package pethospitalsystem;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.sql.*;

//用來處理用戶注冊頁面的Servlet.

public class UserRegisterServlet extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=GBK";

    //Initialize global variables
    public void init() throws ServletException {
    }

    //Process the HTTP Get request
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        response.setContentType(CONTENT_TYPE);
        //得到由超鏈接傳過來的username的值.
        String uname=request.getParameter("uname");

        Connection con=null;
        SQLBean sqlb=new SQLBean();
        //判斷用戶輸入的用戶名是否可用.
        try {
            if (sqlb.getCon() != null) {
                con = sqlb.getCon();
                Statement stmt = con.createStatement();
                String strSql="select * from UserInfo where UserName='"+uname+"'";
                ResultSet rs=stmt.executeQuery(strSql);
                if (rs.next()) {
                    response.sendRedirect("ExistUsername.jsp");
                } else {
                    response.sendRedirect("InexistenceUsername.jsp");
                }
            }
        } catch (Exception ex) {
            System.out.println(ex.getMessage());
        }
    }

    //Process the HTTP Post request
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        doGet(request, response);
    }

    //Clean up resources
    public void destroy() {
    }
}