User user=(User)session.getParameter("user");
String sex=user.getSex();
%>
2......EL鎻愪緵"."鍜?[ ]"涓ょ榪愮畻絎︽潵瀛樺彇鏁版嵁,[]鍙互璁塊棶闆嗗悎鎴栬呮暟緇勭殑鍏冪礌,Bean鐨勫睘鎬?涓嬪垪涓よ呮墍浠ｈ〃鐨勬剰鎬濇槸涓鏍風殑,浣嗘槸闇瑕佷繚璇佽鍙栧緱瀵硅薄鐨勫摢涓殑灞炴ф湁鐩稿簲鐨剆etXxx()鍜実etXxx()鏂規硶鎵嶈(鍗崇鍚圝avaBean瑙勮寖)
渚?
${sessionScope.user.set} <=======> ${session.user["sex"]}. "."鍜?[]"涔熷彲浠ユ販鍚堜嬌鐢?濡備笅:${sessionScope.shoppingCart[0].price} 榪斿洖緇撴灉涓簊hoppingCart涓涓欏圭墿鍝佺殑浠鋒牸
鍦‥L涓?瀛楃涓插嵆鍙互鐢?abc",涔熷彲浠ヤ嬌鐢?abc';
3......EL榪愮畻絎?
EL鐨勭畻鏈繍綆楃鍜孞AVA涓殑榪愮畻絎﹀ぇ鑷寸浉鍚?浼樺厛綰т篃鐩稿悓,鍖哄埆鍦ㄤ簬"+"榪愮畻絎︿笉浼氳繛鎺ュ瓧絎︿覆,鍙敤浜庡姞娉曡繍綆?
EL鍏崇郴榪愮畻絎︽湁浠ヤ笅6涓?
鍏崇郴榪愮畻絎﹀彿 璇存槑 涓句緥 緇撴灉
==鎴杄q(equal) 絳変簬 ${5==5}鎴?{5eq5} true
!=鎴杗e(not equal) 涓嶇瓑浜?${5!=5}鎴?{5eq5} false
<鎴杔t(less than) 灝忎簬 ${3!=5}鎴?{3lt5} true
>鎴杇t(great than) 澶т簬 鐣?
<=鎴杔e 灝忎簬絳変簬 鐣?
>=鎴杇e 澶т簬絳変簬 鐣?
4.......empty榪愮畻絎?
empty榪愮畻絎︿富瑕佺敤鏉ュ垽鏂兼槸鍚︿負null鎴栫┖鐨?濡傛灉涓虹┖鎴杗ull灝辮繑鍥瀟rue. 渚嬪 ${empty param.name}(param鍐呯疆瀵硅薄,鍚庨潰璁茶В)
5........浣跨敤EL浠庤〃杈句腑鍙栧緱鏁版嵁
涓庤緭鍏ユ湁鍏崇殑闅愬惈瀵硅薄鏈変袱涓?param鍜宲aramValues,浠栦滑涓や釜鏄疎L涓殑鍐呯疆瀵硅薄.涓鑸岃█,鎴戜滑鍦ㄥ彇寰楃敤鎴風殑璇鋒眰鍙傛暟鏃?鍙互鍒╃敤涓嬪垪鏂規硶:request.getParameter(String name)鍜宺equest.getParameterValues(String name),鑰屽湪EL涓彲浠ユ槸鐢╬aram鍜宲aramValues涓よ呮潵鍙栧緱鏁版嵁.浠ヤ笂鐨勪袱鍙ョ瓑浠蜂簬${param.name}鍜?{paramValues.name},鑰?{paramValues.hobbies[0]}鍙互閫氳繃鎸囧畾涓嬫爣鏉ヨ闂壒瀹氱殑鍙傛暟鐨勫?
EL鐨勫唴緗璞?
灞炴ц寖鍥?鍦‥L涓殑瀵硅薄
page pageScope
request requestScope
session sessionScope
application applicationScope
鍦‥L涓嬌鐢ㄥ唴緗璞＄殑灞炴?{requestScope.user}絳変環浜?<%=request.getParameter("user")%>. 濡傛灉涓嶆寚瀹氳寖鍥?閭ｅ氨浼氬湪涓嶅悓鐨勮寖鍥撮棿榪涜鎼滅儲.
瀵硅薄 綾?鍨?nbsp; 璇?鏄?
PageContext | javax.servlet.ServletContext |琛ㄧず姝SP鐨凱ageContext
-----------------------------------------------------------------------------------
PageScope | java.util.Map |鍙栧緱Page鑼冨洿鐨勫睘鎬у悕縐版墍瀵瑰簲鐨勫?
-------------------------------------------------------------------------------------
RequestScope | java.util.Map |鍙栧緱Request鑼冨洿鐨勫睘鎬у悕縐版墍瀵瑰簲鐨勫?
-------------------------------------------------------------------------------------
sessionScope | java.util.Map |鍙栧緱Session鑼冨洿鐨勫睘鎬у悕縐版墍瀵瑰簲鐨勫?
