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Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:

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Once the early-adopter seats are all used, the price will go up and stay at $33/year.

Partner – Microsoft – NPI EA (cat = Baeldung)
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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 – Microsoft – NPI EA (cat= Spring Boot)
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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.

Partner – Orkes – NPI EA (cat=Spring)
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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 – Orkes – NPI EA (tag=Microservices)
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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.

eBook – Guide Spring Cloud – NPI EA (cat=Spring Cloud)
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Let's get started with a Microservice Architecture with Spring Cloud:

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eBook – Mockito – NPI EA (tag = Mockito)
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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:

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eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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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.

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eBook – Reactive – NPI EA (cat=Reactive)
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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:

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eBook – Java Streams – NPI EA (cat=Java Streams)
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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 use.

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:

>> Join Pro and download the eBook

eBook – Jackson – NPI EA (cat=Jackson)
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Do JSON right with Jackson

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eBook – HTTP Client – NPI EA (cat=Http Client-Side)
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Get the most out of the Apache HTTP Client

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Get Started with Apache Maven:

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eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

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eBook – RwS – NPI EA (cat=Spring MVC)
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Building a REST API with Spring?

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Course – LS – NPI EA (cat=Jackson)
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Get started with Spring and Spring Boot, through the Learn Spring course:

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Course – RWSB – NPI EA (cat=REST)
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Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:

>> The New “REST With Spring Boot”

Course – LSS – NPI EA (cat=Spring Security)
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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:

>> Learn Spring Security

Course – All Access – NPI EA (cat= Spring)
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All Access is finally out, with all of my Spring courses. Learn JUnit is out as well, and Learn Maven is coming fast. And, of course, quite a bit more affordable. Finally.

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Course – LSD – NPI EA (tag=Spring Data JPA)
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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:

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Partner – LambdaTest – NPI EA (cat=Testing)
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End-to-end testing is a very useful method to make sure that your application works as intended. This highlights issues in the overall functionality of the software, that the unit and integration test stages may miss.

Playwright is an easy-to-use, but powerful tool that automates end-to-end testing, and supports all modern browsers and platforms.

When coupled with LambdaTest (an AI-powered cloud-based test execution platform) it can be further scaled to run the Playwright scripts in parallel across 3000+ browser and device combinations:

>> Automated End-to-End Testing With Playwright

Course – Spring Sale 2025 – NPI EA (cat= Baeldung)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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Course – Spring Sale 2025 – NPI (cat=Baeldung)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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 1. Overview

In this tutorial, we’ll discuss how to use environment variables in Spring Boot’s application.properties and application.yml. Then, we’ll learn how to refer to those properties in the code.

Further reading:

Properties with Spring and Spring Boot

Tutorial for how to work with properties files and property values in Spring.

Using application.yml vs application.properties in Spring Boot

Spring Boot supports both .properties and YAML. We explore the differences between injecting properties, and how to provide multiple configurations.

Environment Variable Prefixes in Spring Boot

Learn how to use a prefix for environment variables with Spring Boot.

2. Use Environment Variables in the application.properties File

Let’s define a global environment variable called JAVA_HOME with the value “C:\Program Files\Java\jdk-11.0.14“.

To use this variable in Spring Boot’s application.properties, we need to surround it with braces:

java.home=${JAVA_HOME}

We can also use the system properties in the same way. For instance, on Windows, an OS property is defined by default:

environment.name=${OS}

It’s also possible to combine several variable values. Let’s define another environment variable, HELLO_BAELDUNG, with the value “Hello Baeldung“. We can now concatenate our two variables:

baeldung.presentation=${HELLO_BAELDUNG}. Java is installed in the folder: ${JAVA_HOME}

The property baeldung.presentation now contains the following text: “Hello Baeldung. Java is installed in the folder: C:\Program Files\Java\jdk-11.0.14“.

This way, our properties have different values depending on the environment.

3. Use Our Environment-Specific Properties in Code

Given that we start a Spring context, we’ll now see how we can inject the property value into our code.

