Lightweight alternative to Jetty
Usually Jetty is mentioned as the lightweight alternative when it comes to servlet containers like Tomcat and App Servers like Glassfish.
I want to run a RESTful service on CloudFoundry. Using jetty-runner
java -jar target/dependency/jetty-runner.jar target/*.war
works kind of fine, except I kind of run into problems running Jetty 9.1.3 (current stable) /w Java 8. So I contributed a patch to fix this issue and some other minor code cleanup patches. Hereby I saw the code of Jetty which was not in a shape I hoped it to be...
Well I just don't want to entrust my enterprise app to Jetty and looking for alternatives. Also with 5.x MB, jetty-runner.jar is still huge. I managed to strip it down to 1.6 MB and I was still able to run my app. So an even more lightweight approach is feasible.
Is there a lightweight version of GlassFish or Tomcat. I just need the servlet-api.jar (v3.1) being run in a web server context. No JSP, no websocket-server, no other Voodoo.
Answer
Undertow is a flexible performant web server written in java, providing both blocking and non-blocking API’s based on NIO.
Undertow has a composition based architecture that allows you to build a web server by combining small single purpose handlers. The gives you the flexibility to choose between a full Java EE servlet 3.1 container, or a low level non-blocking handler, to anything in between.
Undertow is extremely lightweight, with the Undertow core jar coming in at under 1Mb. It is lightweight at runtime too, with a simple embedded server using less than 4Mb of heap space.
Link to official site.