Core Java APIs and programming techniques
Technologies related to Java APIs (application programming interfaces) and JDK (Java Development Kit) form the cornerstone of modern, enterprise-grade software development. Here we explore all the Java features that make the JVM great through programming tutorials, real-world code samples and expert opinions from Java champions.
Top Stories
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Video
20 Nov 2024
OpenAPI, Swagger and Python
Looking for an easy way to create, test and document your RESTful APIs written in Python? Swagger and OpenAPI make it easy. This tutorial shows you how to do it. Continue Reading
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Tip
19 Nov 2024
Top 10 Jenkins alternatives
Tired of the overhead of hosting your own Jenkins installation and looking for some alternatives? Here are 10 of the best. Continue Reading
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Tip
08 Nov 2024
Webhooks explained simply, with examples
Webhooks make significant use of basic API call mechanisms and set event triggers in a few clicks of a button -- all without the overhead of heavy request-response structures. Continue Reading
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Definition
06 Nov 2024
What is Mojo programming language and what is it used for?
Mojo is a high-performance programming language initially designed to unify and simplify the development of applications across all layers of the AI stack. Continue Reading
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Video
05 Nov 2024
Create a React Hello World program
Discover a new take on the classic React Hello World program. Go beyond the basics and explore state management, event handling and best practices to build progressive web apps. Continue Reading
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Video
01 Nov 2024
Spring Boot CRUD operations
What's your preferred approach to perform Spring CRUD operations? I always choose Spring Data's CrudRepository. Anything else is too much work. Continue Reading
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Video
01 Nov 2024
SQLite tutorial for beginners
SQLite has an incredibly small footprint. That's one of the reasons why it's the most used database engine in the world. If you've never used it before, here's your chance. Continue Reading
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Video
01 Nov 2024
Java, JDBC and Postgres
Postgres has become popular in the Java community for many reasons. The ease of integration with Java apps through JDBC is one of the biggest. Here's how it works. Continue Reading
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Blog Post
01 Nov 2024
Get started with Spring Boot 3 tutorial
Need to learn Spring Boot 3? Want to quickly build a Spring Boot app with RESTful web services? This tutorial will help you create your first Spring Boot application in just minutes. Continue Reading
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Video
31 Oct 2024
Spring Boot Actuator tutorial
What's the easiest way to get insights into how your Spring Boot applications are running? The Spring Boot Actuator is the answer. Continue Reading
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Video
31 Oct 2024
Spring Boot ConfigurationProperties tutorial
Need to convert structured data in a Spring YAML or properties file into lists, maps and inner classes? Just use the @ConfigurationProperties decoration in Spring Boot. Continue Reading
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Tip
21 Oct 2024
When to use Rust vs. Python
This Rust vs. Python faceoff breaks down how the two programming languages stack up against each other in terms of performance, speed, memory management and more. Continue Reading
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Video
11 Oct 2024
Git commit message conventions and best practices
Never underestimate the power of a good git commit message. Need help writing one? Here are the commonly accepted git commit message guidelines and best practices. Continue Reading
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Video
10 Oct 2024
Spring profiles in Spring Boot tutorial
Ever struggle with the constant discrepancies between dev, UAT and production? Spring profiles make such configuration issues a thing of the past. Here's how they work. Continue Reading
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Tip
08 Oct 2024
Rust vs. C++: Differences and use cases explained
C++ was mature before Rust even existed. Does that mean developers should switch from C++ to Rust? Not always. Continue Reading
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Tip
08 Oct 2024
HCL vs. JSON: Configuration language uses, pros and cons
HCL and JSON are similar configuration languages. These languages are meant for specific IaC scenarios, so companies should understand the syntax and editing tools for each. Continue Reading
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Blog Post
07 Oct 2024
Database transaction isolation levels tutorial
Repeatable? Isolated? Serializable? Uncommitted? None? Just how well do you know your database isolation levels, and how do you know if you're using the right one? Here's how you know. Continue Reading