3.1. Inject the Value With @Value

First, we can use the @Value annotation. @Value handles setter, constructor, and field injections:

@Value("${baeldung.presentation}")
private String baeldungPresentation;

3.2. Get It From the Spring Environment

We can also get the value of the property via Spring’s Environment. We’ll need to autowire it:

@Autowired
private Environment environment;

The property value can now be retrieved, thanks to the getProperty() method:

environment.getProperty("baeldung.presentation")

3.3. Group Properties With @ConfigurationProperties

The @ConfigurationProperties annotation is very useful if we want to group properties together. We’ll define a Component that will gather all properties with a given prefix, in our case baeldung. Then, we can define a setter for each property. The name of the setter is the rest of the name of the property. In our case, we have only one, called presentation:

@Component
@ConfigurationProperties(prefix = "baeldung")
public class BaeldungProperties {

    private String presentation;

    public String getPresentation() {
        return presentation;
    }

    public void setPresentation(String presentation) {
        this.presentation = presentation;
    }
}

We can now autowire a BaeldungProperties object:

@Autowired
private BaeldungProperties baeldungProperties;

Finally, to get the value of a specific property, we need to use the corresponding getter:

baeldungProperties.getPresentation()

4. Use Environment Variable in the application.yml File

Just like application.properties, application.yml is a configuration file that defines various properties and settings for an application. To use an environment variable, we need to declare its name in the property placeholder.

Let’s see an example application.yml file with a property placeholder and the variable name:

spring:
  datasource:
    url: ${DATABASE_URL}

The example above shows we’re trying to import a database URL inside our Spring Boot application. The ${DATABASE_URL} expression prompts Spring Boot to look for an environment variable with the name DATABASE_URL.

To define an environment variable in application.yml, we must start with a dollar sign, followed by an opening curly brace, the name of the environment variable, and a closing curly brace. All these combined make up the property placeholder and the environment variable name.

Furthermore, we can use the environment-specific property in our code, just like we do with application.properties. We can inject the value using the @Value annotation. Also, we can use the Environment class. Finally, we can use the @ConfigurationProperties annotation.

5. Loading Multiple Properties From an Environment Variable

Starting with Spring Boot 3.5.0-M2, we can now load multiple configuration properties from a single environment variable. Traditionally, we often define separate environment variables for each property. Now,  we can consolidate related properties into a single environment variable.

For example, let’s define an environment variable named DATABASE_CONFIG:

export DATABASE_CONFIG="
DATABASE_URL=jdbc:h2:mem:testdb 
USERNAME=sa
PASSWORD=password
"

The format above mirrors the key-value pair structure used in application.properties files.

Alternatively, we can define the properties in the environment variable using the YAML format:

export DATABASE_CONFIG=$(cat <<EOF
DATABASE_URL: jdbc:h2:mem:testdb
USERNAME: sa
PASSWORD: password
EOF
)

Spring Boot supports both the properties format and the YAML format content within an environment variable when using the spring.config.import property.

Next, let’s reference the environment variable in the application.properties file by using the spring.config.import property:

spring.config.import=env:DATABASE_CONFIG

Here, we use the env keyword with the environment variable name, prompting Spring Boot to load properties from the specified environment variable.

Finally, let’s use some of the properties in our database configuration as a placeholder:

spring.datasource.url=${DATABASE_URL}
spring.datasource.username=${USERNAME}
spring.datasource.password=${PASSWORD}

In the code above, we use the properties defined in the DATABASE_CONFIG environment, avoiding defining each property as a separate environment variable.

6. Conclusion

In this article, we learned how to define properties with different values depending on the environment and use them in the code. Additionally, we saw how to define environment variables in application.properties and application.yml files. Finally, we looked at examples of injecting the defined properties into the example code.

The code backing this article is available on GitHub. Once you're logged in as a Baeldung Pro Member, start learning and coding on the project.
Baeldung Pro – NPI EA (cat = Baeldung)
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Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:

>> Explore a clean Baeldung

Once the early-adopter seats are all used, the price will go up and stay at $33/year.

Partner – Microsoft – NPI EA (cat = Spring Boot)
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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 – Orkes – NPI EA (cat = Spring)
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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 – Orkes – NPI EA (tag = Microservices)
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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.

eBook – HTTP Client – NPI EA (cat=HTTP Client-Side)
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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:

>> Download the eBook

eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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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:

>> Download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
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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 use.

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:

>> Join Pro and download the eBook

eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

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Course – LS – NPI EA (cat=REST)

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Get started with Spring Boot and with core Spring, through the Learn Spring course:

>> CHECK OUT THE COURSE

Course – Spring Sale 2025 – NPI EA (cat= Baeldung)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

>> EXPLORE ACCESS NOW

Course – Spring Sale 2025 – NPI (All)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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Partner – Microsoft – NPI (cat=Spring)
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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.

eBook Jackson – NPI EA – 3 (cat = Jackson)