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  • Servlet----------通过 HttpServlet 开发Servlet

    通过继承HttpServlet抽象类,功能更强大。

    通过HttpServlet方法开发Servlet需要重写doGet和doPost方法。这是目前用的最多的一种方法。

    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,设计者对post提交和get提交分别处理  
    13     //<form action="提交给?" method="post|get">,默认是get提交  
    14     //其实,doGet和doPost最终也去调用了Servlet接口中的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>

     

    由结果可知,默认调用的是doGet方法,,,,而Get方法在表单时会在地址栏中显示用户名和密码,而Post方法不会。

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  • 原文地址:https://www.cnblogs.com/limn/p/7206109.html
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