Spring Boot lets you to run the same application more than once on a different port number. In this chapter, you will learn about this in detail. Note that the default port number 8080.

Custom Port

In the application.properties file, we can set custom port number for the property server.port

server.port = 9090

In the application.yml file, you can find as follows −

server: 
   port: 9090

Random Port

In the application.properties file, we can set random port number for the property server.port

server.port = 0

In the application.yml file, you can find as follows −

server: 
   port: 0

Note − If the server.port number is 0 while starting the Spring Boot application, Tomcat uses the random port number.