import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import java.sql.SQLException;import java.sql.Statement;public class OperateDB ...{ public static ResultSet queryDB(String sql)throws ClassNotFoundException...{ Connection con=null; Statement stmt=null; ResultSet rs=null; //StringBuffer sb=new StringBuffer(); try...{ //Class.forName("com.mysql.jdbc.Driver"); con=OperateDB.getConnection(con); //con=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/menagerie","root","333"); stmt=con.createStatement(); rs=stmt.executeQuery(sql); }catch(Exception e)...{ e.printStackTrace(); } return rs; } public static int updateDB(String sql)throws ClassNotFoundException...{ Statement sm=null; Connection con=null; int affectRows=0; try...{ con=OperateDB.getConnection(con); //con=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/menagerie","root","333"); sm=con.createStatement(); affectRows=sm.executeUpdate(sql); }catch(Exception e)...{ e.printStackTrace(); System.out.println("error updateDB!"); affectRows=Statement.EXECUTE_FAILED; }finally...{ closeStatement(sm); } return affectRows; } public static void closeStatement(Statement sm)...{ if(sm!=null)...{ try...{ sm.close(); }catch(SQLException e)...{ e.printStackTrace(); } } } /**//*public static void showResultSet(ResultSet rs){ if(rs==null){ return; } try{ ResultSetMetaData md=rs.getMetaData(); int columnCount = md.getColumnCount(); if(!rs.isBeforeFirst()){ rs.beforeFirst(); } while(rs.next()){ for(int i=0;i<columnCount;i++){ System.out.print(rs.getObject(i)+" "); } System.out.print(rs.getObject(columnCount)+" "); rs.beforeFirst(); } }catch(SQLException e){ e.printStackTrace(); } }*/ public static Connection getConnection(Connection con) throws ClassNotFoundException...{ try...{ Class.forName("com.mysql.jdbc.Driver"); if(con==null)...{ con=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/menagerie","root","333"); } }catch(SQLException e)...{ e.printStackTrace(); } return con; } public static void closeConnection(Connection con)...{ if(con!=null)...{ try...{ con.close(); }catch(SQLException e)...{ e.printStackTrace(); } } } public static void main(String []args) throws ClassNotFoundException...{ String sql=""; ResultSet rs=null; Connection con=null; Statement sm=null; int inte=0; sql="select * from pet;"; String updatesql="update pet set sex=null where birth='1997-12-09'"; try...{ rs=OperateDB.queryDB(sql); //OperateDB.showResultSet(rs); while(rs.next())...{ System.out.println(rs.getObject("name")); } inte=OperateDB.updateDB(updatesql); System.out.println("updateDB= "+inte); }catch(Exception e)...{ e.printStackTrace(); } finally...{ try...{ rs.close(); }catch(SQLException e)...{ e.printStackTrace(); } closeStatement(sm); closeConnection(con); } }}