test1.jsp======================= <a href ="test.jsp?p=fuck">跳转到test2</a> test2.jsp======================= <%@ page language="java" import="java.util.*" pageEncoding="gb2312"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; out.println("basePath:"+basePath); out.println("<br/>"); out.println("getContextPath:"+request.getContextPath()); out.println("<br/>"); out.println("getServletPath:"+request.getServletPath()); out.println("<br/>"); out.println("getRequestURI:"+request.getRequestURI()); out.println("<br/>"); out.println("getRequestURL:"+request.getRequestURL()); out.println("<br/>"); out.println("getRealPath:"+request.getRealPath("/")); out.println("<br/>"); out.println("getServletContext().getRealPath:"+getServletContext().getRealPath("/")); out.println("<br/>"); out.println("getQueryString:"+request.getQueryString()); %>
显示结果
basePath:http://localhost:8080/test/
getContextPath:/test
getServletPath:/test.jsp
getRequestURI:/test/test.jsp
getRequestURL:http://localhost:8080/test/test.jsp
getRealPath:D:\Tomcat 6.0\webapps\test\
getServletContext().getRealPath:D:\Tomcat 6.0\webapps\test\
getQueryString:p=fuck
在一些应用中，未登录用户请求了必须登录的资源时，提示用户登录，此时要记住用户访问的当前页面的URL，当他登录成功后根据记住的URL跳回用户最后访问的页面：
String lastAccessUrl = request.getRequestURL() + "?" + request.getQueryString();
假定你的web application 名称为news,你在浏览器中输入请求路径：
http://localhost:8080/news/main/list.jsp
则执行下面向行代码后打印出如下结果：
1、 System.out.println(request.getContextPath());
打印结果：/news
2、System.out.println(request.getServletPath());
打印结果：/main/list.JSP
3、 System.out.println(request.getRequestURI());
打印结果：/news/main/list.JSp
4、 System.out.println(request.getRealPath("/"));
打印结果：F:\tomcat 6.0\webapps\news\test
