How to Change the Default Port in Spring Boot?

Last Updated : 31 May, 2024

Spring Boot framework provides a default embedded server i.e. the Tomcat server for many configuration properties to run the Spring Boot application. The application runs on the default port which is 8080. As per the application need, we can also change this default port for the embedded server. In this article, we will discuss how to change the default port number in the Spring Boot application.

What is PortNumber?

The port number helps to provide various kinds of services port number 80 always goes to the HTTP services but at a one-time only one service at a time. So, we have to change the default port number. Let's discuss how to change the port number.

We can change the default port for the embedded server in the following ways:

By Adding the configuration in the application properties of the Spring Boot project
By Implementing the WebServerFactoryCustomizer interface in the component class
Changing the configuration of VM options

First, we need to establish the spring application in our project. Spring Initializr is a web-based tool using which we can easily generate the structure of the Spring Boot project. It also provides various features for the projects expressed in a metadata model. This model allows us to configure the list of dependencies that are supported by JVM. Here, we will create the structure of an application using a spring initializer and then use an IDE to create a sample GET route. Therefore, to do this, the following steps as depicted below media sequentially as follows:

Change the Server's Port Number and Context Path

We can change the port number in application.properties file. The change can happen during development.
Also, we can change the default port number of the server along with the context path using the command line. This happens when the application is in a running state or we can say after development.

Default port number: 8080
Default Context path: '/'

Interfaces and Properties files:

We can change the default port number for embedded server in Spring Boot application using the below interfaces and properties files:

application.properties
application.yml
Command-Line Interface
WebServerFactoryCustomizer Interface
EmbeddedServletContainer Interface

Step By Step Implementation to change the default port in Spring Boot

Go to Spring Initializr
Fill in the details as per the requirements
Click on Generate which will download the starter project
Extract the zip file

Step 1: Go to Spring Initializr

Step 2: Fill in the details as per the requirements. For this application:

Project: Maven
Language: Java
Spring Boot: 2.2.8
Packaging: JAR
Java: 8
Dependencies: Spring Web

Step 3: Click on Generate which will download the starter project.

Step 4: Extract the zip file. Now open a suitable IDE and then go to File->New->Project from existing sources->Spring-boot-app and select pom.xml. Click on import changes on prompt and wait for the project to sync

Note: In the Import Project for Maven window, make sure you choose the same version of JDK which you selected while creating the project.

Method 1: By Adding the configuration in the application properties of the Spring Boot project

We need to change the port number using the application.properties file in the project structure of the spring application.

application.properties:

server.port=7000

Note: We can set the port as 0. This uses a new port whenever we restart our spring boot application.
server.port=0

Step 5: Go to src -> main -> java -> com.gfg.Spring.boot.app and run the main application.

Terminal output:

Method 2: By Implementing the WebServerFactoryCustomizer interface in the component class

Implementing the WebServerFactoryCustomizer interface in the component class. Create a server-class of the component type so that the IOC container will pick it up during the loading time and implement the interface in them. Go to src -> main -> java -> com.gfg.Spring.boot.app and create a new server.java class

server.java:

Java

@Component public class server implements WebServerFactoryCustomizer<ConfigurableWebServerFactory> {     @Override     public void customize(ConfigurableWebServerFactory factory) {           // Setting the port number         factory.setPort(1000);     } }