mvc Java 三层结构编程

package news; import java.sql.*; /** * */ /** * @author asus * */ public class conn { String sDBDriver="org.git.mm.mysql.Driver"; String sConnStr="jdbc:mysql://localhost/test"; Connection connect=null; ResultSet rs=null; public conn(){ try{ Class.forName(sDBDriver); } catch(java.lang.ClassNotFoundException e){ System.err.println(e.getMessage()); } } public ResultSet executeQuery(String sql){ try{ connect=DriverManager.getConnection(sConnStr,"root","zcy"); Statement stmt=connect.createStatement(); rs=stmt.executeQuery(sql); } catch(SQLException ex){ System.err.println(ex.getMessage()); } return rs; } public int executeUpdate(String sql){ int result=0; try{ connect=DriverManager.getConnection(sConnStr,"root","123"); Statement stmt=connect.createStatement(); result=stmt.executeUpdate(sql);//执行数据操作语句 } catch(SQLException ex){ System.out.println(ex.getMessage()); } return result; } public void close(){ if(connect!=null) { try{ connect.close(); connect=null; }catch(SQLException ex){ System.err.println(ex.getMessage()); } } } }