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1 7 JSTL 1.1 JSTL JavaServer Pages Standard Tag Library 1.1 JSTL JCP(Java Community Process) Java Web Web JSTL EL Web Java (Scripting) JSTL URL U18N XML SQL JSTL JSTL JSTL 1.1 简介 7-2 核心标签库 (Core tag library) 7-3 I18N 格式标签库 (I18N-capable formatting tags library) 7-4 SQL 标签库 (SQL tag library) 7-5 XML 标签库 (XML tag library) 7-6 函数标签库 (Functions tag library)

2 126 JSTL JSTL 1.1 JavaServer Pages Standard Tag Library (1.1 ) JSP JSTL XML 7-1 JSTL 1 (Core tag library) 2 I18N (I18N-capable formatting tag library) 3 SQL (SQL tag library) 4 XML (XML tag library) 5 (Functions tag library) 7-1 JSTL URI c <c:out> I18N fmt <fmt:formatdate> SQL sql <sql:query> XML xml <x:forbach> fn <fn:split> JSTL EL(Expression Language) JSP <%= userlist.getuser().getphonenumber() %> JSTL <c_rt:out value="<%= userlist.getuser( ).getphonenumber( ) %>" /> JSTL EL <c:out value="${userlist.user.phonenumber}" /> Java Script Java JSTL 1.1 JSTL 1.1 Servlet 2.4 JSP 2.0 Container JSTL Apache Jakarta Project JSTL 1.1 JSTL jakarta-taglibs-standard-current.zip 7-1

$7-1 JSTL 1.1 127 7-1 jakarta-taglibs-standard-1.1.0-b1 lib jstl.jar standard.jar Tomcat WEB-INF\lib JSP JSTL.jar tld WEB-INF lib jstl.jar standard.jar old-dependencies JSTL 1.0 JSTL 1.$

3 7-1 JSTL jakarta-taglibs-standard b1 lib jstl.jar standard.jar Tomcat WEB-INF\lib JSP JSTL.jar tld WEB-INF lib jstl.jar standard.jar old-dependencies JSTL 1.0 JSTL 1.1 tld TLD JSTL 1.0 TLD c-1_0.tld c-1_0-rt.tld HelloJSTL.jsp HelloJSTL.jsp page contenttype="text/html;charset=gb2312" %> taglib prefix="c" uri=" %> <html> <head> <title> JSTL </title> </head> <body> <c:out value=" JSTL "/> </br> <c:out value="${header['user-agent']}"/> <c:set var="a" value="david O'Davies" /> <c:out value="david O'Davies" escapexml="true"/> </body> </html> HelloJSTL.jsp (Core) EL header JSP JSTL taglib prefix="c" uri=" %> JSTL (prefix)

128 JSTL 1.1 c uri http://java.sun.com/jsp/jstl/core JSTL 1.0 uri http://java.sun.com/jstl/corejstl 1.1 jsp/ JSTL 1.1 JSTL 1.0 1.1 uri http://java.sun.com/jstl/core JSTL 1.

4 128 JSTL 1.1 c uri JSTL 1.0 uri jsp/ JSTL 1.1 JSTL uri JSTL 1.0 out value ${header['user-agent']} User-Agent <c:out value=" JSTL " /> <c:out value="${header['user-agent']}" /> HelloJSTL.jsp HelloJSTL.jsp taglib uri web.xml uri web.xml <web-app> <jsp-config> <taglib> <taglib-uri> <taglib-location>/web-inf/tld/c.tld</taglib-location> </taglib> </jsp-config> </web-app> <taglib-uri> URI <taglib-location> TLD <%@ taglib %> <%@ taglib prefix="c" uri=" %> JSTL 1.1 VS. JSTL 1.0 JSTL 1.0 JSTL 1.1

