package cn.itcast.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.PageContext;
import javax.servlet.jsp.tagext.Tag;
public class ViewIPTag implements Tag {
private PageContext pageContext;
public int doStartTag() throws JspException {
HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();//獲取頁面Servlet中 request 和out 對象
JspWriter out = pageContext.getOut();
String ip = request.getRemoteAddr(); //獲取用戶IP地址
try {
out.write(ip);
} catch (IOException e) {
throw new RuntimeException(e);
}
return 0;
}
public int doEndTag() throws JspException {
return 0;
}
public Tag getParent() {
return null;
}
public void release() {
}
public void setPageContext(PageContext arg0) {
this.pageContext = arg0;//PageContext獲取用戶request out 等對象
}
public void setParent(Tag arg0) {
}
}
?xml version="1.0" encoding="UTF-8" ?>
taglib xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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>/itcast/uri>
tag>
name>viewIP/name> !-- 為標簽處理器類配一個標簽名 -->
tag-class>cn.itcast.web.tag.ViewIPTag/tag-class>
body-content>empty/body-content>
/tag>
/taglib>
%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
%@taglib uri="/itcast" prefix="itcast" %>
!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
html>
head>
title>輸出客戶機的IP/title>
/head>
body>
您的IP是：itcast:viewIP/>
/body>
/html>
