PHP实现货币换算的方法

本文实例讲述了PHP实现货币换算的方法。分享给大家供大家参考。

　　具体实现代码如下：

　　复制代码 代码如下:

　　<?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:///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";<
4000
br />

　　$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 = "{<Cubes*currency='(w*)'s*rate='([d.]*)'/>}is";

　　preg_match_all($pattern,$buffer,$xml_rates);

　　array_shift($xml_rates);

　　for($i=0;$i<count($xml_rates[0]);$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();

　　}

　　}

　　?>

　　上面的代码复制到一个新文件并将其保存为CurrencyConverter.php。当你需要转换包含类文件,称为“转换”功能。你需要输入自己的mysql数据库变量如登录详细信息。下面的例子将￡2.50英镑转换成美元(美元)。

　　复制代码 代码如下:

　　<?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');

　　?>