checkname.java

一个简单的局域网网聊天程序 用Eclipse编写 数据库为SQL Server2

package com.xj.serv;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.xj.bean.DB;

public class checkName extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		HttpSession session = request.getSession();
		String u=request.getParameter("UserName");
		u=new String(u.getBytes("iso-8859-1"),"gb2312");
		u=u.toLowerCase();
		
		DB db = new DB();
		try {
			db.openConn();
			String s= db.checkUser(u);
			if(s.equals("")){
				session.setAttribute("empty", 0);
				//将当前用户明存起来,以便跳转回注册页后调用
				session.setAttribute("thisName", u);
			}else{
				session.setAttribute("empty", 1);
				
				session.setAttribute("thisName", "");
			}
		} catch (ClassNotFoundException e) {
			System.out.println(e.getMessage());
		} catch (SQLException e) {
			System.out.println(e.getMessage());
		}finally{
			try {
				db.closeRsAll();
				response.sendRedirect("reg.jsp");
			} catch (SQLException e) {
				System.out.println(e.getMessage());
			}
		}
	}

}