package impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import util.DB;
import dao.ILogin;
import entity.Operator;
import entity.Privilege;

public class LoginImpl implements ILogin {
	private PrivilegeImpl1 privilegeImpl = new PrivilegeImpl1();
	private RoleImpl roleImpl = new RoleImpl();
	private List<Privilege> list_privilege;
	private PreparedStatement pst;
	private Operator log_operator;
	private HttpSession session;
	private String checkResult;
	private Connection conn;
	private ResultSet rs;

	// 登录验证
	public String login(HttpServletRequest request, Operator operator) {
		session = request.getSession();
		checkResult = "success";
		log_operator = new Operator();
		try {
			conn = DB.getConn();
			pst = conn
					.prepareStatement("SELECT * FROM operator WHERE ope_name = ?");
			pst.setString(1, operator.getName());
			rs = pst.executeQuery();
			if (!rs.next()) {
				checkResult = "账户不存在，请重新输入！";
				session.setAttribute("isLogin", "false");
			} else {
				if (!operator.getPwd().equals(rs.getString(3))) {
					checkResult = "您输入的密码不正确，请重新输入！";
					session.setAttribute("isLogin", "false");
				} else {
					// 登录成功
					session.setAttribute("isLogin", "true");

					// 获得该用户的完整信息
					log_operator.setId(rs.getInt(1));
					log_operator.setName(rs.getString(2));
					log_operator.setPwd(rs.getString(3));
					log_operator.setRole(roleImpl.query("rol_id",
							rs.getString(4)).get(0));
					session.setAttribute("log_operator", log_operator);

					// 根据用户，获取对应的角色对应的权限
					list_privilege = privilegeImpl.query("rol_id", log_operator
							.getRole().getId()
							+ "");
					List<Privilege> list = new ArrayList<Privilege>();
					list.add(list_privilege.get(0));
					
					for (int i = 1; i < list_privilege.size(); i++) {
                          int y=0;
						for(int x=0;x<list.size();x++){
							
							if(!list.get(x).getMenu_name().equals(
									list_privilege.get(i).getMenu_name())){
								y++;
							}
						}
						if (y==list.size()) {
							list.add(list_privilege.get(i));

						}

					}
					session.setAttribute("list", list);
					session.setAttribute("list_privilege", list_privilege);
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			DB.close(conn, pst, rs);
		}
		return checkResult;
	}
}

链接数据库：

利用最基本的jdbc进行链接

package util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class DB {
	// 获取数据库连接
	public static Connection getConn() {
		Connection conn = null;
		String url = "jdbc:mysql://localhost:3306/jsp_studentmanager?characterEncoding=utf8";
		String name = "root";
		String pwd = "123456";
		try {
			Class.forName("com.mysql.jdbc.Driver");
			conn = DriverManager.getConnection(url, name, pwd);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return conn;
	}

	// 关闭对象 释放资源
	public static void close(Connection conn, PreparedStatement pst,
			ResultSet rs) {
		try {
			if (rs != null)
				rs.close();
			if (pst != null)
				pst.close();
			if (conn != null)
				conn.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

CREATE TABLE `NewTable` (
`stu_id`  int(11) NOT NULL AUTO_INCREMENT ,
`ope_id`  int(11) NULL DEFAULT NULL ,
`stu_no`  varchar(22) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,
`stu_name`  varchar(22) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,
`stu_sex`  enum('男','女') CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT '男' ,
`stu_birth`  date NULL DEFAULT NULL ,
`stu_pic`  varchar(22) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,
`cla_id`  int(11) NULL DEFAULT NULL ,
PRIMARY KEY (`stu_id`),
FOREIGN KEY (`cla_id`) REFERENCES `classes` (`cla_id`) ON DELETE CASCADE ON UPDATE CASCADE,
FOREIGN KEY (`ope_id`) REFERENCES `operator` (`ope_id`) ON DELETE CASCADE ON UPDATE CASCADE,
UNIQUE INDEX `uni_no` (`stu_no`) USING BTREE ,
UNIQUE INDEX `uni_ope` (`ope_id`) USING BTREE ,
INDEX `fk_stu_cla` (`cla_id`) USING BTREE ,
INDEX `fk_stu_ope` (`ope_id`) USING BTREE 
)
ENGINE=InnoDB
DEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ci
AUTO_INCREMENT=13
ROW_FORMAT=COMPACT
;

CREATE DEFINER=`root`@`localhost` TRIGGER `TG_3` AFTER DELETE ON `NewTable`
FOR EACH ROW BEGIN
DELETE FROM operator WHERE ope_id = old.ope_id;
END;

CREATE TABLE `NewTable` (
`sco_id`  int(11) NOT NULL AUTO_INCREMENT ,
`sco_daily`  float NULL DEFAULT 0 ,
`sco_exam`  float NULL DEFAULT 0 ,
`sco_count`  float NULL DEFAULT 0 ,
`stu_id`  int(11) NULL DEFAULT NULL ,
`sub_id`  int(11) NULL DEFAULT NULL ,
`cla2sub_id`  int(11) NOT NULL ,
`cla_id`  int(11) NOT NULL ,
PRIMARY KEY (`sco_id`),
FOREIGN KEY (`stu_id`) REFERENCES `student` (`stu_id`) ON DELETE CASCADE ON UPDATE CASCADE,
FOREIGN KEY (`sub_id`) REFERENCES `subject` (`sub_id`) ON DELETE CASCADE ON UPDATE CASCADE,
FOREIGN KEY (`cla2sub_id`) REFERENCES `cla2sub` (`cla2sub_id`) ON DELETE CASCADE ON UPDATE CASCADE,
FOREIGN KEY (`cla_id`) REFERENCES `classes` (`cla_id`) ON DELETE CASCADE ON UPDATE CASCADE,
UNIQUE INDEX `uni_stu_sub` (`stu_id`, `sub_id`, `cla2sub_id`) USING BTREE ,
INDEX `fk_sco_sub` (`sub_id`) USING BTREE ,
INDEX `fk_sco_stu` (`stu_id`) USING BTREE ,
INDEX `fk_sco_cla` (`cla2sub_id`) USING BTREE ,
INDEX `cla_id` (`cla_id`) USING BTREE 
)
ENGINE=InnoDB
DEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ci
AUTO_INCREMENT=33
ROW_FORMAT=COMPACT
;

CREATE TABLE `NewTable` (
`cla_id`  int(11) NOT NULL AUTO_INCREMENT ,
`cla_name`  varchar(22) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,
`maj_id`  int(11) NULL DEFAULT NULL ,
`cla_tec`  varchar(22) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,
PRIMARY KEY (`cla_id`),
FOREIGN KEY (`maj_id`) REFERENCES `major` (`maj_id`) ON DELETE CASCADE ON UPDATE CASCADE,
UNIQUE INDEX `uni_name` (`cla_name`) USING BTREE ,
INDEX `fk_cla_maj` (`maj_id`) USING BTREE 
)
ENGINE=InnoDB
DEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ci
AUTO_INCREMENT=8
ROW_FORMAT=COMPACT
;

CREATE DEFINER=`root`@`localhost` TRIGGER `TG_7` BEFORE DELETE ON `NewTable`
FOR EACH ROW BEGIN
DELETE FROM operator WHERE ope_id IN (SELECT ope_id FROM student WHERE cla_id = old.cla_id);
END;