標籤:row writer ... lang ons servlet 地址欄 部署 throw
通過繼承HttpServlet抽象類別,功能更強大。
通過HttpServlet方法開發Servlet需要重寫doGet和doPost方法。這是目前用的最多的一種方法。
如: class MyHttpServlet extends HttpServlet
1 package cn.servlet; 2 3 import java.io.IOException; 4 import java.io.PrintWriter; 5 6 import javax.servlet.ServletException; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse;10 11 public class MyHttpServlet extends HttpServlet {12 //在HttpServlet中,設計者對post提交和get提交分別處理 13 //<form action="提交給?" method="post|get">,預設是get提交 14 //其實,doGet和doPost最終也去調用了Servlet介面中的service()方法15 public void doGet(HttpServletRequest request, HttpServletResponse response)16 throws ServletException, IOException {17 18 PrintWriter out = response.getWriter();19 out.print("<h1>I am doGet()..................</h1>");20 }21 22 23 public void doPost(HttpServletRequest request, HttpServletResponse response)24 throws ServletException, IOException {25 PrintWriter out = response.getWriter();26 out.print("<h1>I am doPost().................</h1>");27 }28 }
部署:
<serlvet> <servlet-name>MyHttpServlet</servlet-name> <servlet-class>cn.servlet.MyHttpServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>MyHttpServlet</servlet-name> <url-pattern>/servlet/MyHttpServlet</url-pattern> </servlet-mapping>
由結果可知,預設調用的是doGet方法,,,,而Get方法在表單時會在地址欄中顯示使用者名稱和密碼,而Post方法不會。
Servlet----------通過 HttpServlet 開發Servlet