5 7-1 JSTL (1) EL JSTL 1.0 EL JSP 2.0 JSTL 1.1 EL JSTL EL (2) JSTL 1.0 EL RT JSTL 1.1 EL RT EL Expression Language RT Scriptlet Java EL (3) JSTL 1.1 ( functions) fn:contains fn:containsignorecase fn:endswith fn:indexof fn:join fn:length fn:replace fn:split fn:startswith fn:substring JSTL 1.1 B Changes standard-examples jakarta-taglibs-standard-current.zip ( 7-1) standard-examples.war Tomcat webapps Tomcat webapps standard-examples IE URL standard-examples 7-3 JSTL General Purpose Tags Conditional Tags Iterator Tags Import Tags I18N & Formatting Tags XML Tags SQL Tags Functions Tag Library Validators Miscellaneous

6 130 JSTL standard-examples JSTL 7-2 (Core tag library) (Core) URL out set remove catch if Core choose when otherwise foreach fortokens

7 7-2 (Core tag library) 131 Core URL import param url param redirect param JSP JSTL prefix taglib %> uri taglib prefix="c" uri=" %> JSTL JSTL JSTL <c:out> <c:set> <c:remove> <c:catch> <c:out> <c:out> <%= scripting-language %> Hello! <c:out value="${username}" /> 1 (body) <c:out value="value" [escapexml="{true false}"] [default="defaultvalue"] /> 2 <c:out value="value" [escapexml="{true false}"]> default value </c:out> EL value Y Object default value null default Y Object escapexml < < Y boolean true

8 132 JSTL 1.1 EL EL Y attribute = "${ }" N Null value null default default <c:out> < > & > ' " < &<c:out> escapexml fasle Entity < < > > ' " & & <c:out value="hello JSP 2.0!! " /> <c:out value="${ }" /> <c:out value="${ param.data }" default="no Data" /> <c:out value="<p> </p>" /> <c:out value="<p> </p>" escapexml="false" /> 1 Hello JSP 2.0!! data data data null No Data 4<p> </p> 5 <c:set> <c:set> JSP JavaBean 1 valuescope varname <c:set value="value" var="varname" [scope="{ page request session application }"]/> 2 scope varname <c:set var="varname" [scope="{ page request session application }"]> </c:set>

9 7-2 (Core tag library) value target <c:set value="value" target="target" property="propertyname" /> 4 target <c:set target="target" property="propertyname"> </c:set> EL value Y Object var N String scope target property Null var JSP N String page JavaBean java.util.map Y Object target Y String 3 4 target null target java.util.map JavaBean value null 1 var scope scope PageContext.removeAttribute(varName, scope) scope PageContext.removeAttribute(varName) 3 target Map Map.remove(property) target JavaBean property null <c:set> var scope scope="session" session <c:set> scope Page var scope scope="${ourscope}" var="${username}" <c:set var="number" scope="session" value="${1 + 1}"/>

10 134 JSTL number <c:set> value value <c:set> </c:set> <c:set var="number" scope="session"> <c:out value="${1+1}" /> </c:set> <c:out value="${1+1}" /> 2 <%=1+1%> <c:set> (body) value <c:set> body <c:set var="number" scope="session"> </c:set> number <c:set var="number" scope="request" value="${1 + 1}" /> <c:set var="number" scope="session" /> ${3 + 5} </c:set> <c:set var="number" scope="request" value="${ param.number }" /> <c:set target="user" property="name" value="${ param.username}" /> 1 2 Request number 2 8 Session number 3 ${param.number} null Request number ${param.number} null ${param.number} Request number 4 ${param.username} null User(JavaBean) name null null ${param.username} User(JavaBean) name ( setter ) 3. ${param.number} null Request number <c:remove> <c:remove> <c:remove var="varname" [scope="{ page request session application }"] /> EL var scope N String var JSP N String page

11 7-2 (Core tag library) 135 <c:remove> var scope <c:remove var="number" scope="session" /> number Session scope <c:remove> Page Request Session Application number <c:set> <c:remove> Core_set_remove.jsp Core_set_remove.jsp page contenttype="text/html;charset=gb2312" %> taglib prefix="c" uri=" %> <html> <head> <title>ch7 - Core_set_remove.jsp</title> </head> <body> <h2><c:out value="<c:set> <c:remove> " /></h2> <c:set scope="page" var="number"> <c:out value="${1+1}"/> </c:set> <c:set scope="request" var="number"> <%= 3 %> </c:set> <c:set scope="session" var="number"> 4 </c:set> <table border="1" width="30%"> <tr> <th>pagescope.number</th> <td><c:out value="${pagescope.number}" default="no Data" /></td> </tr> <tr> <th>requestscope.number</th> <td><c:out value="${requestscope.number}" default="no Data" /></td>

