像静态资源一样，是否有可能服务放置在Webapp之外的JSP

Question

I am using Struts2 in my application with Tomcat.

I am serving static resource of my application by placing them outside of webapps with setting in server.xml .

Now I have to serve JSPs in same way, which are outside of my context. Is it possible? Or is there any way to achieve this?

Answer 1

You can place JSPs anywhere, but the web application should be aware of the location of the resources.

Since you didn't pointed where exactly you want to store JSPs, I couldn't tell you how to do that. I can say that resources are retrieved via URL in Java, if you can point the server to some URL where resources are stored, then you can access these resources.

If you need to learn more about how in Java accessing resources you can read Location-Independent Access to Resources .

Resources, names, and contexts

A resource is identified by a string consisting of a sequence of substrings, delimited by slashes (/), followed by a resource name. Each substring must be a valid Java identifier. The resource name is of the form shortName or shortName.extension . Both shortName and extension must be Java identifiers.

The name of a resource is independent of the Java implementation; in particular, the path separator is always a slash (/). However, the Java implementation controls the details of how the contents of the resource are mapped into a file, database, or other object containing the actual resource.

The interpretation of a resource name is relative to a class loader instance. Methods implemented by the ClassLoader class do this interpretation.

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The difference between static resources and dynamic resources:

• static resources could be run directly by browser
• dynamic resources (like JSPs) are run on server.

Don't confuse loading dynamic resources the same way as static resources, because the static resources could be returned with the response, but dynamic resources should be returned to the server.

Answer 2

JSPs get compiled into servlets (hence java classes) that are executed by a JSP container using a fairly complex life-cycle, which you can read about here: https://www.tutorialspoint.com/jsp/jsp_life_cycle.htm

So the short answer is: no. You can't serve JSP pages outside your web app, since one of the primary functions of that web app is to compile and execute JSPs.

As the other answer suggests, you can access java resources using a variety of mechanisms, but you are always going to need something that looks like a JSP container to render JSPs.

You'll have to move onto a different technology if you want to serve more of your app from something like a content delivery network.

You might look into creating a purely client side app that talks to the back end via REST, graphql, or web sockets.