checkuser.java

网上购物系统

package example.common.servlet;

import java.sql.SQLException;

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

import com.shsafe.common.database.DatabaseConnection;
import com.shsafe.common.database.DatabaseConnectionManager;

import example.regeist.RegeistDAO;


public class CheckUser extends HttpServlet {
	
	/**
	 * serialVersionUID
	 */
	private static final long serialVersionUID = 3232701569690691744L;
	
	private String msgStr = "";
	
	DatabaseConnection connection = null;
	
	RegeistDAO dao = null;

	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException{
		try {
			connection = DatabaseConnectionManager.getMyConnection();
			dao = new RegeistDAO(connection);
		} catch (SQLException e) {
			//throw e ;
		}
		String oprate = request.getParameter("oprate").trim();
		String userName = request.getParameter("userId");
		try {
			if (oprate.equals("chkUser")) {
				response.setContentType("text/html;charset=GB2312");
				boolean bTmp = dao.findUserByUserId(userName); // 找查数据库中有无该用户名
				if (bTmp)
					msgStr = "此用户名已经存在";
				else
					msgStr = "";
				}
				response.getWriter().write(msgStr);
		} catch (Exception ex) {
			
		}
	}

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