java server pages converted to servlet?

Question

i read that inside the webserver a jsp page is converted to a servlet. When does this conversion happen ? Do i have to run a specific command ?

Answer 1

It's done at runtime, when the JSP is invoked for the first time. Some web servers also come with a JSP compiler allowing to do that at build time, which has two advantages :

1. It allows detecting JSP syntax errors at build time rather than runtime
2. It avoids the first invocation time penalty (it takes some time compiling JSP to Java and then Java to bytecode).