How to Add Context Path to Spring Boot Application

Spring Boot provides an easy way to set the context root for your application, allowing it to be accessed via localhost:port/{app_name}. Here's how to do it:

1. Use Application Properties:

   Create a application.properties file in the src/main/resources directory and add the following properties:

   server.contextPath=/mainstay
   server.port=12378

2. Remove Custom Servlet Container Configuration:

   If you have a custom servlet container configuration in your application, such as the EmbeddedServletContainerFactory, remove it.

3. Use EmbeddedServletContainerCustomizer:

   If you need to perform post-processing on the servlet container, implement the EmbeddedServletContainerCustomizer interface and add it to your configuration. For example, to add error pages:

   @Bean
   public EmbeddedServletContainerCustomizer errorPageCustomizer() {
       return factory -> {
           ErrorPage notFoundPage = new ErrorPage(HttpStatus.NOT_FOUND, "/notfound.html");
           ErrorPage forbiddenPage = new ErrorPage(HttpStatus.FORBIDDEN, "/forbidden.html");
           factory.setErrorPages(Arrays.asList(notFoundPage, forbiddenPage));
       };
   }

4. Overriding Properties:

   You can override the default properties set in application.properties by using an external properties file or JVM parameters.

This setup will set the context path to /mainstay and have your application run on port 12378. Your application will then be accessible via localhost:12378/mainstay.