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Tip
04 Oct 2024
How to solve the pinning problem in Java virtual threads
Virtual threads in Java offer many benefits, but they're not a drop-in replacement for traditional threads. Understand and plan around their limitations, most notably pinning. Continue Reading
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Tip
04 Oct 2024
The interface segregation principle: A fun and simple guide
Want a fun way to learn the interface segregation principle of SOLID object-oriented design? Imagine a remote control that tries to do everything but just mucks it all up. Continue Reading
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Tip
03 Oct 2024
Simplifying native interoperability in Java with JEP 454
Finalized in Java 22, JEP 454 helps developers safely and efficiently call native functions and manage memory outside of Java. Here's a rundown of how it works. Continue Reading
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Tip
03 Oct 2024
What's wrong with Java? Nothing, but evaluate alternatives
Java's benefits don't always fit a given task, and a different language might be a better choice. Use these comparisons to choose the best code for your needs. Continue Reading
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Tip
02 Oct 2024
An introduction to TypeSpec, a new API definition language
Standardizing API descriptions and converting API definitions into different formats can be challenging. TypeSpec, a new API definition language, aims to solve that. Continue Reading
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Blog Post
01 Oct 2024
Benefits of Spring Boot's application.yml file with examples
Are you still stuck in the dark ages, configuring your Spring Boot apps with application.properties files? You really should start using an appliation.yml file. Here's just a few of the benefits ... Continue Reading
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Blog Post
30 Sep 2024
Profiles, Spring Boot and application properties files
Spring profiles are a powerful and flexible tool for Java developers to build scalable, enterprise-grade applications, from customizing configurations to altering IoC behavior across environments. Continue Reading
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Tutorial
24 Sep 2024
OpenAI API tutorial: How to use AI prompt chaining
This walkthrough teaches developers how to chain AI prompts and models using the OpenAI API, in this case to identify and present specific data from William Shakespeare plays. Continue Reading
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Video
04 Sep 2024
Model-view-controller design pattern tutorial
How well do you know the MVC design pattern? The basic concept is simple, but the details trip up many developers. This deep dive explores what MVC is and how to best implement it. Continue Reading
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Video
19 Aug 2024
Spring Web MVC crash course
There's still a place in the world for server-side rendering. Learn the Java way to build HTTP responses on the server with this Spring MVC crash course for beginners. Continue Reading
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Video
16 Aug 2024
How to deploy Spring Boot apps in AWS
You don't need a Kubernetes cluster to host your cloud-native Spring Boot microservices. Learn how to quickly deploy your Spring Boot applications in AWS using ECS and Fargate. Continue Reading
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Definition
14 Aug 2024
What is an API (application programming interface)?
An application programming interface (API) is code that enables two software programs to communicate. Continue Reading
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Video
13 Aug 2024
Standalone Spring Boot console apps with CommandLineRunner
Want to create a Spring Boot application that runs at the command line? It's easy. Simply implement the CommandLineRunner interface, and override the required run method. Here's how. Continue Reading
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Video
06 Aug 2024
OpenAPI, Swagger and Spring Boot REST APIs
It's easy to integrate Swagger into your Spring Boot apps with SpringDoc's OpenAPI starter. Code generation, documenting REST APIs and testing endpoints has never been easier. Continue Reading
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Video
29 Jul 2024
Java tic-tac-toe game coding tutorial
What's the best way to learn how to program? Code up some of your favorite childhood games. Here, we'll show you how to code a tic-tac-toe game in Java. Continue Reading
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Tutorial
29 Jul 2024
Natural language programming using GPTScript
GPTScript enables programmers to use natural language syntax and tap into OpenAI when building apps. Here's a basic GPTScript tutorial with examples for beginners. Continue Reading
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Definition
26 Jul 2024
What is a bitwise operator?
A bitwise operator is a character that represents an action taken on data at the bit level, as opposed to bytes or larger units of data. Continue Reading
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Video
19 Jul 2024
GET vs. POST: What's the difference?
