PHP实现货币换算的方法

具体实现代码如下：

代码如下:

<&＃63;php
/*
* File: CurrencyConverter.php
* Author: Simon Jarvis
* Copyright: 2005 Simon Jarvis
* Date: 10/12/05
* Link: http://www.white-hat-web-design.co.uk/articles/php-currency-conversion.php
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details:
* http://www.gnu.org/licenses/gpl.html
*
*/
class CurrencyConverter {
var $xml_file = "www.ecb.int/stats/eurofxref/eurofxref-daily.xml";
var $mysql_host, $mysql_user, $mysql_pass, $mysql_db, $mysql_table;
var $exchange_rates = array();
//Load Currency Rates
function CurrencyConverter($host,$user,$pass,$db,$tb) {
$this->mysql_host = $host;
$this->mysql_user = $user;
$this->mysql_pass = $pass;
$this->mysql_db = $db;
$this->mysql_table = $tb;
$this->checkLastUpdated();
$cOnn= mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);
$rs = mysql_select_db($this->mysql_db,$conn);
$sql = "SELECT * FROM ".$this->mysql_table;
$rs = mysql_query($sql,$conn);
while($row = mysql_fetch_array($rs)) {
$this->exchange_rates[$row['currency']] = $row['rate'];
}
}
/* Perform the actual conversion, defaults to £1.00 GBP to USD */
function convert($amount=1,$from="GBP",$to="USD",$decimals=2) {
return(number_format(($amount/$this->exchange_rates[$from])*$this->exchange_rates[$to],$decimals));
}
/* Check to see how long since the data was last updated */
function checkLastUpdated() {
$cOnn= mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);
$rs = mysql_select_db($this->mysql_db,$conn);
$sql = "SHOW TABLE STATUS FROM ".$this->mysql_db." LIKE '".$this->mysql_table."'";
$rs = mysql_query($sql,$conn);
if(mysql_num_rows($rs) == 0 ) {
$this->createTable();
} else {
$row = mysql_fetch_array($rs);
if(time() > (strtotime($row["Update_time"])+(12*60*60)) ) {
$this->downloadExchangeRates();
}
}
}
/* Download xml file, extract exchange rates and store values in database */
function downloadExchangeRates() {
$currency_domain = substr($this->xml_file,0,strpos($this->xml_file,"/"));
$currency_file = substr($this->xml_file,strpos($this->xml_file,"/"));
$fp = @fsockopen($currency_domain, 80, $errno, $errstr, 10);
if($fp) {
$out = "GET ".$currency_file." HTTP/1.1rn";
$out .= "Host: ".$currency_domain."rn";
$out .= "User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8) Gecko/20051111 Firefox/1.5rn";
$out .= "Connection: Closernrn";
fwrite($fp, $out);
while (!feof($fp)) {
$buffer .= fgets($fp, 128);
}
fclose($fp);
$pattern = "{}is";
preg_match_all($pattern,$buffer,$xml_rates);
array_shift($xml_rates);
for($i=0;$i $exchange_rate[$xml_rates[0][$i]] = $xml_rates[1][$i];
}
$cOnn= mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);
$rs = mysql_select_db($this->mysql_db,$conn);
foreach($exchange_rate as $currency=>$rate) {
if((is_numeric($rate)) && ($rate != 0)) {
$sql = "SELECT * FROM ".$this->mysql_table." WHERE currency='".$currency."'";
$rs = mysql_query($sql,$conn) or die(mysql_error());
if(mysql_num_rows($rs) > 0) {
$sql = "UPDATE ".$this->mysql_table." SET rate=".$rate." WHERE currency='".$currency."'";
} else {
$sql = "INSERT INTO ".$this->mysql_table." VALUES('".$currency."',".$rate.")";
}
$rs = mysql_query($sql,$conn) or die(mysql_error());
}
}
}
}
/* Create the currency exchange table */
function createTable() {
$cOnn= mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);
$rs = mysql_select_db($this->mysql_db,$conn);
$sql = "CREATE TABLE ".$this->mysql_table." ( currency char(3) NOT NULL default '', rate float NOT NULL default '0', PRIMARY KEY(currency) ) ENGINE=MyISAM";
$rs = mysql_query($sql,$conn) or die(mysql_error());
$sql = "INSERT INTO ".$this->mysql_table." VALUES('EUR',1)";
$rs = mysql_query($sql,$conn) or die(mysql_error());
$this->downloadExchangeRates();
}
}
&＃63;>

代码如下:

<&＃63;php
include('CurrencyConverter.php');
$x = new CurrencyConverter('your_host','your_username','your_password','your_database_name','your_table_name');
echo $x->convert(2.50,'GBP','USD');
&＃63;>

希望本文所述对大家的php程序设计有所帮助。