12 136 JSTL 1.1 </tr> <tr> <th>sessionscope.number</th> <td><c:out value="${sessionscope.number}" default="no Data" /></td> </tr> </table></br> <c:out value='<c:remove var="number" scope="page" />'/> <c:remove var="number" scope="page" /> <table border="1" width="30%"> <tr> <th>pagescope.number</th> <td><c:out value="${pagescope.number}" default="no Data" /></td> </tr> <tr> <th>requestscope.number</th> <td><c:out value="${requestscope.number}" default="no Data" /></td> </tr> <tr> <th>sessionscope.number</th> <td><c:out value="${sessionscope.number}" default="no Data" /></td> </tr> </table></br> <c:out value='<c:remove var="number" />'/> <c:remove var="number" /> <table border="1" width="30%"> <tr> <th>pagescope.number</th> <td><c:out value="${pagescope.number}" default="no Data" /></td> </tr> <tr> <th>requestscope.number</th> <td><c:out value="${requestscope.number}" default="no Data" /></td> </tr> <tr> <th>sessionscope.number</th> <td><c:out value="${sessionscope.number}" default="no Data" /></td> </tr> </table> </body> </html> Page Request Session number <c:remove var="number" scope="page" Page/> number <c:remove var="number" /> number Core_set_remove.jsp 7-4

13 7-2 (Core tag library) 137 <c:catch> 7-4 Core_set_remove.jsp <c:catch> <c:catch [var="varname"] > </c:catch> EL var N String <c:catch> <c:catch> </c:catch> varname <c:catch var="message"> // </c:catch>

138 JSTL 1.1 <c:catch> </c:catch> <c:catch> </c:catch> Core_catch.jsp <c:catch> Core_catch.jsp <%@ page contenttype="text/html;charset=gb2312 " %> <%@ taglib prefix="c" uri="http://java.sun.

14 138 JSTL 1.1 <c:catch> </c:catch> <c:catch> </c:catch> Core_catch.jsp <c:catch> Core_catch.jsp page contenttype="text/html;charset=gb2312 " %> taglib prefix="c" uri=" %> <html> <head> <title>ch7 - Core_catch.jsp</title> </head> <body> <h2><c:out value="<c:catch> " /></h2> <c:catch var="error_message"> <% String eformat = "not number"; int i = Integer.parseInt(eFormat); %> </c:catch> ${error_message} </body> </html> <c:catch> error_message <c:out> Core_catch.jsp <c:catch> <c:catch> </c:catch> 7-6

7-2 (Core tag library) 139 7-6 Core_catch.

15 7-2 (Core tag library) Core_catch.jsp <c:catch> </c:catch> <c:if> <c:choose> <c:when> <c:otherwise> <c:if> <c:if> 1 (body) <c:if test="testcondition" var="varname" [scope="{page request session application}"]/> 2 <c:if test="testcondition" [var="varname"] [scope="{page request session application}"]> </c:if>

16 140 JSTL 1.1 EL test var true false Y boolean test true false N String scope var JSP N String page <c:if> test test true false${param.username param.username = = 'admin'} admin true admin false <c:if test="${param.username = = 'admin' }"> ADMIN!! //body </c:if> admin "ADMIN!! "< body "ADMIN!! //body " <c:if> JSP (Scriptlet) JSP HTML test <c:if> var scope<c:if> var scope var var scope Core_if.jsp Core_if.jsp <%@ page contenttype="text/html;charset=gb2312 " %> <%@ taglib prefix="c" uri=" <html> <head> <title>ch7 - Core_if.jsp</title> </head> <body> <h2><c:out value="<c:if> " /></h2> <c:if test="${param.username == 'Admin'}" var="condition" scope="page"> Admin </c:if></br>

$7-2 (Core tag library) 141 : ${condition} </body> </html> username Admin condition true pagescope condition JSTL condition ${condition} ${pagescope.condition} Core_if.$

