1： 编写一个实现Tag接口的Java类(标签处理器类)
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package
cn.gbx.web.tag;import
java.io.IOException;import
javax.servlet.http.HttpServletRequest;import
javax.servlet.jsp.JspException;import
javax.servlet.jsp.JspWriter;import
javax.servlet.jsp.tagext.TagSupport;public
class
ViewIpTag extends
TagSupport { @Override public
int
doStartTag() throws
JspException { HttpServletRequest request = (HttpServletRequest) this.pageContext.getRequest(); JspWriter out = this.pageContext.getOut(); try
{ out.print(request.getRemoteAddr()); } catch
(IOException e) { throw
new
RuntimeException(e); } return
super.doStartTag(); } } |
2：在tld文件中对标签处理器类进行描述 tld文件的位置放在WEB-INF中（/Test2/WebRoot/WEB-INF/jsptag/gbx.tld）。 文件模式可以从tomcat中查看
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<?xml version="1.0"
encoding="UTF-8"
?><taglib xmlns="http://java.sun.com/xml/ns/j2ee" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" version="2.0"> <description>A tag library exercising SimpleTag handlers.</description> <tlib-version>1.0</tlib-version> <short-name>SimpleTagLibrary</short-name> <uri>http://www.gbx.com.cn</uri> <tag> <description>show client IP</description> <!-- 注释说明 --> <name>viewIP</name> <!-- 配置的标签名 --> <tag-class>cn.gbx.web.tag.ViewIpTag</tag-class> <body-content>empty</body-content> <!-- 标签体为空 --> </tag> </taglib> |
3：在jsp页面利用taglib指令导入我们的tld文件的uri， 然后使用即可。
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<%@ page language="java"
import="java.util.*"
pageEncoding="ISO-8859-1"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP ‘1.jsp‘
starting page</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> <gbx:viewIP/> </body></html> |
原文：http://www.cnblogs.com/E-star/p/3521601.html