php自动加载autoload机制示例分享

1，自定义函数

2，spl_autoload_register()

复制代码 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：

复制代码 代码如下:
<?php
    define("EOL", (PHP_SAPI == "cli") ? PHP_EOL : "</ br>");
    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：

复制代码 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：

复制代码 代码如下:
<?php
    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 : "<br />");    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：

复制代码 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