17 7-2 (Core tag library) 141 : ${condition} </body> </html> username Admin condition true pagescope condition JSTL condition ${condition} ${pagescope.condition} Core_if.jsp 7-7 Core_if.jsp?username=Admin <c:choose> 7-7 Core_if.jsp <c:choose> <c:when> <c:otherwise> <c:choose> ( <when> <otherwise> ) </c:choose> <c:choose> 1 <c:when> 0 <c:otherwise>

18 142 JSTL 1.1 <c:when> <c:otherwise> <c:choose> <c:choose> <c:when> </c:when> <c:otherwise> </c:otherwise> </c:choose> <c:when> <c:when> when <c:when test="testcondition" > </c:when> EL test true false Y boolean <c:when> <c:choose> </c:choose> <c:choose> <c:when> <c:otherwise> <c:when> test test true false <c:otherwise> <c:choose> <c:when> <c:otherwise>

19 7-2 (Core tag library) 143 <c:otherwise> </c:otherwise> <c:otherwise> <c:choose> </c:choose> <c:choose> <c:otherwise> <c:choose> <c:when> test true <c:otherwise> <c:choose> <c:when> <c:otherwise> <c:choose> <c:when test="${condition1}"> condition1 true </c:when> <c:when test="${ condition2}"> condition2 true </c:when> <c:otherwise> condition1 condition2 false </c:otherwise> </c:choose> condition1 truecondition1 true condition1 false condition2 true condition2 truefalse condition1 condition2false condition1 condition2 true "condition1 true" <c:choose> <c:when> <c:when>

20 144 JSTL (Iterate) <c:foreach> <c:fortokens> <c:foreach> <c:foreach> (Collection) <c:foreach> 1 <c:foreach [var="varname"] items="collection" [varstatus="varstatusname"] </c:foreach> [begin="begin"] [end="end"] [step="step"]> 2 <c:foreach [var="varname"] [varstatus="varstatusname"] begin="begin" </c:foreach> end="end" [step="step"]> var EL N String items Y Arrays Collection Iterator Enumeration Map String varstatus N String begin Y int 0 end Y int step Y int 1 begin begin 0 end begin

21 7-2 (Core tag library) 145 step step 0 Null items null begin items items Core_forEach.jsp Core_forEach.jsp <%@ page contenttype="text/html;charset=gb2312 " %> <%@ taglib prefix="c" uri=" %> <html> <head> <title>ch7 - Core_forEach.jsp</title> </head> <body> <h2><c:out value="<c:foreach> " /></h2> <% %> String atts[] = new String [5]; atts[0]="hello"; atts[1]="this"; atts[2]="is"; atts[3]="a"; atts[4]="pen"; request.setattribute("atts", atts); <c:foreach items="${atts}" var="item" > ${item}</br> </c:foreach> </body> </html> atts Request <c:foreach> items var <c:out> item 7-8

22 146 JSTL Core_forEach.jsp varname <c:foreach> varname ${item} </c:foreach> <c:foreach items="${atts}" var="item" > </c:foreach> ${item}</br> ${item} <c:foreach> J2SE ArrayList List LinkedList Vector Stack Set java.util.map HashMap Hashtable Properties Provider Attributes <c:foreach> begin end step begin ( 0) end step Core_forEach1.jsp <%@ page contenttype="text/html;charset=gb2312" %> <%@ taglib prefix="c" uri=" %> <html> <head> <title>ch7 - Core_forEach1.jsp</title> </head> <body> <h2><c:out value="<c:foreach> begin end step " /></h2> <%

$setattribute("atts", atts); <c:foreach items="${atts}" var="item" begin="1" end="4" step="2" > ${item}</br> </c:foreach> </body> </html> <c:foreach> atts 2 5 atts[1] atts[3] 7-9 7-9 Core_forEach1.$

