轉發與重定向學習代碼
阿新 • • 發佈：2018-04-18
轉發與重定向學習代碼html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>用戶登錄</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body> <form action="/day07/LoginServlet" method="post"> <table border="1" align="center"> <caption>用戶登錄</caption> <tr> <th>用戶名</th> <td><input type="text" name="username"/></td> </tr> <tr> <td colspan="2" align="center"> <input type="submit" value="提交"/> ???? <input type="reset" value="重填"/> </td> </tr> </table> </form> </body> </html>
java
LoginServlet
import java.io.IOException; import java.util.HashMap; import java.util.Map; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import cn.itcast.web.domain.IpCheckBean; public class LoginServlet extends HttpServlet { //key為IP,value為歸屬地 private Map<String,String> map = new HashMap<String,String>(); public void init() throws ServletException { //在用戶第一次訪問前加載IP和歸屬地，不存在多線程安全問題 map.put("192.168.12.222","北京"); map.put("192.168.11.122","上海"); map.put("192.168.11.50","深圳"); map.put("192.168.11.33","佛山"); map.put("192.168.11.44","珠海"); map.put("127.0.0.1","北京"); } public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); //IP String ip = request.getRemoteAddr(); IpCheckBean ipCheckBean = new IpCheckBean(); //歸屬地 String address = ipCheckBean.check(ip,map); //用戶名 String username = request.getParameter("username"); //將信息綁定到ServletContext對象中 ServletContext context = this.getServletContext(); context.setAttribute("username",username); context.setAttribute("ip",ip); context.setAttribute("address",address); /*轉發到ShowServlet context .getRequestDispatcher("/ShowServlet") .forward(request,response); */ //重定向到ShowServlet 是走get方法 response.sendRedirect("/day07/ShowServlet"); } }
ShowServlet
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class ShowServlet extends HttpServlet { public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { ServletContext context = this.getServletContext(); response.setContentType("text/html;charset=UTF-8"); PrintWriter pw = response.getWriter(); pw.write("歡迎："+context.getAttribute("username")+"光臨<br/>"); pw.write("你的IP是："+context.getAttribute("ip")+"<br/>"); pw.write("歸屬地："+context.getAttribute("address")+"<br/>"); } public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { this.doPost(request,response); } }
ListServlet
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ListServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
String username = (String) request.getAttribute("USERNAME");
response.setContentType("text/html;charset=UTF-8");
response.getWriter().write("歡迎"+username+"光臨");
}
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
String username = (String) request.getAttribute("USERNAME");
response.setContentType("text/html;charset=UTF-8");
response.getWriter().write("歡迎"+username+"光臨");
}
}轉發與重定向學習代碼