servlet的提交

servlet的提交和动态改变有点依赖xml

我们点击控件的时候改变了里面的变量，改变了xml，servlet发现变量变了，就会刷新页面

如果xml文档没有更新，浏览器采用缓存而不则行

<form action='"+requestURI+"'method='get'>
<input type='text' name='param' value='param string'>
<input type='submit' value='用get方式查询"+requestURI+"'></form>

action后面接要发到文档的url，（这个代码是发到自己那里，然后自己的文档更新了，页面也动态更新）

method是我们人为控制用什么方法(get/post

后面有些变量,比如 param...我们后面可以用String param=request.getParameter("param");来获得他

package servlet;

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 FirstServlet extends HttpServlet {

    /**
     * Constructor of the object.
     */
    public FirstServlet() {
        super();
    }

    /**
     * Destruction of the servlet. <br>
     */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /**
     * The doGet method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to get.
     * 
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.execute(request,response);
    }

    /**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     * 
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.execute(request,response);
    }

    /**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void execute(HttpServletRequest request,HttpServletResponse response)
        throws ServletException,IOException
    {
        this.log("则行doget方法");
        response.setCharacterEncoding("UTF-8");
        request.setCharacterEncoding("UTF-8");
        String requestURI=request.getRequestURI();
        String method=request.getMethod();
        String param=request.getParameter("param");
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">");
        out.println("<HTML>");
        out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
        out.println("  <BODY>");
        out.println(method+"方式访问该页面。取到的para参数是"+param+"<br/>");
        out.println("<form action='"+requestURI+"'method='get'><input type='text' name='param' value='param string'><input type='submit' value='用get方式查询"+requestURI+"'></form>");
        out.println("<form action='"+requestURI+"'method='post'><input type='text' name='param' value='param string'><input type='submit' value='用post方式查询"+requestURI+"'></form>");
        out.println("<script>document.write('本页面最后更新时间'+document.lastModified);</script>");
        out.println("  </BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();
    }
    public void init() throws ServletException {
        // Put your code here
    }

}

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