23 7-2 (Core tag library) 147 %> String atts[] = new String [5]; atts[0]="hello"; atts[1]="this"; atts[2]="is"; atts[3]="a"; atts[4]="pen"; request.setattribute("atts", atts); <c:foreach items="${atts}" var="item" begin="1" end="4" step="2" > ${item}</br> </c:foreach> </body> </html> <c:foreach> atts 2 5 atts[1] atts[3] Core_forEach1.jsp begin end step <% int atts[] = {1,2,3,4,5,6,7,8,9,10}; request.setattribute("atts", atts); %> <c:foreach items="${atts}" var="item" begin="0" end="9" step="1" > ${item}</br> </c:foreach> begin end step 7-4

24 148 JSTL begin end step (1) begin end (2) begin end (3) end end (4) <c:foreach> 7-4 items items begin end Core_forEach2.jsp <%@ page contenttype="text/html;charset=gb2312" %> <%@ taglib prefix="c" uri=" %> <html> <head> <title>ch7 - Core_forEach2.jsp</title> </head> <body> <h2><c:out value="<c:foreach> " /></h2> <c:foreach begin="1" end="10" var="item" > ${item}</br> </c:foreach> </body> </html> begin end 1 10

25 7-2 (Core tag library) 149 item Core_forEach2.jsp Core_forEach2.jsp step step step 2 <c:foreach> varstatus varstatus="s" s varstatus index count first last index number count number first boolean last boolean

26 150 JSTL 1.1 varstatus Core_forEach3.jsp page contenttype="text/html;charset=gb2312" %> taglib prefix="c" uri=" %> <html> <head> <title>ch7 - Core_forEach3.jsp</title> </head> <body> <h2><c:out value="<c:foreach> varstatus " /></h2> <% String atts[] = new String [5]; atts[0]="hello"; atts[1]="this"; atts[2]="is"; atts[3]="a"; atts[4]="pen"; request.setattribute("atts", atts); %> <c:foreach items="${atts}" var="item"varstatus="s"> <h2><c:out value="${item}"/></h2> index ${s.index}</br> count ${s.count}</br> first ${s.first}</br> last ${s.last}</br> </c:foreach> </body> </html> 7-12 <c:fortokens> <c:fortokens> <c:fortokens items="stringoftokens" delims="delimiters" [var="varname"] [varstatus="varstatusname"] [begin="begin"] [end="end"] [step="step"]> </c:fortokens>

7-2 (Core tag library) 151 7-12 Core_forEach3.

27 7-2 (Core tag library) Core_forEach3.jsp var EL N String items Y String delims N String varstatus N String begin Y int 0 end Y int step Y int 1 begin begin 0 end begin step step 0 Null items null begin items

28 152 JSTL 1.1 <c:fortokens> begin end step var varstatus <c:foreach> items delims items delims items <c:fortokens> <c:fortokens items="a,b,c,d,e" delims="," var="item" > ${item} </c:fortokens> ABCDE, 5 5 A,B,C,D,E, items EL <% String phonenumber = " "; request.setattribute("userphone", phonenumber); %> <c:fortokens items="${userphone}" delims="-" var="item" > ${item} </c:fortokens> item delims <c:fortokens items="a,b;c-d,e" delims=",;-" var="item" > ${item} </c:fortokens> ABCDEdelims <c:foreach> <c:foreach items="a,b,c,d,e" var="item" > ${item} </c:foreach> ABCDE <c:foreach> delims <c:foreach> <c:foreach>, <c:fortokens> delims, <c:for <c:foreach> URL JSTL URL <c:import> <c:redirect> <c:url> url

29 7-2 (Core tag library) 153 <c:import> <c:import> JSP JSP Action <jsp:include> <jsp:include> web application <c:import> web application web application 1 <c:import url="url" [context="context"] [var="varname"] [scope="{page request session application}"] [charencoding="charencoding"]> </c:import> 2 <c:import url="url" [context="context"] varreader="varreadername" [charencoding="charencoding"]> </c:import> EL url Y String context Container / web Y String var ( String ) N String scope var JSP N String Page charencoding Y String varreader ( Reader ) N String Null url null JspException <c:import> url <c:import url=" />

