Spring Boot Port Config

Configuring Spring Boot Application Ports

Spring Boot conveniently defaults to port 8080, but you can easily change it. The primary method is using the server.port property within application.properties (or application.yml).

Using application.properties:

server.port=9090

This sets the port to 9090. Restart your application for the change to take effect.

Using application.yml:

server:
  port: 9090

This achieves the same result using YAML configuration.

Environment Variables:

Alternatively, set the SERVER_PORT environment variable. Spring Boot will automatically pick this up. The exact method depends on your operating system. For example, in Linux/macOS:

export SERVER_PORT=9090

Programmatic Configuration (Advanced):

For more complex scenarios, you can override the port programmatically within your Application class:

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.boot.web.servlet.server.ConfigurableServletWebServerFactory;

@SpringBootApplication
public class MyApplication {

    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }

    //This method configures the port programmatically
    @Bean
    public WebServerFactoryCustomizer<ConfigurableServletWebServerFactory> webServerFactoryCustomizer(){
        return factory -> factory.setPort(9090);
    }
}

Remember to choose the method best suited for your needs. For simple port changes, using application.properties or application.yml is recommended. Environment variables offer flexibility for different deployment environments. Programmatic configuration is best for advanced customization. Always restart your application after making any configuration changes.