通用的baseDao,连接数据库的方法之一

package y2jsp.students.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.List; import javax.naming.Context; import javax.naming.InitialContext; import javax.servlet.jsp.jstl.sql.Result; import javax.servlet.jsp.jstl.sql.ResultSupport; import javax.sql.DataSource; public class BaseDao { protected Connection conn; protected PreparedStatement ps; protected ResultSet rs; /** * 加载驱动建立数据库的连接 * @return 这个连接Connection */ /* public static synchronized Connection getConnection(){ String driverClassName=ReadProperties.getIntance().getProperty("driver"); String url=ReadProperties.getIntance().getProperty("url"); String user=ReadProperties.getIntance().getProperty("user"); String pass=ReadProperties.getIntance().getProperty("pass"); Connection conn=null; try{ Class.forName(driverClassName); conn=DriverManager.getConnection(url,user,pass); return conn; }catch(Exception ex){ ex.printStackTrace(); } return null; }*/ public Connection getConn(String jndiName){ try{ Context context=new InitialContext(); DataSource ds=(DataSource)context.lookup("java:comp/env/"+jndiName); return ds.getConnection(); }catch(Exception ex){ ex.printStackTrace(); return null; } } /** * 关闭连接释放资源 * @param conn * @param ps * @param rs */ public void closeAll(Connection conn,PreparedStatement ps,ResultSet rs){ try{ if(rs!=null){ rs.close(); rs=null; } if(ps!=null){ ps.close(); ps=null; } if(conn!=null){ conn.close(); conn=null; } }catch(Exception ex){ ex.printStackTrace(); } } /** * 数据的增删改操作 * @param sql * @param values * @return */ public int doExecuteSQL(String sql,List values){ try{ conn=this.getConn("jdbc/common"); ps=conn.prepareStatement(sql); this.setValues(ps, values); int s=ps.executeUpdate(); return s; }catch (Exception ex){ ex.printStackTrace(); return 0; }finally{ this.closeAll(conn, ps, null); } } public Result getAllDataInfo(String sql,List values){ try{ conn=this.getConn("jdbc/common"); ps=conn.prepareStatement(sql); this.setValues(ps, values); rs=ps.executeQuery(); return ResultSupport.toResult(rs); }catch(Exception ex){ ex.printStackTrace(); return null; }finally{ this.closeAll(conn, ps, rs); } } /** * 遍历传递过来的参数值 * @param ps * @param values */ public void setValues(PreparedStatement ps,List values){ if(values!=null){ for(int i=0;i<values.size();i++){ try{ ps.setObject(i+1,i); }catch (Exception ex){ ex.printStackTrace(); } } } } }