初学servlet，蛋疼了

下面是servlet代码
package com.hello;
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;/**
 * Servlet implementation class FirstServlet
 */
public class FirstServlet extends HttpServlet {
private static final long serialVersionUID = 1L;    /**
     * Default constructor. 
     */
    public FirstServlet() {
        // TODO Auto-generated constructor stub
    } /**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 */
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.log("执行doGet方法...");
this.execute(request,response);
} /**
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 */
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.log("执行doPost方法...");
this.execute(request,response);
} @Override
protected long getLastModified(HttpServletRequest req) {
this.log("执行getLastModified方法...");
return super.getLastModified(req);
}
private void execute(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{
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("以"+method+"方式访问该页面。取到的param参数为"+param+"<br/>");
out.println("<form action = '"+requestURI+"'method = 'get'>" +
"<input type = 'text' name = 'param' value = 'param string'>" +
"<input type = 'submit' value = '以GET方式查询页面"+requestURI+"'>" +
"</form>");
out.println("<form action = '"+requestURI+"'method = 'post'>" +
"<input type = 'text' name = 'param' value = 'param string'>" +
"<input type = 'submit' value = '以POST方式查询页面"+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();
}
}