Java Learning 06 (first time)-JSP and Servlet

EL (Expression Language)

<%

User user= (user) Session.getattribute ("User");

Dept dept=user.getdept ();

String Departname=dept.getdname ();

%>

EL:

${sessionscope.user.dept.departname}

=${sessionscope.user.dept["Departname"]}//. Same as [], but [] can be set as a variable, convenient for dynamic value, and for the inclusion of "-" these non-alphanumeric symbols, you must use [], for example: ${user[" D-name "]} correct, ${user.d-name} error

El variable has query order: page>request>session>application, no return null found

Jsp:el:

Page:pagescope;request:requestscope;session:sessionscope;application:applicationscope

JSP standard Tag Library Jstl (part of JSP standard tag Library,java EE 5.0)

Use must import tag library in JSP page (Core library "/core" prefix= "C", and function library "/functions" prefix= "FN")

<%@ taglib uri= "Http://java.sun.com/jsp/jstl/core" prefix= "C"%>

<c:foreach var= "City" items= "${citylist}" >//c: is a prefix, foreach-loop iterates through the collection, Jstl is not in <%%>

${city}<br/>

</c:forEach>

List Number: ${fn:length (citylist)}

Core:

<c:out value=${city}>

<c:set target= "${citylist}" property= "CityName" value= "Guangzhou" >//CityList Assignment "CityName" to Guangzhou objects

${<fn:trim ("ab C")}d = "AB CD"

Java Learning 06 (first time)-JSP and Servlet