Servlet（6）Servlet三种开发方式之继承GenericServlet、HttpServlet及get和post提交表单方式的区别

电玩女神 2024-02-17 21:05 11阅读 0赞

实现Servlet接口方式：[http://blog.csdn.net/u013943420/article/details/70045713][http_blog.csdn.net_u013943420_article_details_70045713]

①使用继承GenericServlet方式开发Servlet（其他部署方式同上一篇一样）

package com.test;
    
    import javax.servlet.*;
    import javax.servlet.http.*;
    import java.io.*;
    
    public class MyFirstServlet extends GenericServlet
    {
        
    
        // 服务函数，我们的业务逻辑代码放在这里（每次都会被调用）
        public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
            response.setCharacterEncoding("utf-8");
            response.getWriter().println("hello GenericServlet!" + (new java.util.Date()).toLocaleString());
        }
    }

②使用继承HttpServlet方式开发Servlet(最常用的方式)

package com.test;
    
    import javax.servlet.*;
    import javax.servlet.http.*;
    import java.io.*;
    
    public class MyFirstServlet extends HttpServlet
    {
        public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            response.setCharacterEncoding("utf-8");
            response.getWriter().println("get hello HttpServlet!" + (new java.util.Date()).toLocaleString());
        }
    
        public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            response.setCharacterEncoding("utf-8");
            response.getWriter().println("post hello HttpServlet!" + (new java.util.Date()).toLocaleString());
        }
    }
    ------------------------login.html-----------------------
    <html>
        <body>
            <form action="/test/abc/jiaozl" method="post">
            u:<input type="text" name="username" />
            <input type="submit" value="login" />
        </body>
    
    </html>

③表单提交数据get请求和post请求的**区别**

- 安全性上，get<post
     - 提交内容上，get<post，get提交的数据不能大于2K，而post提交的数据理论上不受限制，实际中建议不大于64K
     - 请求响应速度上，get>post，get要求服务器立即处理请求，post可能形成一个队列请求

[http_blog.csdn.net_u013943420_article_details_70045713]: http://blog.csdn.net/u013943420/article/details/70045713