of the JDK and had to start over. I have so much respect for people who deal with java in their actual job, i can't stand the damn thing.

thanks, that means a lot.

🙏

[nectoy7]

My First Java Program: A Journey into Coding

Starting with Java programming can be an exciting journey, filled with discovery, challenges, and a sense of accomplishment. My experience of writing my first Java program was a significant milestone that opened up a world of possibilities in software development. In this blog, I’ll share my journey through writing my first Java program, along with the concepts I learned and the obstacles I overcame.

The Excitement of Starting

When I first decided to learn Java, I was motivated by its versatility and widespread use in developing applications, from mobile apps to enterprise software. I had heard about the power of Java and how it is a foundational language for many developers. After setting up my Java development environment, which included installing the Java Development Kit (JDK) and choosing an Integrated Development Environment (IDE) like Eclipse, I was ready to dive in.

The anticipation of writing my first program filled me with excitement. I had heard many experienced programmers talk about how exhilarating it felt to see their code come to life, and I was eager to experience that feeling myself.

Setting Up the Development Environment

Before I could write my first program, I needed to ensure my development environment was properly configured. Here’s a brief overview of how I set it up:

1. Installing the JDK: I downloaded the latest version of the Java Development Kit from the Oracle website. This included everything I needed to compile and run Java applications.

2. Choosing an IDE: I chose Eclipse as my IDE because of its robust features and user-friendly interface. After downloading and installing it, I was ready to start coding.

3. Verifying the Installation: I opened the command prompt (or terminal) and typed java -version to confirm that Java was installed correctly. Seeing the version number displayed confirmed that I was on the right track.

Writing My First Java Program

With my development environment set up, I was finally ready to write my first Java program. Following the traditional approach, I decided to create a simple “Hello, World!” program. This classic exercise is often the first step for beginners learning any programming language.

Step 1: Creating a New Java Project

In Eclipse, I created a new Java project:

1. File > New > Java Project.

2. I named the project “HelloWorld” and clicked Finish.

Step 2: Creating a New Java Class

Next, I created a new Java class within the project:

1. Right-click on the src folder in the HelloWorld project.

2. Selected New > Class.

3. I named the class HelloWorld and checked the box to include the public static void main(String[] args) method. This method is the entry point of any Java application.

Step 3: Writing the Code

With the class created, I wrote the code that would print “Hello, World!” to the console:

public class HelloWorld {     public static void main(String[] args) {         System.out.println(“Hello, World!”);     } }

Code Explanation

public class HelloWorld: This line defines a public class named HelloWorld. In Java, every application must have at least one class.

public static void main(String[] args): This line declares the main method, which is the starting point of any Java program. The JVM (Java Virtual Machine) looks for this method when executing the program.

System.out.println(“Hello, World!”);: This line prints the string “Hello, World!” to the console. The System.out object is used to output data to the console, and println is a method that prints the text followed by a newline.

Step 4: Running the Program

After writing the code, it was time to run my program and see the result:

1. I right-clicked on the HelloWorld.java file in the Project Explorer.

2. Selected Run As > Java Application.

To my delight, the console displayed the message “Hello, World!” It was a simple program, but seeing the output felt like a monumental achievement. I had successfully written and executed my first Java program!

Learning from the Experience

The process of writing my first Java program taught me several important lessons:

Understanding Java Syntax

Java has a specific syntax that must be followed. This includes rules about naming conventions, the use of semicolons to end statements, and the structure of classes and methods. Understanding these rules is essential for writing valid Java code.

The Importance of the Main Method

The main method is crucial in Java applications. It serves as the entry point, and every program must have it to be executed. Learning this concept helped me appreciate how Java applications are structured.

The Power of Output Statements

Using System.out.println() was my first experience with output statements. It highlighted the importance of feedback in programming. Being able to print messages to the console is invaluable for debugging and understanding program flow.

