如何在运行时动态创建，注册和映射servlet

Question

I have a small spring boot java application project, to implement Proxy approach using Servlets, which contains a maven dependency on a project which provides me a UtilityServlet which I am extending in the TestServlet of my project and registering the servlet mapping using @Bean and @Configuration annotations. My application is working fine with this approach, but i have new use case.

I am trying to be able to modularize/ parameterize the application config.

What I want is to be able to create, register and map servlets at runtime during application startup based on the number of URL patterns that are required to be mapped passed as parameter to application. For eg

servletUrl.properties contain following 3 url mappings:

servlet.url1=/servlet1/*
target.url1=/target1/
servlet.url2=/servlet2/*
target.url2=/target2/
servlet.url3=/servlet3/*
target.url3=/target3/

On the basis of above mappings I want that on application startup, application recognizes 3 url mappings in the property file and create and register 3 different servlets extending UtilityServlet, one for each mapping.

Is there a way to accomplish something like this, Spring solution would be preferred but not necessarily a deal breaker. Thanks in advance guys

Answer 1

Let your single Servlet implementation call a routing class.

The Router reads the config file and sets up different handler classes depending on its content.

When calls come from the Servlet, they get routed on calling-url to the correct handler-class.

For instance, your base servlet can have a base url mapping of 'api'. When calls come in with say 'api/target1?param=etc' you just route on 'target1' to the correct handler.