php自动加载autoload机制示例分享

php自动加载autoload机制示例分享

1，自定义函数

2，spl_autoload_register()

代码如下:
liuyuan@ebuinfo:/var/www/phpgcs/php_autoload$ ll ./*
-rw-rw-r-- 1 liuyuan liuyuan 800 Feb 19 11:39 ./func_autoload.php
-rw-rw-r-- 1 liuyuan liuyuan 906 Feb 19 11:28 ./spl_autoload.php

./include:
total 16
drwxrwxr-x 2 liuyuan liuyuan 4096 Feb 19 11:42 ./
drwxrwxr-x 3 liuyuan liuyuan 4096 Feb 19 11:43 ../
-rw-rw-r-- 1 liuyuan liuyuan 142 Feb 19 11:42 aClass.php
-rw-rw-r-- 1 liuyuan liuyuan 143 Feb 19 11:42 bClass.php

首先看自定义函数方式：

代码如下:
define('EOL', (PHP_SAPI == 'cli') ? PHP_EOL : '');
print_r(get_included_files());
echo EOL;
print get_include_path();
echo EOL;
//set_include_path(get_include_path().PATH_SEPARATOR.'/var/www/ly_php/php_spl/include/');
//set_include_path(dirname(__FILE__).'/include');
//set_include_path(dirname(__FILE__).'/include/');

function __autoload($className){
$filename = './include/'.$className.'.php';
//$filename = './include/'.$className.'.php';
//$filename = '/var/www/ly_php/php_spl/include/'.$className.'.php';
if(file_exists($filename)){
include_once $filename;
}else{
exit('no file');
}
}

$a = new aClass();
$b = new bClass();
print_r(get_included_files());
?>

运行结果如下：

代码如下:
liuyuan@ebuinfo:/var/www/phpgcs/php_autoload$ php func_autoload.php
Array
(
[0] => /var/www/phpgcs/php_autoload/func_autoload.php
)

.:/usr/share/php:/usr/share/pear
aClass is loaded
bClass is loaded
Array
(
[0] => /var/www/phpgcs/php_autoload/func_autoload.php
[1] => /var/www/phpgcs/php_autoload/include/aClass.php
[2] => /var/www/phpgcs/php_autoload/include/bClass.php
)

第二种方式：

代码如下:
class myLoader{
public static function autoload($className){
$filename = './include/'.$className.'.php';
if(file_exists($filename)){
include_once $filename;
}else{
exit('no file');
}
}
}

define('EOL', (PHP_SAPI == 'cli') ? PHP_EOL : '
');

spl_autoload_register(array('myLoader', 'autoload'));

/**
*__autoload 方法在 spl_autoload_register 后会失效，因为 autoload_func 函数指针已指向 spl_autoload 方法
* 可以通过下面的方法来把 _autoload 方法加入 autoload_functions list
*/
//spl_autoload_register( '__autoload' );


error_reporting(E_ALL^E_NOTICE^E_WARNING^E_ERROR);
error_reporting(E_NOTICE | E_WARNING );

$a = new aClass();
print_r(get_included_files());
echo EOL;
$b = new bClass();
echo EOL;
?>

运行结果如下：

代码如下:
liuyuan@ebuinfo:/var/www/phpgcs/php_autoload$ php spl_autoload.php
aClass is loaded
Array
(
[0] => /var/www/phpgcs/php_autoload/spl_autoload.php
[1] => /var/www/phpgcs/php_autoload/include/aClass.php
)

bClass is loaded