POST and GET are the two most-used RESTful HTTP methods. But how well versed are you on the differences between them? Continue Reading
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Video
18 Jul 2024
How to apply the Liskov substitution principle in Java
The Liskov substitution principle is often mistaken for polymorphism and inheritance. To really understand the SOLID LSP, you must understand the nuance and distinction. Continue Reading
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Video
17 Jul 2024
How to install MySQL on Windows
Need a well-maintained, open-source, standards-based database to test your Java apps and Spring Boot microservices? Here's how to download and install the MySQL Community Edition. Continue Reading
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Tutorial
12 Jul 2024
Using generics in Typescript: An in-depth tutorial
Generic variables give the TypeScript language versatility and compile-time type safety that put it on par with Java, C# and C++. These examples show how to use TypeScript generics. Continue Reading
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Video
09 Jul 2024
Python's GIL removal is a poison pill and benefits Mojo
Developers have pleaded for 30 years for the stewards of the language to remove Python's GIL. If they do it now, it will be the end of Python. Continue Reading
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Tip
03 Jul 2024
Top benefits of the Zig programming language
Does the world really need another programming language? Yes, say developers behind Zig. Here are five of the top features Zig brings to the programming world. Continue Reading
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Tip
03 Jul 2024
How to use parallel streams in Java with virtual threads
Virtual threads in Java currently lack integration with the stream API, particularly for parallel streams. Here's how a JDK 22 preview feature addresses the problem. Continue Reading
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Video
20 Jun 2024
No-GIL Python is a mistake
Python's GIL is slated for the chopping block, and while the promise is improved performance, the reality of removing the GIL may be quite different. Continue Reading
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Blog Post
18 Jun 2024
Code a tic-tac-toe game in Java
The best way to learn to code? Code up some fun games from your childhood. Here's how to code the popular tic-tac-toe game in Java. Continue Reading
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Tip
14 Jun 2024
ORM vs. SQL: When to use each
Object relational mapping and raw SQL are two different ways to interact with relational databases. Learn when to use each of the two methods and when using both is appropriate. Continue Reading
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Tip
10 Jun 2024
5 Java ORM tools to know
ORMs are a popular method for connecting to databases from Java. Consider the tradeoffs of these ORM tools to decide which tool to run with. Continue Reading
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Tip
05 Jun 2024
Advanced Java pattern matching techniques, with examples
Dive deeper into Java pattern matching techniques with these examples that range from nested records to type inference, variables and generics. Continue Reading
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Video
30 May 2024
Constructor overloading in Java
Not every language supports method overloading, but Java always has. Here's how to perform constructor overloading in Java. Continue Reading
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Tip
28 May 2024
4 distributed ledger technology risks and how to solve them
Ready to use distributed ledger technologies for smart contracts or other transactions? Know what risks to avoid and overcome to maximize these platforms for your organization. Continue Reading
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Tip
23 May 2024
Introduction to pattern matching in Java
Pattern matching in Java helps developers better describe data structures and avoid runtime errors, while making code more readable and easier to maintain. Here's how it works. Continue Reading
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Tip
10 May 2024
An introduction to the RESTful API Modeling Language (RAML)
The RESTful API Modeling Language, or RAML, can be a powerful tool for developers looking to create an efficient, standardized API management strategy. Continue Reading
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Video
10 May 2024
Java records tutorial
Java is constantly evolving, but some changes are more significant than others. This Java records tutorial teaches you about this decade's largest language enhancement to date. Continue Reading
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Video
01 May 2024
Java's default constructor tutorial
They say you don't get anything for free, but in the world of software development, Java developers can use the default constructor without paying any price. Continue Reading
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Tip
01 May 2024
Use sealed classes in Java to control your inheritance
Need to limit the number of possible subclasses in your codebase? Here comes Java's sealed classes to your rescue. Continue Reading
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Tip
29 Apr 2024
Know how and when to use blockchain vs. distributed ledgers
Blockchain and distributed ledgers are similar but not quite synonymous. Learn their differences and how they are used, including together, for transactions and data storage. Continue Reading
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Tip
11 Apr 2024
Speed up Python and NumPy by avoiding the conversion tax
Data and memory transfers in Python come with a hidden performance tax. Here's how to use NumPy for optimal performance by avoiding jumps across a hidden line of conversions. Continue Reading
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Tip
09 Apr 2024
5 code refactoring patterns, with examples
First-time finished code is rarely elegant or maintainable. Refactoring helps keep a growing codebase maintainable and extendable over time -- as long as you know where to stop. Continue Reading
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Video
09 Apr 2024
Top REST API URL naming convention standards
There is no official REST URL naming standard. However, these 15 RESTful API naming conventions will help you create highly interoperable web services. Continue Reading
