Retrieval-Augmented Generation (RAG) is a powerful approach in Artificial Intelligence that's very useful in a variety of tasks like Q&A systems, customer support, market research, personalized recommendations, and more.
A key component of RAG applications is the vector database , which helps manage and retrieve data based on semantic meaning and context.
Learn how to build a gen AI RAG application with Spring AI and the MongoDB vector database through a practical example:
Building a RAG App Using MongoDB and Spring AI
Mocking is an essential part of unit testing, and the Mockito library makes it easy to write clean and intuitive unit tests for your Java code.
Get started with mocking and improve your application tests using our Mockito guide :
Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode , for a clean learning experience:
Once the early-adopter seats are all used, the price will go up and stay at $33/year.
Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.
Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.
To learn more about Java features on Azure Container Apps, visit the documentation page .
You can also ask questions and leave feedback on the Azure Container Apps GitHub page .
Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.
Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.
With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.
Try a 14-Day Free Trial of Orkes Conductor today.
Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.
Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.
To learn more about Java features on Azure Container Apps, you can get started over on the documentation page .
And, you can also ask questions and leave feedback on the Azure Container Apps GitHub page .
Whether you're just starting out or have years of experience, Spring Boot is obviously a great choice for building a web application.
Jmix builds on this highly powerful and mature Boot stack, allowing devs to build and deliver full-stack web applications without having to code the frontend. Quite flexibly as well, from simple web GUI CRUD applications to complex enterprise solutions.
Concretely, The Jmix Platform includes a framework built on top of Spring Boot, JPA, and Vaadin , and comes with Jmix Studio, an IntelliJ IDEA plugin equipped with a suite of developer productivity tools.
The platform comes with interconnected out-of-the-box add-ons for report generation, BPM, maps, instant web app generation from a DB, and quite a bit more:
Get non-trivial analysis (and trivial, too!) suggested right inside your IDE or Git platform so you can code smart, create more value, and stay confident when you push.
Get CodiumAI for free and become part of a community of over 280,000 developers who are already experiencing improved and quicker coding.
Write code that works the way you meant it to:
CodiumAI. Meaningful Code Tests for Busy Devs
The AI Assistant to boost Boost your productivity writing unit tests - Machinet AI .
AI is all the rage these days, but for very good reason. The
highly practical coding companion, you'll get the power of
AI-assisted coding and
automated unit test generation
.
Machinet's
Unit Test AI Agent
utilizes your own project
context to create meaningful unit tests that intelligently aligns
with the behavior of the code.
And, the
AI Chat
crafts code and fixes errors with ease,
like a helpful sidekick.
Simplify Your Coding Journey with Machinet AI :
Install Machinet AI in your IntelliJ
Handling concurrency in an application can be a tricky process with many potential pitfalls . A solid grasp of the fundamentals will go a long way to help minimize these issues.
Get started with understanding multi-threaded applications with our Java Concurrency guide:
Spring 5 added support for reactive programming with the Spring WebFlux module, which has been improved upon ever since. Get started with the Reactor project basics and reactive programming in Spring Boot:
Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to
But these can also be overused and fall into some common pitfalls.
To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:
Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:
The New “REST With Spring Boot”
Yes, Spring Security can be complex, from the more advanced functionality within the Core to the deep OAuth support in the framework.
I built the security material as two full courses - Core and OAuth , to get practical with these more complex scenarios. We explore when and how to use each feature and code through it on the backing project .
You can explore the course here:
Spring Data JPA is a great way to handle the complexity of JPA with the powerful simplicity of Spring Boot .
Get started with Spring Data JPA through the guided reference course:
The Apache HTTP Client is a very robust library, suitable for both simple and advanced use cases when testing HTTP endpoints . Check out our guide covering basic request and response handling, as well as security, cookies, timeouts, and more:
A quick and practical guide to performing basic HTTP requests using Java's built-in HttpUrlConnection.2.1. Create a URL Object
Let’s create a URL object with a target URI string that accepts the JSON data via HTTP POST method:
URL url = new URL ("https://reqres.in/api/users");2.2. Open a Connection
From the above URL object, we can invoke the openConnection method to get the HttpURLConnection object.
We can’t instantiate HttpURLConnection directly, as it’s an abstract class:
HttpURLConnection con = (HttpURLConnection)url.openConnection();2.3. Set the Request Method
To send a POST request, we’ll have to set the request method property to POST:
2.4. Set the Request Content-Type Header Parameter
Set the “content-type” request header to “application/json” to send the request content in JSON form. This parameter has to be set to send the request body in JSON format.
Failing to do so, the server returns HTTP status code “400-bad request”:
con.setRequestProperty("Content-Type", "application/json");2.5. Set Response Format Type
Set the “Accept” request header to “application/json” to read the response in the desired format:
con.setRequestProperty("Accept", "application/json");2.6. Ensure the Connection Will Be Used to Send Content
To send request content, let’s enable the URLConnection object’s doOutput property to true .
Otherwise, we won’t be able to write content to the connection output stream:
After creating a custom JSON String:
String jsonInputString = "{"name": "Upendra", "job": "Programmer"}";We would need to write it:
try(OutputStream os = con.getOutputStream()) {
byte[] input = jsonInputString.getBytes("utf-8");
os.write(input, 0, input.length);
2.8. Read the Response From Input Stream
Get the input stream to read the response content. Remember to use try-with-resources to close the response stream automatically.
