out

, and 

out

 is subsequently re assigned to refer to that previous (nesting) stream. Such 

nested streams are always buffered, and require explicit flushing to a nesting stream or 

discarding of their contents.

If the 

initial

out

JspWriter

 object is buffered, then depending upon the value of the 

autoFlush

 attribute of the 

page

 directive, the content of that buffer will either be 

automatically flushed out to the 

ServletResponse

 output stream to obviate overflow, 

or an exception shall be thrown to signal buffer overflow. If the 

initial

out

JspWriter

 is 

unbuffered, then content written to it will be passed directly through to the 

ServletResponse

 output stream.

A JSP page can also describe what should happen when some specific 

events

 occur. In JSP 

1.1, the only events that can be described are initialization and destruction of the page; these 

are described using  well known method names  in declaration elements (see page 73). 

Future specifications will likely define more events as well as a more structured mechanism 

for describing the actions to take.

2.6

Template Text Semantics

The semantics of 

template (or uninterpreted) Text

 is very simple: the template text is passed 

through to the current 

out

JspWriter

 implicit object, after applying the substitutions of 

Section 2.4,  Quoting and Escape Conventions .

2.7

Directives

Directives are messages to the JSP container. In JSP 1.1, directives have this syntax:

<%@ 

directive

{ attr= value  }* 

%>

There may be optional white space after the  <%@  and before  %> .

This syntax is easy to type and concise but it is not XML compatible. Section 7 describes the 

mapping of directives into XML elements.

Directives do not produce any output into the current 

out

 stream.

The remainder of this section describes the standard directives that are available on all 

conforming JSP 1.1 implementations.

Chapter 2

Standard Syntax and Semantics

42