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Blog Post
08 Apr 2024
Worlds toughest core Java interview question
The trickiest Java interview question ever asked? In five words or less, explain the red 'x' the Eclipse IDE displays at the end of the provided Java code snippet. Continue Reading
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Video
04 Apr 2024
10 constructor types in Java
How many different types of Java constructors could you name? The Java spec names 10. Generic, canonical and anonymous Java constructor types just might be new to you. Continue Reading
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Video
04 Apr 2024
How Java 17 records work
Devs aren't using Java 17 records nearly enough. With the power to clean up your code and make your apps faster, Java records should be the norm and not the exception. Continue Reading
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Video
01 Apr 2024
How to use Git's 'set upstream push' command
Need to fix the 'no upstream branch' error message? Then you need to run the 'git set upstream push' command. Here's how. Continue Reading
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Tutorial
27 Mar 2024
How the saga design pattern in microservices works
When a sequence of steps must be performed to support an operation, the microservices saga design pattern is a perfect fit. Continue Reading
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Definition
25 Mar 2024
Spring Framework (Spring)
The Spring Framework (Spring) is an open source software development framework that provides infrastructure support for building Java-based applications on any deployment platform. Continue Reading
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Video
19 Mar 2024
Learn Maven tutorial for beginners
Apache Maven is the Java world's most popular build tool, and if you're a Java developer, it behooves you to learn it. This Maven tutorial will make you an expert in a hurry. Continue Reading
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Video
12 Mar 2024
Full Java constructors tutorial
How well do you know how Java constructors work? This quick Java constructors tutorial teaches you about defaults, overloading, initializing and parameterizing constructors in Java. Continue Reading
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Definition
05 Mar 2024
EAI (enterprise application integration)
Enterprise application integration (EAI) is the process of connecting an organization's business applications, services, databases and other systems into an integrating framework that facilitates communications and interoperability. Continue Reading
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Blog Post
04 Mar 2024
Best crash course to learn Jenkins from scratch
Need to learn Jenkins CI fast? This Jenkins tutorial will quickly get you up to speed on how to use the popular CI/CD tool. Continue Reading
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Blog Post
27 Feb 2024
Brackets vs braces vs parentheses: What's the difference?
Stop using the terms square brackets, round brackets and squiggly brackets. Use the terms braces, brackets and parenthesis instead. Here's the difference between them. Continue Reading
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Video
22 Feb 2024
Why we use static final in Java for constants
Java doesn't have global constants per se, but it does have static final variables. Here we explore how these two keywords make a variable constant in Java. Continue Reading
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Definition
15 Feb 2024
event handler
In programming, an event handler is a callback routine that operates asynchronously once an event takes place. Continue Reading
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Blog Post
14 Feb 2024
String to long in Java
The correct way to convert a String to long in Java is with the parseLong method of the wrapper class. The constructor conversion approach is deprecated! Use parseLong instead. Continue Reading
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Blog Post
02 Feb 2024
How to unstage a file in Git
Want to unstage a file in Git? Use the restore command. Other options to have Git remove a file from the staging index have unintended consequences you'd really rather avoid. Continue Reading
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Blog Post
01 Feb 2024
Why the Java const keyword is unimplemented
Why is the const keyword in Java not implemented? It's part of the language, but it can't be used to make a variable constant. Here's why const is included in Java, and why Java's const keyword is ... Continue Reading
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Tip
30 Jan 2024
2024 technology predictions around AI, Mojo and blockchain
Blockchain, AI, anti-competitive activity and the new programming language Mojo are sure to fill the headlines in 2024. Continue Reading
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Tip
23 Jan 2024
Debunking 5 blockchain myths and misconceptions
There's more to blockchain development than what you hear from the crypto community. Here, we debunk five common blockchain myths. Continue Reading
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Blog Post
18 Jan 2024
Finding duplicate entries in a list in Python
A common problem in computing is to find out if a list contains duplicate entries. It's also a good subject to explore various ways to solve a problem. In this case, we will see the performance ... Continue Reading
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Blog Post
17 Jan 2024
Solve the prefix sum problem with SIMDs and Vector APIs
The incubating Java Vector API gives software developers access to fast and efficient SIMD operations. Here's an example of how to solve the prefix sum problem with SIMDs and Vectors. Continue Reading
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Blog Post
11 Jan 2024
How to download and install Java 21
2024 is a great time to start working with Java, because 2023's Java 21 release has some amazing new features. Here's how to quickly download and install the Java 21 JDK. Continue Reading
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Blog Post
09 Jan 2024
Install the Eclipse IDE on Windows video tutorial
Need to install the Eclipse IDE on Windows? This quick video tutorial shows you how to install Eclipse and build your very first Java application in the popular, open-source IDE. Continue Reading