Overcoming Challenges

While writing my first Java program was largely straightforward, I faced some challenges along the way:

Syntax Errors

Initially, I encountered syntax errors due to missing semicolons or misnamed classes. Each error message provided insight into what I needed to correct. This experience emphasized the importance of careful coding and attention to detail.

Understanding the IDE

Familiarizing myself with Eclipse took some time. I had to learn how to navigate the interface, manage projects, and use features like code suggestions and debugging tools. As I continued coding, I became more comfortable with the IDE.

Next Steps in My Java Journey

Completing my first Java program was just the beginning. With a foundational understanding of Java syntax and structure, I was excited to explore more advanced concepts. Here are the next steps I took in my learning journey:

Exploring Java Basics

I delved deeper into Java basics, including:

Data Types: Understanding primitive and reference data types.

Variables: Learning how to declare and use variables effectively.

Operators: Exploring arithmetic, relational, and logical operators.

Control Flow Statements: Mastering if-else, switch, and loop constructs.

Learning Object-Oriented Programming (OOP)

Java is an object-oriented programming language, and I knew I had to understand OOP principles. I focused on concepts such as:

Classes and Objects: Learning how to create and manipulate objects.

Inheritance: Understanding how classes can inherit properties from other classes.

Encapsulation: Learning how to hide data within classes.

Polymorphism: Exploring method overloading and overriding.

Building Projects

I started working on small projects to apply my knowledge. Simple applications, like a calculator or a text-based game, helped solidify my understanding of Java concepts.

Conclusion

Writing my first Java program was a thrilling experience that marked the beginning of my journey as a programmer. The excitement of seeing my code come to life, coupled with the knowledge I gained, fueled my desire to continue learning and growing in the field of software development.

Java has proven to be a powerful language with endless possibilities, and I am eager to explore its depths further. With each program I write, I feel more confident in my coding abilities and more inspired to tackle new challenges.

If you’re starting your Java journey, embrace the process, celebrate your successes, and don’t shy away from challenges. Each step you take brings you closer to becoming a proficient Java developer.

Happy coding!

[elgarnaouicom]

Exploring the Exciting Java 21 New Features

Introduction: Java 21 has landed, bringing along a treasure trove of new features and enhancements designed to streamline development workflows and empower Java programmers worldwide. In this comprehensive blog post, we’ll explore each of the exciting new features introduced in Java 21, accompanied by code examples to illustrate their practical applications. Let’s embark on a journey through the…

[224vinod]

Pack200 - Java Tool

Introduction: In the ever-evolving world of Java development, optimizing application performance is a constant challenge. One technique that can significantly enhance your Java application’s performance is Pack200. In this blog post, we’ll dive deep into Pack200, exploring its features, usages, and providing code samples to help you harness its power effectively. What is Pack200? Pack200 is a…

[mumblingstudent]

Как создать и запустить у себя Java апплет в 2024 году?

Апплеты - устаревшая технология, которая позволяла запускать java-программы в браузере пользователя.

В JDK 9 они были объявлены устаревшими, а в JDK 11 их уже не было. Поэтому в первую очередь на компьютере нам понадобится JDK 8

В папке создаём java-ф��йл и html-файл

Java-код для простого апплета, состоящего из надписи и кнопки

HTML-код

Открываем командную строку (это можно сделать прямо из папки, кликнув на путь к ней в проводнике и введя "cmd", enter), компилируем MyApplet.java, после чего запускаем апплет командой "appletviewer Applet.html"

Готово

[roseliejack123]

Mastering Java: Your Comprehensive Guide to Programming Excellence

Embarking on the journey of mastering Java is akin to entering a realm of endless possibilities. Java, a versatile and widely-utilized programming language, offers a broad spectrum of applications, from crafting web and mobile applications to powering robust enterprise systems. Whether you are a novice in the realm of coding or a seasoned programmer looking to broaden your skill set, the path to proficiency in Java is an exciting one.

