使用PHP的Guzzle HTTP库代替AWS S3 API lite实现对S3的访问。

1. 首先安装Guzzle HTTP库：

composer require guzzlehttp/guzzle

2. 接下来使用以下代码示例替换原有的AWS S3 API lite代码：

use GuzzleHttp\Client;
use GuzzleHttp\Exception\RequestException;

class S3Client
{
    private $client;

    public function __construct($base_uri, $access_key, $secret_key)
    {
        $this->client = new Client([
            'base_uri' => $base_uri,
            'auth' => [$access_key, $secret_key],
        ]);
    }

    public function getObject($bucket, $key)
    {
        try {
            $response = $this->client->get($bucket . '/' . $key);
            return $response->getBody();
        } catch (RequestException $e) {
            return null;
        }
    }

    public function putObject($bucket, $key, $body)
    {
        try {
            $this->client->put($bucket . '/' . $key, ['body' => $body]);
            return true;
        } catch (RequestException $e) {
            return false;
        }
    }

    public function deleteObject($bucket, $key)
    {
        try {
            $this->client->delete($bucket . '/' . $key);
            return true;
        } catch (RequestException $e) {
            return false;
        }
    }
}

3. 使用示例：

$s3Client = new S3Client('https://s3.amazonaws.com', 'ACCESS_KEY', 'SECRET_KEY');

// 上传对象
$s3Client->putObject('BUCKET_NAME', 'OBJECT_KEY', 'OBJECT_CONTENTS');

// 获取对象内容
$contents = $s3Client->getObject('BUCKET_NAME', 'OBJECT_KEY');

// 删除对象
$s3Client->deleteObject('BUCKET_NAME', 'OBJECT_KEY');