{"id":2444,"date":"2020-10-29T15:24:50","date_gmt":"2020-10-29T07:24:50","guid":{"rendered":"http:\/\/admin.evshou.com\/?p=2444"},"modified":"2020-10-29T15:24:50","modified_gmt":"2020-10-29T07:24:50","slug":"2020javaweb%e6%95%99%e7%a8%8b%ef%bc%9ajsp%e4%b9%8bjstl","status":"publish","type":"post","link":"https:\/\/www.9713job.com\/?p=2444","title":{"rendered":"2020javaweb\u6559\u7a0b\uff1ajsp\u4e4bJSTL"},"content":{"rendered":"

2020javaweb\u6559\u7a0b\uff1ajsp\u4e4bJSTL<\/h3>\n

\u4ec0\u4e48\u662fJSTL\uff1f<\/span><\/strong>
\n\u5168\u79f0Java Server Pages Standard Tag Library,<\/span>JSP\u6807\u51c6\u6807\u7b7e\u5e93<\/span>,\u4ee3\u66ffjsp\u9875\u9762\u7684\u811a\u672c\uff0c\u5b9e\u73b0\u903b\u8f91\u63a7\u5236<\/p>\n

JSTL\u7684\u4f5c\u7528\uff1a<\/span><\/strong><\/p>\n

\u5b9e\u73b0JSP\u9875\u9762\u4e2d\u903b\u8f91\u5904\u7406\u3002\u5982\u5224\u65ad\uff0c \u5faa\u73af\u7b49\uff1b
\n<\/p>\n

\u4e0b\u8f7dJSTL\u5e93\uff0chttp:\/\/archive.apache.org\/dist\/jakarta\/taglibs\/standard\/binaries\/<\/a><\/span><\/p>\n

\u628ajstl.jar\u3001standard.jar\u653e\u5165WEB-INF\/lib\u76ee\u5f55\u4e0b<\/p>\n

\u4f7f\u7528JSTL<\/span><\/strong><\/p>\n

\u5fc5\u987b\u5728JSP\u9875\u9762\u6dfb\u52a0tablib\u6307\u4ee4\u5e93<\/span><\/p>\n

<%@taglib prefix=\"c\" uri=\"http:\/\/java.sun.com\/jsp\/jstl\/core\" %><\/pre>\n
\u5e38\u7528\u6807\u7b7e\u4ecb\u7ecd<\/span><\/p>\n
<%-- var\u58f0\u660e\u53d8\u91cf\u5e76\u8d4b\u503c value  \u5355\u4e2a\u503c --%>\r\n<c:<\/span>set var=\"a\" value=\"5\" \/>\r\n<%--\u53d6\u503c--%>\r\n<c:<\/span>out value=\"${a}\" \/>\r\n<%-- \u4ece\u4f5c\u7528\u57df\u79fb\u9664a --%>\r\n<c:<\/span>remove var=\"a\" \/>\r\n<%-- \u6253\u5370a \u5982\u6ca1\u6709\u5219\u6253\u5370\u9ed8\u8ba4\u503c --%>\r\n<c:<\/span>out value=\"${a}\" default=\"\u6ca1\u6709\u503c\" \/>\r\n\r\n<%-- \u8fd0\u7b97\u7684\u503c \u7528 EL\u8868\u8fbe\u5f0f\uff0c\u9ed8\u8ba4\u5b58\u5728pageContext\u4f5c\u7528\u57df\u91cc scope\u53ef\u4ee5\u6307\u5b9a\u5728\u54ea\u4e2a\u4f5c\u7528\u57df<\/span> --%>\r\n<c:<\/span>set  var=\"b\" value=\"${1+1}\" scope<\/span>=\"request\" \/>\r\n<c:<\/span>out value=\"${b}\" \/><\/pre>\n
if\u548cchoose\u6807\u7b7e<\/span><\/strong><\/p>\n
<%-- if --%><\/span>\r\n<c:if test=\"${5>2}\">\r\n    EL\u8868\u8fbe\u5f0f\u8fd0\u7b97\u7b26\u7ed3\u679c\u4e3atrue\u5219\u663e\u793a<\/span>\r\n<\/c:if>\r\n<br>\r\n<%-- Choose --%><\/span>\r\n<c:set var=\"score\" value=\"90\" \/>\r\n<c:choose><\/span>\r\n    <c:when test=\"${score>=60}\">\u53ca\u683c<\/c:when><\/span>\r\n    <c:when test=\"${score<60}\">\u4e0d\u53ca\u683c<\/c:when>\r\n<%--    \u4e0d\u6ee1\u8db3\u6761\u4ef6\u5219\u8fd9\u91cc\uff0c \u7b49\u4ef7 else--%>\r\n    <>\u4f18\u79c0<\/c:otherwise><\/span>\r\n<\/c:choose><\/span><\/pre>\n
foreach\u6807\u7b7e<\/span><\/strong><\/p>\n
<%--var\u53d8\u91cf begin\u4ece\u51e0\u5f00\u59cb end\u5230\u51e0\u7ed3\u675f step\u8fed\u4ee3--%>\r\n<c:forEach var=\"i\" begin=\"1\" end=\"50\" step=\"1\">\r\n    ${i}\r\n<\/c:forEach>\r\n\r\n<%-- \u5bf9\u8c61foreach --%>\r\n<%\r\n    List<Users> list=new ArrayList<Users>();\r\n    list.add(new Users(\"admin\",\"admin\"));\r\n    list.add(new Users(\"admin888\",\"admin888\"));\r\n    list.add(new Users(\"admin999\",\"admin999\"));\r\n    pageContext.setAttribute(\"list\",list);<\/span>\r\n%>\r\n<%-- items\u96c6\u5408 var\u53d8\u91cf --%>\r\n<c:forEach var=\"users\" items=\"${list}\"><\/span>\r\n    ${users.username}\r\n<\/c:forEach><\/pre>\n
url\u6807\u7b7e<\/span><\/strong><\/p>\n
<%-- var\u53d8\u91cf value \u8981\u8df3\u8f6c\u5230\u54ea\u4e2a\u5730\u5740 --%>\r\n<c:url var=\"test\" value=\"test.jsp\"\/>\r\n<a href=\"${test}\">\u8df3\u8f6c<\/a><\/pre>\n","protected":false},"excerpt":{"rendered":"
2020javaweb\u6559\u7a0b\uff1ajsp\u4e4bJSTL \u4ec0\u4e48\u662fJSTL\uff1f \u5168\u79f0Java Server Pages Sta […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-2444","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2444","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2444"}],"version-history":[{"count":1,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2444\/revisions"}],"predecessor-version":[{"id":2445,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2444\/revisions\/2445"}],"wp:attachment":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2444"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2444"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2444"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}