checkuser.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 java.util.ArrayList;

import javax.servlet.ServletContext;
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;
import com.xj.bean.StringBufferClass;
import com.xj.bean.array;

public class checkUser 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 {
		
		response.setContentType("text/html;charset=gb2312");
		response.setCharacterEncoding("gb2312");
		request.setCharacterEncoding("gb2312");
		//session 和 appliction
		HttpSession session =request.getSession();
		ServletContext application = getServletContext();
		//得到用户名和密码
		String name=request.getParameter("name");
		String pass=request.getParameter("pass");
		name=name.toLowerCase();
		
		if(name.equals(""))
		{
			response.sendRedirect("index.jsp");
			session.removeAttribute("isuser");
			return;
			//request.getRequestDispatcher(arg0)
		}
		DB db = new DB();
		try {
			db.openConn();
			String s=db.getUser(name, pass);
			if(s.equals("")){
				session.setAttribute("isuser", "true");//设定session属性,判断用户输入是否正确
				response.sendRedirect("index.jsp");
				return;
			}
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
		ArrayList a = (ArrayList)application.getAttribute("userlist");
		
		array arr= new array(a);
		
		//存入一个session 用户名属性,以便聊天信息调用
		session.setAttribute("username", name);
		//判断用户名是否重复
		boolean x = arr.checkArr(name);

		if(x)
		{
			//存一个session属性,以便index.jsp页判断用户名是否重复
			session.setAttribute("bool",x );
			//将用户名放入arraylist 以便list.jsp调用
			a=arr.getArrayList(name);
			application.setAttribute("userlist", a);
			//打印欢迎信息
			StringBuffer sb=(StringBuffer)application.getAttribute("message");
			if(sb==null){
				sb=new StringBuffer("");
			}
			StringBufferClass sbc=new StringBufferClass(sb);
			String login="<br><font color=green>欢迎</font><font color=red>"+name+"</font><font color=green>来到聊天室</font><br><br>";
			sb=sbc.getSb(login);
			application.setAttribute("message", sb);
			response.sendRedirect("chatroom.jsp");	
		}
		else
		{
			response.sendRedirect("index.jsp");
			session.setAttribute("bool",x );
			
		}
	}
}