studentmanager.java

自己用java编写的基于B/S的在线考试系统

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

public class StudentManager {
	public boolean isLogin(Student student) {
		boolean flag = false;
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		String sql = "select * from student where id=" + student.getId()
				+ " and name='" + student.getName() + "'";
		try {
			conn = DBConnection.getConnection();
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			if (rs.next()) {
				flag = true;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}
//管理员登陆
	public boolean isLoginByAdmin(Admin admin) {
		boolean flag = false;
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		String sql = "select * from admin where name='" + admin.getName()
				+ "' and password='" + admin.getPassword() + "'";
		try {
			conn = DBConnection.getConnection();
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			if (rs.next()) {
				flag = true;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}
   //模糊查询
	public List queryByLike(String cond) {
		List list = new ArrayList();
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		String sql = "select * from student where name like '%" + cond + "%'";
		try {
			conn = DBConnection.getConnection();
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			while (rs.next()) {
				Student student = new Student();
				student.setId(rs.getInt("id"));
				student.setName(rs.getString("name"));
				student.setSex(rs.getString("sex"));
				student.setScore(rs.getInt("score"));
				student.setJointime(rs.getDate("jointime"));
				list.add(student);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return list;
	}

	public boolean insertStudent(Student student) {
		boolean flag = false;
		Connection conn = null;
		PreparedStatement pstmt = null;
		String sql = "insert into student(name,sex) values(?,?)";
		try {
			conn = DBConnection.getConnection();
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, student.getName());
			pstmt.setString(2, student.getSex());
			int tmp = pstmt.executeUpdate();
			if(tmp==0){
				flag = false;
			}else{
				flag = true;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}

	public boolean insertAdmin(Admin admin) {
		boolean flag = false;
		Connection conn = null;
		PreparedStatement pstmt = null;
		String sql = "insert into admin values(?,?,?)";
		try {
			conn = DBConnection.getConnection();
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, admin.getName());
			pstmt.setString(2, admin.getPassword());
			pstmt.setString(3, admin.getRight());
			int tmp = pstmt.executeUpdate();
			if(tmp==0){
				flag = false;
			}else{
				flag = true;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}

	public boolean delStudent(int id) {
		boolean flag = false;
		Connection conn = null;
		PreparedStatement pstmt = null;
		String sql = "delete from student where id=?";
		try {
			conn = DBConnection.getConnection();
			pstmt = conn.prepareStatement(sql);
			pstmt.setInt(1, id);
			int tmp = pstmt.executeUpdate();
			if(tmp==0){
				flag = false;
			}else{
				flag = true;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}

	public boolean delAdmin(String name) {
		boolean flag = false;
		Connection conn = null;
		PreparedStatement pstmt = null;
		String sql = "delete from admin where name=?";
		try {
			conn = DBConnection.getConnection();
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, name);
			pstmt.executeUpdate();
			flag = true;
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}

	public boolean updateStudent(Student student) {
		boolean flag = false;
		Connection conn = null;
		PreparedStatement pstmt = null;
		String sql = "update student set name=?,sex =?,flag =? where id =?";
		try {
			conn = DBConnection.getConnection();
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, student.getName());
			pstmt.setString(2, student.getSex());
			pstmt.setString(3, student.getFlag());
			pstmt.setInt(4, student.getId());
			pstmt.executeUpdate();
			flag = true;
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}

	public boolean updateStudentScore(Student student) {
		boolean flag = false;
		Connection conn = null;
		PreparedStatement pstmt = null;
		String sql = "update student set score=? ,jointime = now() where id =?";
		try {
			conn = DBConnection.getConnection();
			pstmt = conn.prepareStatement(sql);
			pstmt.setInt(1, student.getScore());
			pstmt.setInt(2, student.getId());
			int tmp = pstmt.executeUpdate();
			if(tmp<0){
				flag = false;
			}else{
				flag = true;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}

	public boolean updateAdmin(Admin admin) {
		boolean flag = false;
		Connection conn = null;
		PreparedStatement pstmt = null;
		String sql = "update admin set password = ? where name=?";
		try {
			conn = DBConnection.getConnection();
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, admin.getPassword());
			pstmt.setString(2, admin.getName());
			pstmt.executeUpdate();
			flag = true;
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return flag;
	}

	public List queryAdminByAll() {
		List list = new ArrayList();
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		String sql = "select * from admin";
		try {
			conn = DBConnection.getConnection();
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			while (rs.next()) {
				Admin admin = new Admin();
				admin.setId(rs.getInt("id"));
				admin.setName(rs.getString("name"));
				admin.setPassword(rs.getString("password"));
				admin.setRight(rs.getString("right"));
				list.add(admin);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return list;
	}

	public Student queryStudent(int id) {
		Student student = new Student();
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		String sql = "select * from student where id="+id;
		try {
			conn = DBConnection.getConnection();
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			if (rs.next()) {
				student.setId(id);
				student.setName(rs.getString("name"));
				student.setSex(rs.getString("sex"));
				student.setScore(rs.getInt("score"));
				student.setJointime(rs.getDate("jointime"));
			}else{
				student = null;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return student;
	}

	public List queryStudentByAll() {
		List list = new ArrayList();
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		String sql = "select * from student";
		try {
			conn = DBConnection.getConnection();
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			while (rs.next()) {
				Student student = new Student();
				student.setId(rs.getInt("id"));
				student.setName(rs.getString("name"));
				student.setSex(rs.getString("sex"));
				student.setScore(rs.getInt("score"));
				student.setJointime(rs.getDate("jointime"));
				list.add(student);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DBConnection.closeConnection(conn);
		}
		return list;
	}
}