There are two main ways to change the port in the Embedded Tomcat in a Spring Boot Application.

Modify application.properties

First you can try the application.properties file in the /resources folder:

server.port = 8090

Modify a VM option

The second way, if you want to avoid modifying any files and checking in something that you only need on your local, you can use a vm arg:

Go to Run -> Edit Configurations -> VM options

-Dserver.port=8090

Additionally, if you need more information you can view the following blog post here: Changing the port on a Spring Boot Application

By default spring boot uses port 8080, BUT you can change the port just by adding the following code line in your main() like this:

System.getProperties().put( "server.port", *YOUR_PORT_NUMBER_GOES_HERE* );  

e.g

@SpringBootApplication
public class MyClass {
public static void main(String[] args) {
    System.getProperties().put( "server.port", 8181 );  //8181 port is set here
    SpringApplication.run(MyClass.class, args);
}

OR

You can configure it in your application.properties file like so:

server.port=8181

If you DON'T have an application.properties file in your spring-boot application, you can go ahead and create one. Right-click on the src/java/resources folder and go to New-> Other-> General and choose 'File' then name as: application.properties

Any other configurations you might need are listed here https://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html. These properties are also configured in the application.properties file.