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:

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

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1. Overview

The Spring Cloud Consul project provides easy integration with Consul for Spring Boot applications.

Consul is a tool that provides components for resolving some of the most common challenges in a micro-services architecture:

  • Service Discovery – to automatically register and unregister the network locations of service instances
  • Health Checking – to detect when a service instance is up and running
  • Distributed Configuration – to ensure all service instances use the same configuration

In this article, we’ll see how we can configure a Spring Boot application to use these features.

2. Prerequisites

To start with, it’s recommended to take a quick look at Consul and all its features.

In this article, we’re going to use a Consul agent running on localhost:8500. For more details about how to install Consul and run an agent, refer to this link.

First, we’ll need to add the spring-cloud-starter-consul-all dependency to our pom.xml:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-all</artifactId>
    <version>3.1.1</version>
</dependency>

3. Service Discovery

Let’s write our first Spring Boot application and wire up with the running Consul agent:

@SpringBootApplication
public class ServiceDiscoveryApplication {

    public static void main(String[] args) {
        new SpringApplicationBuilder(ServiceDiscoveryApplication.class)
          .web(true).run(args);
    }
}

By default, Spring Boot will try to connect to the Consul agent at localhost:8500. To use other settings, we need to update the application.yml file:

spring:
  cloud:
    consul:
      host: localhost
      port: 8500

Then, if we visit the Consul agent’s site in the browser at http://localhost:8500, we’ll see that our application was properly registered in Consul with the identifier from “${spring.application.name}:${profiles separated by comma}:${server.port}”.

To customize this identifier, we need to update the property spring.cloud.discovery.instanceId with another expression:

spring:
  application:
    name: myApp
  cloud:
    consul:
      discovery:
        instanceId: ${spring.application.name}:${random.value}

If we run the application again, we’ll see that it was registered using the identifier “MyApp” plus a random value. We need this for running multiple instances of our application on our local machine.

Finally, to disable Service Discovery, we need to set the property spring.cloud.consul.discovery.enabled to false.

3.1. Looking Up Services

We already have our application registered in Consul, but how can clients find the service endpoints? We need a discovery client service to get a running and available service from Consul.

Spring provides a DiscoveryClient API for this, which we can enable with the @EnableDiscoveryClient annotation:

@SpringBootApplication
@EnableDiscoveryClient
public class DiscoveryClientApplication {
    // ...
}

Then, we can inject the DiscoveryClient bean into our controller and access the instances:

@RestController
public class DiscoveryClientController {
 
    @Autowired
    private DiscoveryClient discoveryClient;

    public Optional<URI> serviceUrl() {
        return discoveryClient.getInstances("myApp")
          .stream()
          .findFirst() 
          .map(si -> si.getUri());
    }
}

Finally, we’ll define our application endpoints:

@GetMapping("/discoveryClient")
public String discoveryPing() throws RestClientException, 
  ServiceUnavailableException {
    URI service = serviceUrl()
      .map(s -> s.resolve("/ping"))
      .orElseThrow(ServiceUnavailableException::new);
    return restTemplate.getForEntity(service, String.class)
      .getBody();
}

@GetMapping("/ping")
public String ping() {
    return "pong";
}

The “myApp/ping” path is the Spring application name with the service endpoint. Consul will provide all available applications named “myApp”.

4. Health Checking

Consul checks the health of the service endpoints periodically.

By default, Spring implements the health endpoint to return 200 OK if the app is up. If we want to customize the endpoint we have to update the application.yml:

spring:
  cloud:
    consul:
      discovery:
        healthCheckPath: /my-health-check
        healthCheckInterval: 20s

As a result, Consul will poll the “/my-health-check” endpoint every 20 seconds.

Let’s define our custom health check service to return a FORBIDDEN status:

@GetMapping("/my-health-check")
public ResponseEntity<String> myCustomCheck() {
    String message = "Testing my healh check function";
    return new ResponseEntity<>(message, HttpStatus.FORBIDDEN);
}

If we go to the Consul agent site, we’ll see that our application is failing. To fix this, the “/my-health-check” service should return the HTTP 200 OK status code.

5. Distributed Configuration

This feature allows synchronizing the configuration among all the services. Consul will watch for any configuration changes and then trigger the update of all the services.

First, we need to add the spring-cloud-starter-consul-config dependency to our pom.xml:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-config</artifactId>
    <version>3.1.1</version>
</dependency>

We also need to move the settings of Consul and Spring application name from the application.yml file to the bootstrap.yml file which Spring loads first.

Then, we need to enable Spring Cloud Consul Config:

spring:
  application:
    name: myApp
  cloud:
    consul:
      host: localhost
      port: 8500
      config:
        enabled: true

Spring Cloud Consul Config will look for the properties in Consul at “/config/myApp”. So if we have a property called “my.prop”, we would need to create this property in the Consul agent site.

We can create the property by going to the “KEY/VALUE” section, then entering “/config/myApp/my/prop” in the “Create Key” form and “Hello World” as value. Finally, click the “Create” button.

Bear in mind that if we are using Spring profiles, we need to append the profiles next to the Spring application name. For example, if we are using the dev profile, the final path in Consul will be “/config/myApp,dev”.

Now, let’s see what our controller with the injected properties looks like:

@RestController
public class DistributedPropertiesController {

    @Value("${my.prop}")
    String value;

    @Autowired
    private MyProperties properties;

    @GetMapping("/getConfigFromValue")
    public String getConfigFromValue() {
        return value;
    }

    @GetMapping("/getConfigFromProperty")
    public String getConfigFromProperty() {
        return properties.getProp();
    }
}

And the MyProperties class:

@RefreshScope
@Configuration
@ConfigurationProperties("my")
public class MyProperties {
    private String prop;

    // standard getter, setter
}

If we run the application, the field value and properties have the same “Hello World” value from Consul.

5.1. Updating the Configuration

What about updating the configuration without restarting the Spring Boot application?

If we go back to the Consul agent site and we update the property “/config/myApp/my/prop” with another value like “New Hello World”, then the field value will not change and the field properties will have been updated to “New Hello World” as expected.

This is because the field properties is a MyProperties class has the @RefreshScope annotation. All beans annotated with the @RefreshScope annotation will be refreshed after configuration changes.

In real life, we should not have the properties directly in Consul, but we should store them persistently somewhere. We can do this using a Config Server.

6. Conclusion

In this article, we’ve seen how to set up our Spring Boot applications to work with Consul for Service Discovery purposes, customize the health checking rules and share a distributed configuration.

We’ve also introduced a number of approaches for the clients to invoke these registered services.

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)
announcement - icon

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)
announcement - icon

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)
eBook – eBook Guide Spring Cloud – NPI (cat=Cloud/Spring Cloud)