loginservlet.java

通过JSP技术实现商品房产的查询与购买

package ch14.Servlet;

import java.io.IOException;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import ch14.JavaBean.User;
import ch14.JavaBean.DB_User;


/**
 * 
 * @author ly
 * 
 * 用户登陆
 */

public class LoginServlet extends javax.servlet.http.HttpServlet 
                            implements javax.servlet.Servlet {
	//构造函数
	public LoginServlet() {
		super();
	}
	
	//服务器端的验证、提交处理
	protected void doPost(HttpServletRequest request,HttpServletResponse response) 
	                 throws ServletException, IOException {
		response.setContentType("text/html;charset=GB2312");
		
		// 获取提交的用户名：
		String UserName = request.getParameter("logname");
		// 获取提交的密码：
		String Password = request.getParameter("logpwd");
		String EnPwd =Password;
		String Type=request.getParameter("type");

		//核对用户名和密码，决定是否通过登陆验证
		try
		{
			DB_User dbuser = new DB_User();
			User user = dbuser.get(UserName, EnPwd);
			if (user != null) 
			{
				if(user.getType()==Integer.parseInt(Type))
				{
					// 登录成功时,把strUserName设成session变量UserName
					request.getSession(true).setAttribute("username", UserName);
					try {
						if(Type.equals("0"))
							request.getRequestDispatcher("combo_query.jsp").forward(request,response);
						else
							request.getRequestDispatcher("company.jsp").forward(request,response);
						} 
					catch (Throwable t) {
						getServletContext().log(t.getMessage());
					}
				}
				else{
					request.setAttribute("error", "类型选择不正确,请重试！");
					try {
						request.getRequestDispatcher("Login.jsp").forward(request, response);
					} 
					catch (Throwable t) {
						getServletContext().log(t.getMessage());
					}
				}
					
			} else {
				// 否则（记录集为空），表明失败：
				request.setAttribute("error", "用户名与密码不匹配,登录失败,请重试！");
				try {
					request.getRequestDispatcher("Login.jsp").forward(request, response);
				} 
				catch (Throwable t) {
					getServletContext().log(t.getMessage());
				}
			}
		}
		catch(SQLException ex)
		{
			ex.printStackTrace();
		}
	}
}