问题
Scriptlets let you insert arbitrary code into servlet's _jspService method.
Can anyone explain this statement with an example containing a block of code?
I am aware about syntactical stuff of JSP and Servlets, what I need to know is
- In what context arbitrary code is used?
_jspService() is a method of JSP life cycle then,
- What does it mean by servlet's method?
回答1:
A JSP is in fact transformed by the container into a Java class extending HttpServlet, that class is then compiled and executed exactly as a hand-coded servlet would be.
The code you have into the JSP is transformed into Java code that constitutes the _jspService method of the generated servlet. So, for example
<html>
<% String foo = "hello"; out.println(foo); %>
is transformed by the container, into something like
void _jspService(JspWriter out) {
out.println("<html>");
String foo = "hello"; out.println(foo);
}
So, whatever code you write into your scriptlets (arbitrary code) ends up in the _jspService method of the servlet created by the container from the JSP.
来源：https://stackoverflow.com/questions/32679523/scriptlets-inserts-arbitrary-code-into-servlets-jspservice-method