validateservlet.java

该主要使关于AJAX的一些相关内容

package com.briup.web;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import java.util.Vector;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ValidateServlet extends HttpServlet {
	private List<String> users
			=new Vector<String>();
	public void init(){
		users.add("briup");
		users.add("peter");
		users.add("jason");
		users.add("kevin");
	}
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String username
		=request.getParameter("username");
		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
		PrintWriter pw=response.getWriter();	
		if(users.contains(username)){
			pw.println(
			"<font size=\"3\" color=\"red\">");
			pw.println("用户名已经被占用!");
			pw.println("</font>");
		}else{
			pw.println(
			"<font size=\"3\" color=\"blue\">");
			pw.println("可以使用此用户名!");
			pw.println("</font>");
		}
		pw.flush();
		pw.close();
	}
}