In this comprehensive guide, we will be your guiding light through the intricacies of Java, starting from the foundational basics and progressing to the more advanced aspects of the language. Our objective is to equip you with the knowledge and skills that form a robust and unshakable foundation for your journey into the vibrant world of Java. Fasten your seatbelt as we embark on this exhilarating exploration, charting a course that will empower you to thrive in the ever-evolving landscape of software development.

Here's a 8-step guide to effectively learn Java

Step 1: Setting Up Your Development Environment

Your journey to becoming a proficient Java developer commences with setting up your development environment. The essential components are the Java Development Kit (JDK) and an Integrated Development Environment (IDE) like Eclipse or IntelliJ IDEA. These tools aren't just convenient; they're the gears that will drive your Java programming endeavors. They streamline the coding process, provide useful features, and offer an organized workspace, making your coding experience efficient and enjoyable.

Step 2: The Foundation - Learning the Basics

With your development environment ready, it's time to delve into the fundamental building blocks of Java. Begin by acquainting yourself with data types, variables, operators, and control structures. These are the nuts and bolts of the language, and a solid grasp of these concepts is essential. You'll find an abundance of online tutorials and beginner-friendly Java books to assist you at this stage.

Step 3: Navigating the World of Object-Oriented Programming (OOP)

The object-oriented programming (OOP) approach is well known in Java. To harness the true power of Java, immerse yourself in the world of OOP. Understand the concepts of classes, objects, inheritance, encapsulation, and polymorphism. This knowledge forms the bedrock of Java programming and enables you to design efficient, organized, and scalable code.

Step 4: Mastering Data Structures and Algorithms

Data structures (such as arrays, lists, and sets) and algorithms are the secret sauce behind solving real-world problems efficiently. As you progress, dive into the world of data structures and algorithms. These are the tools that will empower you to handle complex tasks and optimize your code. They're your go-to assets for creating efficient and responsive applications.

Step 5: The Art of Exception Handling

Java boasts a robust exception-handling mechanism. Understanding how to handle exceptions properly is not just an add-on skill; it's a vital aspect of writing reliable code. Exception handling ensures that your code gracefully manages unexpected situations, preventing crashes and delivering a seamless user experience.

Step 6: Exploring Input and Output Operations

In this step, you'll explore the realm of input and output (I/O) operations. Mastering I/O is crucial for reading and writing files, as well as interacting with users. You'll gain the ability to build applications that can efficiently process data and communicate effectively with users.

Step 7: Conquering Multi tasking

Java's support for multi tasking is a significant advantage. Understanding how to manage threads and synchronize their actions is vital for creating concurrent applications. Multithreading is the key to developing software that can handle multiple tasks simultaneously, making your applications responsive and scalable.

Step 8: Building Projects and Real-World Practice

Theory is only as valuable as its practical application. The final step involves applying what you've learned by building small projects. These projects serve as a proving ground for your skills and provide valuable additions to your portfolio. Whether it's a simple application or a more complex project, the act of building is where the real learning takes place.

As you step into this vibrant realm of Java, remember that continuous learning is the key to staying relevant and effective in the ever-evolving field of software development. Be open to exploring diverse applications, from web development to mobile apps and enterprise solutions, and never underestimate the power of hands-on practice. Building projects, no matter how small, will solidify your knowledge and boost your confidence.

In your quest to master Java, ACTE Technologies stands as a valuable ally. Their expert guidance and comprehensive training programs will sharpen your skills, boost your confidence, and pave the way for a rewarding career in software development. Whether you're embarking on your Java journey or looking to take your skills to the next level, ACTE Technologies offers the resources and support you need to thrive in the world of Java programming.

So, with Java as your trusty companion, and ACTE Technologies as your guide, the possibilities are boundless. Your journey is just beginning, and the world of software development awaits your innovation and expertise. Best of luck on your path to mastering Java!