WEB-INF folder

Question

Can we place all class files in the WEB-INF folder and all the JSP's outside?

Answer 1

The class files must place into WEB-INF/classes folder and JSP files must place within a distinct folder.
Yes! Else the web server/ application server can’t access classes and jsp files.
The java class files can be placed in WEB-INF/lib or WEB-INF/classes. However it is recommended to put the class files in WEB-INF/classes. The server will load files from the class path so it will not matter where the class exist.
Yes, class files are private resources, so you may store class in WEB-INF/classes folder.
JSP and HTML files must be placed outside.
Class files inside the web-inf can’t be access by browsers, while the JSP files are meant for accessible by browsers so that it can be strictly place outside the web-inf only.
A structure of web app is given below:
web (this folder is reachable from www)
Store all JSP and HTML files here
WEB-INF (this folder is not reachable)
classes (store classes here, classes you are using in jsp
lib (store 3rd party jars)   
i.)Class files -: they must be in WEB-INFclasses directory or you can package the files as JAR and place in WEB-INFlib
ii.) JSP files - : Depends how you design your arch. If you have controller who can forward requests to JSPs, can keep them under the WEB-INF directory also. If not, you have to put them outside the WEB-INF.
The JMS API is a messaging standard which allows application components based on Java 2 Platform, Enterprise Edition (J2EE) to create, receive, send, and read messages. It allows distributed communication which is lightly coupled, asynchronous and reliable.