-------------------------------------------------------------------------------------
applicationScope | java.util.Map |鍙栧緱Application鑼冨洿鐨勫睘縐版墍瀵瑰簲鐨勫?
-------------------------------------------------------------------------------------
param | java.util.Map |濡傚悓ServletRequest.getParameter(String | |name)榪斿洖String綾誨瀷鐨勫?
----------------------------------------------------------------------------------------
paramValues | java.util.Map |濡傚悓ServletRequest.getParameterValues | |(String name)銆傝繑鍥濻tring []綾誨瀷鐨勫?
-----------------------------------------------------------------------------------------
header | java.util.Map |濡傚悓ServletRequest.getHeader(String name) | |榪斿洖String綾誨瀷鐨勫?
------------------------------------------------------------------------------------------
headerValues | java.util.Map |濡傚悓ServletRequest.getHeaders(String name) | |銆傝繑鍥濻tring []綾誨瀷鐨勫?
------------------------------------------------------------------------------------------
cookie | java.util.Map |濡傚悓HttpServletRequest.getCookies( )
------------------------------------------------------------------------------------------
initParam | java.util.Map |濡傚悓ServletContext.getInitParameter(String | |name)銆傝繑鍥濻tring綾誨瀷鐨勫?
-------------------------------------------------------------------------------------------
pageContext瀵硅薄
鎴戜滑鍙互浣跨敤 ${pageContext}鏉ュ彇寰楀叾浠栨湁鍏崇敤鎴瘋姹傛垨欏甸潰鐨勮緇嗕俊鎭備笅闈㈠垪鍑轟簡鍑犱釜姣旇緝甯哥敤鐨勯儴鍒嗐?
Expression 璇?鏄?
${pageContext.request} |鍙栧緱璇鋒眰瀵硅薄
${pageContext.session} |鍙栧緱session瀵硅薄
${pageContext.request.queryString} |鍙栧緱璇鋒眰鐨勫弬鏁板瓧絎︿覆
${pageContext.request.requestURL} |鍙栧緱璇鋒眰鐨刄RL錛屼絾涓嶅寘鎷姹備箣鍙傛暟瀛楃涓?
${pageContext.request.contextPath} |鏈嶅姟鐨剋eb application鐨勫悕縐?
${pageContext.request.method} |鍙栧緱HTTP鐨勬柟娉?GET銆丳OST)
${pageContext.request.protocol} |鍙栧緱浣跨敤鐨勫崗璁?HTTP/1.1銆丠TTP/1.0)
${pageContext.request.remoteUser} |鍙栧緱鐢ㄦ埛鍚嶇О
${pageContext.request.remoteAddr } |鍙栧緱鐢ㄦ埛鐨処P鍦板潃
${pageContext.session.new} |鍒ゆ柇session鏄惁涓烘柊鐨勶紝鎵璋撴柊鐨剆ession錛岃〃紺哄垰鐢? server浜х敓鑰宑lient灝氭湭浣跨敤
${pageContext.session.id} |鍙栧緱session鐨処D
${pageContext.servletContext.serverInfo}|鍙栧緱涓繪満绔殑鏈嶅姟淇℃伅
JSTL錛圝SP鏍囧噯鏍囩搴擄級
JSTL鐢辨牳蹇冩爣絳撅紝 <c:... > 錛寈ml瑙ｆ瀽鏍囩 <x:...>錛屽浗闄呭寲鏍囩 <fmt:....>錛屾暟鎹簱璁塊棶鏍囩 <sql:...>錛屽嚱鏁版爣絳?<fn:...>
鏍稿績鏍囩
Core
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
灞炴ц緗?
<c:set> 璁劇疆灞炴?
<c:remove> 縐婚櫎璁劇疆鐨勫睘鎬?
榪囩▼鎺у埗
<c:if test="..."> 鏉′歡鏍囩 鍙湁鍦╰est灞炴х殑鍊間負true鏄墠浼氭墽琛屾爣絳句綋
渚嬶細
<c:if test="${!(empty user.age)}">
<h1>hello </h1>
</c:if>
<c:choose>choose鍜寃hen鏄粍鍚堝湪涓璧蜂嬌鐢ㄧ殑錛屾湁鐐圭被浼間簬switch case鐨勮娉?nbsp; 銆?
<c:when test="...">when涔熸槸鏉′歡鍒ゆ柇鏍囩錛宼est灞炴х殑鍊間負true鏄墠浼氭墽琛屾爣絳句綋銆?
渚嬶細
<c:choose>
<c:when test="${param.age <18}">
<h1>you is a child <h1>
</c:when>
<c:when test="${param.age>18 and param.age <50 }">
<h1>you is a young person </h1>
</c:when>
<c:when test="${param.age>50}">
<h1>you is a old person </h1>
</c:when>
</c:choose>
<c:forEach>榪唬鏍囩
渚?
<c:forEach var="book" item="${store.books}" varStatus="status">
<h1>${book.parice} </h1>
</c:forEach>
<c:forEach begin="1" end="5" step="1">
<h1>hello </h1>
</c:forEach>
]]>