模仿地铁购票系统+数据库

package cn.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class BaseDao { private static final String DRIVERCLASS="com.microsoft.sqlserver.jdbc.SQLServerDriver"; private static final String URL="jdbc:sqlserver://localhost:1433;databaseName=subway"; private static final String USERNAME="sa"; private static final String PASSWORD="123"; private Connection conn; private PreparedStatement ps; private ResultSet rs; public Connection getConnection() { try { Class.forName(DRIVERCLASS); conn=DriverManager.getConnection(URL,USERNAME,PASSWORD); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return conn; } public int executeSQL(String sql,Object[] args) { int rowNum=0; getConnection(); try { ps=conn.prepareStatement(sql); } catch (SQLException e) { e.printStackTrace(); } if(args!=null&&args.length>0) { int index=1; for (Object object : args) { try { ps.setObject(index++, object); } catch (SQLException e) { e.printStackTrace(); } } } try { rowNum=ps.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); } finally { this.closeAll(); } return rowNum; } public ResultSet execQuery(String sql,Object[] args) { getConnection(); try { ps=conn.prepareStatement(sql); } catch (SQLException e) { e.printStackTrace(); } if(args!=null&&args.length>0) { int index=1; for (Object object : args) { try { ps.setObject(index++, object); } catch (SQLException e) { e.printStackTrace(); } } } try { rs=ps.executeQuery(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return rs; } public void closeAll() { if(rs!=null) { try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if(ps!=null) { try { ps.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if(conn!=null) { try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public ResultSet execQuery(String sql, Object args) { getConnection(); try { ps=conn.prepareStatement(sql); } catch (SQLException e) { e.printStackTrace(); } if(args!=null) { try { ps.setObject(1, args); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { rs=ps.executeQuery(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return rs; } }