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Blog Post
09 Jan 2024
Find duplicates in a List in Java
Need to dedupe a Java list? Here are 5 simple ways to remove duplicates from a List in Java. Continue Reading
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Blog Post
08 Jan 2024
The prefix sum array problem
The prefix sum problem is often used to test a developer's mettle. Here's a simple solution to the prefix sum problem in Java that uses loops, arrays and basic Java syntax. Continue Reading
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Tip
04 Jan 2024
How the event sourcing design pattern works, with example
Learn how to control state changes as immutable events through the event sourcing model. Continue Reading
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Tip
28 Dec 2023
The benefits of using compiled regex in Python and Java
Whether you're programming in Java or Python, compiled regex can significantly speed up your text manipulation routines. Continue Reading
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Tip
27 Dec 2023
Shorter code, fewer bugs: Python's syntax is its saving grace
Is shorter code too dense and hard to parse, or is it inherently more efficient and secure? Here's why Python's compact syntax tends toward less buggy code. Continue Reading
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Blog Post
27 Dec 2023
Remove duplicates from a Java List
Deduping is a common part of data cleansing. Here are four simple ways to remove duplicates from lists in Java. Continue Reading
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Feature
19 Dec 2023
The 5 SOLID principles of object-oriented design explained
In this primer on SOLID, we'll examine the five principles this development ideology embodies, the practices they encourage and the reasons these concepts matter. Continue Reading
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Blog Post
06 Dec 2023
How the Actor Model works by example
For enterprise systems that need a flexible, asynchronous and message driven architecture, the Actor Model is often the right fit. Continue Reading
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Tip
05 Dec 2023
A primer on Java 21 virtual threads with examples
Virtual threads let developers build applications that handle potentially millions of users and ensure consistent service delivery. Here's how Java 21 virtual threads work. Continue Reading
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Answer
01 Dec 2023
11 real benefits of microservices
There's a reason why so many vendors have moved from monoliths to microservices. Here are 11 real benefits microservices bring to companies. Continue Reading
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Answer
16 Nov 2023
10 disadvantages of microservices you'll need to overcome
Not everyone is keen to adopt a cloud-native architecture, for good reasons. These common drawbacks to microservices might convince you to stick with your traditional architecture. Continue Reading
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Tip
19 Oct 2023
Understanding protocol buffers vs. JSON
Protocol buffers have some compelling advantages over JSON when it comes to sending data between internal services. But is it really a replacement for JSON? Continue Reading
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Tip
04 Oct 2023
9 tips to improve Python performance
Python performance gets a bad rap compared with languages such as Java. Use these tips to identify and fix problems in your Python code to tweak its performance. Continue Reading
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Blog Post
18 Sep 2023
Java vs. Python: Application code comparison
When you compare Java vs. Python application development in terms of simplicity, conciseness, security and performance, Java comes out on top in every category. Continue Reading
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Definition
12 Sep 2023
model-view-controller (MVC)
In programming, model-view-controller (MVC) is an architectural design pattern that organizes an application's logic into distinct layers, each of which carries out a specific set of tasks. Continue Reading
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Blog Post
01 Sep 2023
How to discard local changes in Git
Don't overlook a file or two when you attempt to remove and discard local, uncommitted changes in Git. Learn how to locally revert and remove uncommitted changes to files in Git properly. Continue Reading
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Blog Post
30 Aug 2023
10 reasons to use Kotlin
Curious about the Kotlin language? It's an excellent choice as either a companion or alternative to Java, and offers many capabilities Java programmers wish they had all along. Continue Reading
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Definition
30 Aug 2023
thread
A thread is, fundamentally, a clear, well-defined theme, subject, topic or focus. Continue Reading
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Blog Post
24 Aug 2023
How to install Jenkins on Windows
With the Jenkins installer it's incredibly easy to download and run the popular CI/CD tool. Follow these simple steps and you'll have the continuous integration server running on Windows in no time. Continue Reading
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Blog Post
21 Aug 2023
HTTP request methods explained
While there are almost 40 registered HTTP request methods, most RESTful web developers only use five of them. Here are the most important HTTP methods and examples of how to use them. Continue Reading
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Blog Post
21 Aug 2023
PUT vs POST: What's the difference?
What's the difference between PUT and POST methods? Here we compare POST versus PUT in terms of idempotence, URL usage, payloads and their use in RESTful APIs. Continue Reading
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Tutorial
11 Aug 2023
Understanding TypeScript generics
Programming languages such as Java, C# and Swift use generics to create code that's reusable and enforce type safety. In this tutorial, learn how generics in TypeScript work. Continue Reading
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Blog Post
07 Aug 2023
How to login to Docker with a Docker Hub access token
Have you been snared by Docker's "unauthorized: incorrect username or password" error when you login at the command line? Here's how to generate an access token in Docker Hub and fix it. Continue Reading