package com.wxpn.tutorial.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Collection;

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

import com.wxpn.tutorial.db.ConnectionPool;
import com.wxpn.tutorial.db.DB;

/**
 * Servlet implementation class for Servlet: LoginServlet
 */
public class LoginServlet extends javax.servlet.http.HttpServlet implements
		javax.servlet.Servlet {
	/*
	 * (non-Java-doc)
	 * 
	 * @see javax.servlet.http.HttpServlet#HttpServlet()
	 */
	public LoginServlet() {
		super();
	}

	/*
	 * (non-Java-doc)
	 * 
	 * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request,
	 *      HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
	}

	/*
	 * (non-Java-doc)
	 * 
	 * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request,
	 *      HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/html;charset=UTF-8");
		String result = "";

		// 獲取提交的用戶名：
		String strUserName = request.getParameter("txtUserName");
		// 獲取提交的密碼：
		String strPassword = request.getParameter("txtPassword");

		// 創(chuàng)建數(shù)據(jù)庫連接對象：
		ConnectionPool connPool = DB.getConnPool();
		Connection conn = connPool.getConnection();
		Statement stmt = null;
		ResultSet rs = null;

		try {
			// sql語句：
			String sql = "select * from userinfo where username='"
					+ strUserName + "' and userpwd='" + strPassword + "'";
			// 創(chuàng)建數(shù)據(jù)記錄集對象：
			stmt = conn.createStatement();
			// 執(zhí)行sql語句，返回一個記錄集到rs：
			rs = stmt.executeQuery(sql);
			// 如果記錄集為非空，表明有相匹配的用戶名和密碼，登錄成功：
			if (rs.next()) {
				// 登錄成功時,把strUserName設(shè)成session變量UserName
				request.getSession(true).setAttribute("userName", strUserName);
				
				response.sendRedirect("index.jsp");
			} else {
				// 否則（記錄集為空），表明失敗：
				request.setAttribute("error", "登錄失敗");
				try {
					request.getRequestDispatcher("/error.jsp").forward(request,
							response);
				} catch (Throwable t) {
					getServletContext().log(t.getMessage());
				}
			}
		} catch (SQLException sqlExc) {
			sqlExc.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			// 關(guān)閉連接，釋放數(shù)據(jù)庫資源：
			try {
				if (rs != null) {
					rs.close();
				}
				if (stmt != null) {
					stmt.close();
				}
				connPool.freeConnection(conn);
			} catch (SQLException sqlExc) {
				sqlExc.printStackTrace();
			}
		}
	}
}