checkusernameservlet.java

网上订餐系统

package com.newer.ajax.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;

import com.newer.ajax.dao.UserDao;
import com.newer.bean.User;

public class CheckUserNameServlet extends HttpServlet {

	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		try {
			Thread.currentThread().sleep(3000);
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		response.setContentType("text/html;charset=UTF-8");
		PrintWriter out = response.getWriter();
		
		// 取得请求参数值
		String userName = new String(request.getParameter("userName").getBytes(
				"ISO-8859-1"), "UTF-8");
		
		// 调用服务器业务方法
		UserDao userDao = new UserDao();
		User user = userDao.getUserByName(userName);

		if(user==null){
			out.print("<font color='red'>用户名可以使用</font>");
		}else{
			out.println("用户名已经存在");
		}
	}
	
	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		doGet(request,response);
	}
}