I've recently solved a problem of locating images in this community. You can look here.
However, one answer said:
Your app is a Spring Boot app. I think that you can also try to use the facilities provided by Spring Boot for serving static content. Anyway, you are doing it right now because you are using webjars for css and js libs!!! Be consistent with the tech that you are using.
This means, it's recommendable to locate the images files in /src/main/resources and not in /src/main/webapp.
How could i use the facilites that Spring Boot provides me?
Thanks
Spring Boot automatically configures production-ready settings and adds beans to your Spring project based on some dependencies that are declared in your maven/gradle build file. As long as you follow the conventions, then you do not have to do so much configuration -- "convention over configuration". For example, one convention is to load your images and static files in the resource classpath. Refer to the documentation: http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/
来源：https://stackoverflow.com/questions/32798972/java-web-application-spring-boot-locating-images