}
catch (java.lang.ClassNotFoundException e) {System.err.println
("dbclass():"+e.getMessage());}
try
{
conn=DriverManager.getConnection(conn_str,username,password);
}
catch (SQLException ex )
{ System.err.println("dbclass():"+ex.getMessage ());}
}
//——取得数据库连接——
public Connection getConn ()
{
return conn ;
}
//——数据库查询——public ResultSet query(String sql)
{
try
{
stmt=conn.createStatement ();
rs=stmt.executeQuery(sql );}
catch (SQLException ex ) {System.err.println("query():"+ex.getMessage
());}
return rs ;
}
//——————————-数据库修改————————-
public void update(String sql)
{
try
{
stmt=conn.createStatement ();
stmt.executeUpdate(sql );}
catch (SQLException ex ) {System.err.println("update ():"+ex.getMessage
());}
}
//——————————关闭数据源——————-
public void closestmt ()
{
try{stmt.close();}
catch (SQLException ex ) {System.err.println("closestmt():"+ex.getMessage
());}
}
//——————————关闭链接————————-
public void closeconn ()
{
try{conn.close();}
catch (SQLException ex ) {System.err.println("closeconn()"+ex.getMessage