login.java

基于javaSwing的图书馆信息管理系统 使用oracle数据库连接

package com.lib.db.oper;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

import com.lib.DBConnection;
import com.lib.db.Borr;

//登录操作
public class Login {
	// 用flag来标识 登录状态
	// flag == n 未登录
	// flag == a 管理员
	// flag == b 学生或老师(借阅者)
	public static char FLAG = 'n';
	// 登录ID记录(保存到Borr值对象中)
	public static Borr BORR = null;
	

	public static Connection con = DBConnection.getConnection();

	/**
	 * 通过对lib_admin表和lib_borrower表中 查询 管理员或用户 的名字,得到其密码,用于登录时密码确认
	 * 
	 * @param username
	 * @return
	 */
	public static String getPwd(String username) {
		String tmppwd = null;		
		Statement stmt = null;
		
		String str = "Select pwd from lib_admin where admin_id = '"+username+"'";

		String str1 = "Select * from lib_borr where login = '"+username+"'";
		try {
			stmt = con.createStatement();
			ResultSet rs = stmt.executeQuery(str);
			if (rs.next()) {
				tmppwd = rs.getString("pwd");
				FLAG = 'A';
			} else {
				rs.close();
				System.out.println("检查是否为用户登录");
				rs = stmt.executeQuery(str1);
				if (rs.next()) {
					System.out.println("用户登录");					
					
					
					String card_id = rs.getString("card_id");
					String borrower_id = rs.getString("borrower_id");
					String borrower = rs.getString("borrower");
					//String login = rs.getString("login");
					String login = username;
					String email = rs.getString("email");
					String phone = rs.getString("phone");
					String isStudent = rs.getString("isStudent");
					int borrow_num = rs.getInt("borrow_num");
					
					tmppwd = rs.getString("pwd");
					FLAG = 'B';
					
					BORR = new Borr(card_id, borrower_id, borrower, login, tmppwd, email, phone, isStudent, borrow_num);
				}
			}
		}catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				stmt.close();
				// con.close();
			} catch (Exception ee) {
				ee.printStackTrace();
			}
		}
		return tmppwd;

	}
}