Note: This article is about Play Framework 1.2.x and might not apply to Play 2.x projects.
The other day I had to convert some code from C to Java. This code runs some pretty simple calculations, using a few classes as data-holders, and running a few thousand iterations. I had to get this working as part of the backend for a Play Framework web application.
In C the code would run blindingly fast, and return the results within 10-20 milliseconds. All good!
After a couple of hours of converting the code and fixing the pointer/reference/initialization oddities between Java and C, I got the code running. Well, more like walking, or lazily sauntering along. The Java code took 4 seconds to run. I know Java is perceived to be slow, but my experience with it was telling me that there is no way it should be so slow.