Read through the whole response content, and print the final response string:
try(BufferedReader br = new BufferedReader(
new InputStreamReader(con.getInputStream(), "utf-8"))) {
StringBuilder response = new StringBuilder();
String responseLine = null;
while ((responseLine = br.readLine()) != null) {
response.append(responseLine.trim());
System.out.println(response.toString());
If the response is in JSON format, use any third-party JSON parsers such as Jackson library, Gson, or org.json to parse the response.
3. Conclusion
In this article, we learned how to make a POST request with JSON content body using HttpURLConnection.
As always, the relevant code snippets can be found over on GitHub
Baeldung Pro – NPI EA (cat = Baeldung)
Baeldung Pro comes with both absolutely No-Ads as well as
finally with Dark Mode, for a clean learning experience:
Once the early-adopter seats are all used, the price will go
up and stay at $33/year.
eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
Handling concurrency in an application can be a tricky process
with many potential pitfalls. A solid grasp of the
fundamentals will go a long way to help minimize these issues.
Get started with understanding multi-threaded applications with
our Java Concurrency guide:
Partner – Orkes – NPI EA (tag = Microservices)
Modern software architecture is often broken. Slow delivery
leads to missed opportunities, innovation is stalled due to
architectural complexities, and engineering resources are
exceedingly expensive.
Orkes is the leading workflow orchestration platform
built to enable teams to transform the way they develop, connect,
and deploy applications, microservices, AI agents, and more.
With Orkes Conductor managed through Orkes Cloud, developers can
focus on building mission critical applications without worrying
about infrastructure maintenance to meet goals and, simply put,
taking new products live faster and reducing total cost of
ownership.
Try a 14-Day
Free Trial of Orkes Conductor today.
Partner – Microsoft – NPI EA (cat = Spring Boot)
Azure Container Apps is a fully managed serverless container
service that enables you to build and deploy modern,
cloud-native Java applications and microservices at scale. It
offers a simplified developer experience while providing the
flexibility and portability of containers.
Of course, Azure Container Apps has really solid support for our
ecosystem, from a number of build options, managed Java components,
native metrics, dynamic logger, and quite a bit more.
To learn more about Java features on Azure Container Apps, visit
the documentation
page.
You can also ask questions and leave feedback on the Azure
Container Apps GitHub page.
Partner – Jmix-Haulmont – NPI EA (cat= Spring Boot)
Whether you're just starting out or have years of experience,
Spring Boot is obviously a great choice for building a web
application.
Jmix builds on this highly powerful and mature Boot stack,
allowing devs to build and deliver full-stack web
applications without having to code the frontend. Quite
flexibly as well, from simple web GUI CRUD applications to complex
enterprise solutions.
Concretely, The Jmix Platform includes a framework built
on top of Spring Boot, JPA, and Vaadin, and comes with Jmix
Studio, an IntelliJ IDEA plugin equipped with a suite of
developer productivity tools.
The platform comes with interconnected out-of-the-box
add-ons for report generation, BPM, maps, instant web app
generation from a DB, and quite a bit more:
Partner – Machinet – NPI EA (cat = Baeldung)
The AI Assistant to boost Boost your productivity writing unit
tests - Machinet AI.
AI is all the rage these days, but for very good reason. The
highly practical coding companion, you'll get the power of
AI-assisted coding and automated unit test generation.
Machinet's Unit Test AI Agent utilizes your own project
context to create meaningful unit tests that intelligently aligns
with the behavior of the code.
And, the AI Chat crafts code and fixes errors with ease,
like a helpful sidekick.
Simplify Your Coding Journey with Machinet AI:
Install Machinet AI in your IntelliJ
Partner – Codium – NPI EA (cat = Testing)
Explore the secure, reliable, and high-performance Test
Execution Cloud built for scale. Right in your IDE:
CodiumAI. Meaningful Code Tests for Busy Devs
Basically, write code that works the way you meant it to.
Partner – Machinet – NPI EA (cat = Testing)
AI is all the rage these days, but for very good reason. The
highly practical coding companion, you'll get the power of
AI-assisted coding and automated unit test generation.
Machinet's Unit Test AI Agent utilizes your own project
context to create meaningful unit tests that intelligently aligns
with the behavior of the code.
Simplify Your Coding Journey with Machinet AI:
Install Machinet AI in your IntelliJ
eBook – Java Streams – NPI EA (cat=Java Streams)
Since its introduction in Java 8, the Stream API has become a
staple of Java development. The basic operations like iterating,
filtering, mapping sequences of elements are deceptively simple to
But these can also be overused and fall into some common
pitfalls.
To get a better understanding on how Streams work and how
to combine them with other language features, check out our guide
to Java Streams:
eBook – HTTP Client – NPI EA (cat=HTTP Client-Side)
The Apache HTTP Client is a very robust library, suitable
for both simple and advanced use cases when testing HTTP
endpoints. Check out our guide covering basic request and
response handling, as well as security, cookies, timeouts, and
more:
Course – LS – NPI EA (cat=REST)Course – LS – NPI (cat=HTTP Client-Side)
Get started with Spring Boot and with core Spring,
through the Learn Spring course:
the E-book
Course – RWSB – NPI EA (cat=REST)