|
tag文件只是以tag为后缀名的文本文件。除了jsp页面指令外，其他JSP元素都可以出现在tag文件中 页面引用格式
<%@ taglib prefix="ui" tagdir="/WEB-INF/tags" %>
tagdir：用于指定tag文件目录，当页面使用<ui:xxxx>进，会查找该目录下对应的xxxx.tag文件。 prefix：指定使用时标签前缀
使用格式 <ui:xxxx></ui:xxxx> 例子：<ui:tagDemo><ui:tagDemo>
tag文件添加属性：当tag文件需要引用页面传入参数时，就需要在tag文件中填加属性 定义属性格式 <%@ attribute name="attributename" required="true" type="com.myapp.util.ListPage" %> name(必须)：属性名 required(必须)：指定是否必须传 type(可选)：指定属性类型。 tag文件获得传入参数值 String attributename=(String) pageContext.getAttribute("attributename"); 或者在jsp元素中使用${pageScope.attributename} 也可使用<jsp:doBody/> 获取引用页面标签内的body内容。
下面是示例： tagDemo.tag -------------------------------------------------------------------------------------------- <%@tag pageEncoding="UTF-8" isELIgnored="false" %>
<!--body-content="empty"表明使用标签时，标签内不能有内容 -->
<%@ taglib prefix="c" uri="http://java./jsp/jstl/core" %> <%@ attribute name="listPage" required="true" type="test.ListPage" %> <%@ attribute name="url" required="true"%> <%@ attribute name="appender" required="false"%> <%@ attribute name="color" required="false" %> <table width="400" cellpadding="5" bgcolor="${pageScope.color}"> <tr> <td> <jsp:doBody/> </td> </tr> </table> <c:if test="${not empty listPage.authors}"> <c:choose> <c:when test="${not empty appender}"> <c:set var="myPath" value="${url}${appender}page="/> </c:when> <c:otherwise> <c:set var="myPath" value="${url}"/> </c:otherwise> </c:choose> <c:if test="${listPage.hasNext}"><a href='<c:url value="${myPath}${listPage.nextPage}"/>'>下一页</a></c:if> <c:if test="${listPage.hasPrev}"><a href='<c:url value="${myPath}${listPage.prevPage}"/>'>上一页</a></c:if> (${listPage.currentPage}/<a href='<c:url value="${myPath}${listPage.totalPage}"/>'>${listPage.totalPage}</a>页)<br/> <c:if test="${listPage.totalPage >= 3}"> 快速翻页:<input name="page" maxlength="4" size="3" value="1" format="*N"/> <anchor>GO <go method="post" href="<c:url value='${myPath}$(page)'/>"></go> </anchor><br/> </c:if> </c:if> -------------------------------------------------------------------------------------------- 使用页面tagDemo.jsp <PRE class=html name="code"> <%@page import="test.Author"%> <%@page import="test.ListPage"%> <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <%@ taglib prefix="tags" tagdir="/WEB-INF/tags" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>标签文件简介示例</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <% ListPage listPage=new ListPage(); listPage.setHasNext(true); listPage.setHasPrev(false); listPage.setTotalPage(10); listPage.setCurrentPage(1); listPage.setNextPage(2); listPage.setPrevPage(10); List<Author> atuhors=new ArrayList<Author>(); Author author=new Author(); author.setId(1); author.setName("liao"); atuhors.add(author); listPage.setAuthors(atuhors); %> <tags:tagDemo url="tagDemo.jsp?page=" listPage="<%=listPage%>" color="red">这是我传入的Body内容</tags:tagDemo> </body> </html> </PRE><BR> <PRE></PRE> -------------------------------------------------------------------------------------------- 下面是两个实体类 ListPage.java public class ListPage { private boolean hasNext; private boolean hasPrev; private Integer totalPage; private Integer currentPage; private Integer nextPage; private Integer prevPage; private List<Author> authors; public List<Author> getAuthors() { return authors; } public void setAuthors(List<Author> authors) { ... } -------------------------------------------------------------------------------------------- Author.java public class Author { private Integer id; private String name; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } -------------------------------------------------------------------------------------------- 做这个demo需要导入jstl的标签库 jstl.jar和standard.jar |
|
|
