How to change the Server port in Spring Boot

In a Spring Boot application, the default web server port is set to 8080. However, there are various scenarios where you might need to change this port, such as avoiding conflicts with other applications or adhering to specific deployment requirements. This tutorial will guide you through multiple methods to change the default web server port in a Spring Boot application, ensuring you have the flexibility to choose the approach that best fits your needs.

Set the Port in application.properties or application.yml

The simplest way to change the port is by setting the server.port property in the application.properties or application.yml file.

For example, to change the default port to 8081:

server.port=8081

Or, using application.yml:

server:
  port: 8081

Use Command Line Arguments to set the Web Port

You can also change the port by passing a command-line argument when starting your Spring Boot application. For example:

java -jar your-app.jar --server.port=8081

Change the Port Porgrammatically

Another programmatic approach is to implement the WebServerFactoryCustomizer interface.

import org.springframework.boot.web.server.ConfigurableWebServerFactory;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.stereotype.Component;

@Component
public class ServerPortCustomizer implements WebServerFactoryCustomizer<ConfigurableWebServerFactory> {
    @Override
    public void customize(ConfigurableWebServerFactory factory) {
        factory.setPort(8081);
    }
}

Alternatively, you can use as Type the Factory to your Web Server. This is useful if you wantto apply some properties which are specific to your Web Server:

import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.stereotype.Component;

@Component
public class TomcatCustomizer implements WebServerFactoryCustomizer<TomcatServletWebServerFactory> {

    @Override
    public void customize(TomcatServletWebServerFactory factory) {

        factory.setPort(8080);
    }
}

Using different profiles

Finally, if your application uses multiple profiles, you can define the Web Server port in each profile of your choice. For example:

application-dev.properties:

server.port=8081

application-prod.properties:

server.port=8082

Activate the profile when starting the application:

java -jar your-app.jar --spring.profiles.active=dev

Conclusion

This article provided guidance on how to change the default HTTP Port of Tomcat Web Server either through configuration or programmatically.

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