30 154 JSTL 1.1 <c:import> <c:import> FTP FTP ftp.javaworld.com.tw data.txt <c:import url="ftp://ftp.cse.yzu.edu.tw/data.txt" /> Hello.jsp <c:import> webapps <c:import> <c:import url="hello.jsp" /> / web Tomcat webapps hello.txt webapps/examples/images context examples hello.txt JSP <c:import url="images/hello.txt" /> web context web others others jsp index.html <c:import url="/jsp/index.html" context="/others" /> web server.xml <Context> crosscontext trueothers web server.xml <Context path="/others" docbase="others" debug="0" reloadable="true" crosscontext="true"/> <c:import> var scope var String varname scope varname <c:import url="/images/hello.txt" var="s" scope="session" /> <c:import> <c:param>

31 7-2 (Core tag library) 155 name value EL name Y String value Y String EL <c:import url=" > <c:param name="test" value="1234" /> </c:import> <c:import> <c:param> Core_import.jsp Core_imported.jsp Core_import.jsp <%@ page contenttype="text/html;charset=gb2312" %> <%@ taglib prefix="c" uri=" %> <html> <head> <title>ch7 - Core_import.jsp</title> </head> <body> <h2><c:out value="<c:import> " /></h2> <c:set var="input1" value=" Core_imported.jsp " scope="request"/> core_imported.jsp <hr/> <c:import url="core_imported.jsp"charencoding="gb2312" > <c:param name="input2" value="<c:param> Core_imported.jsp "/> </c:import><hr/> ${output1} </body> </html> <c:set> <c:param>

32 156 JSTL 1.1 Core_imported.jsp page contenttype="text/html;charset=gb2312" %> taglib prefix="c" uri=" %> taglib prefix="fmt" uri=" %> <html> <head> <title>ch7 - Core_imported.jsp</title> </head> <body> <fmt:requestencoding value="gb2312" /> <c:set var="output1" value=" Core_import.jsp " scope="request"/> ${input1}</br> <c:out value="${param.input2}" escapexml="true" /> </body> </html> Core_imported.jsp Core_import.jsp input1 ${input1} input2 ${param.input2} <c:set> Core_import.jsp <c:param> <c:param> Core_import.jsp 7-13 <c:url> <c:url> URL 7-13 Core_import.jsp

33 7-2 (Core tag library) <c:url value="value" [context="context"] [var="varname"] [scope="{page request session application}"] /> 2 (Query String) <c:url value="value" [context="context"] [var="varname"] [scope="{page request session application}"] > <c:param> </c:url> EL value URL Y String context Container web / Y String var scope ( String ) N String var JSP N String Page <c:url value=" " > <c:param name="param" value="value"/> </c:url> <c:url> <c:param> HTML <a> <a href=" <c:url value=" " > <c:param name="param" value="value"/> </c:url>"> Java </a> <c:url> context var scope context <c:import> web <c:url> var varname <c:url> web <c:url> <c:url> web <img src="<c:url value="/images/code.gif" />" />

34 158 JSTL 1.1 image code.gif <c:redirect> <c:redirect> JSP 1 <c:redirect url="url" [context="context"] /> 2 (Query String) <c:redirect url="url" [context="context"] > <c:param> </c:redirect > EL url Y String context Container web / Y String url <c:redirect url=" /> context web /others /jsp/index.html <c:redirect url="/jsp/index.html" context="/others" /> <c:redirect> <c:param> Core_redirect.jsp <%@ page contenttype="text/html;charset=gb2312" %> <%@ taglib prefix="c" uri=" %> <html>

35 <head> <title>ch7 - Core_redirect.jsp</title> </head> <body> 7-2 (Core tag library) 159 <h2><c:out value="<c:redirect> " /></h2> <c:redirect url=" <c:param name="param" value="value"/> </c:redirect> <c:out value="!!!" /> </body> </html> Core_redirect.jsp

设计模式 Design Patterns

设计模式 Design Patterns 丁勇 Email:18442056@QQ.com 学习目标理解核心标签库理解国际化和格式化标签理解 SQL 标签库 JSTL Server Pages 标准标签库 (JSTL) 包含的各种标签可用于 JSP 页面中 JSTL 的优点提供一组标准标签可用于编写各种动态 JSP 页面用于访问数据库有条件地执行代码和支持国际化核心标签库核心标签库包含以下标签 : 核心标签库通用标签条件标签