1.将Symfony2类加载器复制到Symfony 1.4沙箱项目的供应商目录：

SF_ROOT_DIR/lib/vendor/Symfony2/src/Symfony/Component/ClassLoader/UniversalClassLoader.PHP

SF_ROOT_DIR/lib/vendor/Symfony2/src/Symfony/Component/ClassLoader/ApcUniversalClassLoader.PHP

2.修改SF_ROOT_DIR / config / ProjectConfiguration.class.PHP文件,如下所示：

require_once dirname(__FILE__) . '/../lib/vendor/symfony/lib/autoload/sfCoreAutoload.class.PHP';
require_once dirname(__FILE__) . '/../lib/autoload/sfClassLoader.class.PHP';
sfCoreAutoload::register();

class ProjectConfiguration extends sfProjectConfiguration {

    public function setup() {
        $this->namespacesClassLoader();
        $this->enablePlugins('sfDoctrinePlugin');
    }

    public function namespacesClassLoader() {
       if (extension_loaded('apc')) {
           $loader = new ApcUniversalClassLoader('S2A');
       } else {
           $loader = new UniversalClassLoader();
       }
       $loader->registerNamespaces(array(
          'Pohon' => __DIR__ . '/../lib/vendor/Pohon/src'));
       $loader->register();
    }

}

3.注册所需的命名空间：

例如.我想加载类：

Pohon\Tools\String\Utils\Slugify.

文件名必须是：

SF_ROOT_DIR/lib/vendor/Pohon/src/Pohon/Tools/String/Utils/Slugify.PHP

和注册的命名空间如下：

Pohon => SF_ROOT_DIR/lib/vendor/Pohon/src