大家总是不喜欢看到<%和%>在jsp页面上，其实我们可以使用比较优雅的xml方式来表达
1
，隐含的注释
JSP语法：<%--?内容?--%>
XML语法：无
2
，变量或函数的声明
JSP语法:<%!?declaration;
[
declaration;
]
+...?%>
例如：
<%!?
???
int?
i=
0
;
int?
a,b,c;
???
Color?red=
new?
Color
(
255
,
0
,
0
)
;
???
private?static?final?
String?OK=
"ok"
;
???
public?
String?getAnswer
(){
???????
return?
OK;
???
}
%>
XML语法：
<jsp:declaration>
????
declartion;
[
declaration;
]
+...
</jsp:declaration>
例如：
<jsp:declaration>
???
int?
i=
0
;
int?
a,b,c;
???
Color?red=
new?
Color
(
255
,
0
,
0
)
;
???
private?static?final?
String?OK=
"ok"
;
???
public?
String?getAnswer
(){
???????
return?
OK;
???
}
</jsp:declaration>
3
，表达式
JSP语法：<%=expression%>
例如：
<%=Math.round
(
Math.random*
100
)
%>
XML语法：
<jsp:expression>
???
expression
</jsp:expression>
例如：
<jsp:expression>
???
Math.round
(
Math.random*
100
)
</jsp:expression>
4
，代码片断
JSP语法：<%?your?java?code?%>
例如：
<%
???
String?username=request.getParameter
(
"username"
)
.trim
()
;
???
String?password=request.getParameter
(
"password"
)
.trim
()
;
%>
XMl语法：
<jsp:scriptlet>
???
your?java?code
</jsp:scriptlet>
例如：
<jsp:scriptlet>
???
String?username=request.getParameter
(
"username"
)
.trim
()
;
???
String?password=request.getParameter
(
"password"
)
.trim
()
;
</jsp:scriptlet>
5
，指令：include
JSP语法：<%@include?file=
"relativeURL"
%>
例如：<%@include?file=
"static_head.html"
%>
XML语法：<jsp:directive.include?file=
"relativeURL"
/>
例如：<jsp:directive.include?file=
"static_head.html"
/>
6
，指令：page
JSP语法：<%@page?attribtes%>
例如：<%@page?
import
=
"java.util.HashMap"
%>
XML语法：<jsp:directive.page?attribute/>
例如：<jsp:directive.page?
import
=
"java.util.HashMap"
/>
7
,指令：taglib
JSP语法：<%@taglib?uri=
"URIForLibrary"?
prefix=
"tagPrefix"
%>
XML语法：无
对于jsp操作而言，本来就是xml格式。
下面使用xml表达方式书写一个jsp页面
example.jsp
<jsp:directive.page?contentType=
"text/html;charset=GBK"?
/>
<jsp:directive.page?
import
=
"java.util.*,java.text.*"?
/>
<jsp:declartion>
????
public?
String?getCustomDate
(
Date,date,String?pattern
){
????????
SimpleDateFormat?format=
new?
SimpleDateFormat
()
;
????????
format.applyPattern
(
pattern
)
;
????????
return?
format.format
(
date
)
;
????
}
</jsp:declartion>
<jsp:scriptlet>
????
Date?date=
(
Date
)
request.getAttribute
(
"date"
)
;
????
String?dateStr=getCustomDate
(
date,
"yyyy-MM-dd,hh:mm:ss"
)
;
</jsp:scriptlet>
<div?style=
"font-size:11pt"
>?
??
显示时间：<jsp:expression>dateStr</jsp:expression>
</div>
?
?