Spring Boot WAR 部署

Question

How can I control in my Spring 2.1.4 Boot application (packaged as a WAR) whether I am creating a servlet 3.1 or 4.0 web application. Normally, when using a web.xml web application descriptor, the attributes on the web-app would announce the version of the spec being used. In a Spring WebApplicationInitializer application without a web.xml (which is my case), there is no such advertisement.

Is it just a matter of using only the servlet 3.1 features and deploying them to a container and hope that it works?

Answer 1

The web.xml file is optional since Servlet 3 and Java EE 6 where annotations such as @WebServlet , @WebFilter , @WebListener were introduced.

However, there is no way to declare this information outside the web.xml using the WebApplicationInitializer so you have to include the file anyway and specify the version.

Answer 2

After more than a year of posting this question I discovered that maven makes such determination by the presence of the specific API declared as a dependency. For example if you have the javax.servlet:javax.servlet-api:4.0.1 dependency in your Pom file maven will assume a servlet 4.0 container. I believe Spring boot does not support this but I think it should. As a sidenote the M2eclipse plug-in also works this way