I found yet one more way to get obtain a 404 with Eclipse, Spring Boot hello world application, and Maven. If you choose to 'Run on Server' or Maven install, that won't work. As the answer by Sengar already indicates, Run as, Maven Configuration, with the goal set to spring-boot:run, that will work. This answer is only to say that 'Run as Java Application' also works. But more importantly, 'Run on Server' won't, even though the war is exploded in the .metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/ directory.