How to change the default port of Spring Boot application

Hussein TerekMarch 20th, 2018Last Updated: March 19th, 2018

1 13 1 minute read

By default, Spring Boot applications run on an embedded Tomcat via port 8080. In order to change the default port, you just need to modify server.port attribute which is automatically read at runtime by Spring Boot applications.

In this tutorial, we provide the common ways of modifying server.port attribute.

1- application.properties

Create application.properties file under src/main/resources and define server.port attribute inside it:

application.properties

server.port=9090

2- EmbeddedServletContainerCustomizer

You can customize the properties of the default servlet container through implementing the EmbeddedServletContainerCustomizer interface as the following:

package com.programmer.gate;
 
import org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer;
import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer;
 
public class CustomContainer implements EmbeddedServletContainerCustomizer {
    @Override
    public void customize(ConfigurableEmbeddedServletContainer container) {
        container.setPort(9090);
    }
}

The port defined inside the CustomContainer always overrides the value defined inside application.properties.

3- Command line

The third way is to set the port explicitly when starting up the application through the command line, you can do this in 2 different ways:

java -Dserver.port=9090 -jar executable.jar
java -jar executable.jar –server.port=9090

The port defined using this way overrides any other ports defined through other ways.

Published on Java Code Geeks with permission by Hussein Terek, partner at our JCG program. See the original article here: How to change the default port of Spring Boot application

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