The Layers:
web layer: com.truman.web/servlet/controller
service layer: com.truman.service //This is a Interface package
com.truman.service.impl
dao layer: com.truman.dao // This is a Interface package
com.truman.dao.impl
bean: com.truman.pojo/entity/domain/bean
util : com.truman.utils
test : Test
Three Layers of JavaEE Projects
原文：https://www.cnblogs.com/nedrain/p/13189124.html