2.17. Servlet web page redirection

发布时间 : 2025-10-25 13:33:41 UTC      

Page Views: 10 views

When the document is moved to a new location and we need to send this new location to the client, we need to use web page redirection. Of course, it may also be for load balancing, or just for simple random, all of which may involve web redirection.

The easiest way to redirect a request to another web page is to use the response object’s sendRedirect() method. The following is the definition of the method:

public void HttpServletResponse.sendRedirect(String location) throws IOException 

This method sends the response back to the browser along with the status code and the new web page location. You can also do this by putting setStatus() and setHeader() method to achieve the same effect:

.... String site = "http://www.runoob.com" ; response.setStatus(response.SC_MOVED_TEMPORARILY); response.setHeader("Location", site); .... 

2.17.1. Example

This example shows how Servlet redirects the page to another location:

package com.runoob.test; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet implementation class PageRedirect */ @WebServlet("/PageRedirect") public class PageRedirect extends HttpServlet{ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // Set response content type response.setContentType("text/html;charset=UTF-8"); // New location to redirect String site = new String("http://www.runoob.com"); response.setStatus(response.SC_MOVED_TEMPORARILY); response.setHeader("Location", site); } } 

Now let’s compile the Servlet above, and in the web.xml create the following entries in the file:

.... <servlet> <servlet-name>PageRedirectservlet-name> <servlet-class>PageRedirectservlet-class> servlet> <servlet-mapping> <servlet-name>PageRedirectservlet-name> <url-pattern>/TomcatTest/PageRedirecturl-pattern> servlet-mapping> ....    

Now call this Servlet by accessing URL http://localhost:8080/PageRedirect . This will take you to the given URL http://www.runoob.com .

《地理信息系统原理、技术与方法》  97

最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。