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
} }