php的文件上传
文件上传
php的文件上传放在了$_FILES数组里，单文件和多文件上传的区别在于$_FILES['userfile']['name']是否为数组，
不熟悉的可以读一下官方文档 单文件上传、 多文件上传
阿里云oss web直传实践
这里采用的是服务端签名后上传，没有使用回调。
阿里云提供了一个php和前端的示例，不过有点坑人，前端采用的是plupload插件，这种demo应该使用原生js更合适啊，毕竟上传的js插件各不相同。
使用jquery的ajax上传时，始终上传失败，于是用fiddler抓包demo，才知道了上传给oss的详细参数格式。
吐槽完毕，下面才是正式上菜。
- 服务端生成policy，这里使用php
下面的代码是从官方demo修改而来，可以通过Facade模式增加静态方法，方便调用。
注意dir目录不能使用"/"开始。下面的签名算法来自阿里云的demo。
<?php
class OssPolicy
{
private $oss_bucket ;
private $oss_host;
private $oss_appid;
private $oss_appsecret;
private $oss_expire ;//过期时间
/**
* OssPolicy constructor.
* @param $bucket 阿里云oss的bucket
* @param $host 对应bucket的host
* @param $appId app_id
* @param $appSecret app_secret
* @param int $expire 过期时间
*/
public function __construct($bucket,$host,$appId,$appSecret,$expire=900) {
$this->oss_expire = $expire;
$this->oss_bucket = $bucket;
$this->oss_host = $host;
$this->oss_appid = $appId;
$this->oss_appsecret = $appSecret;
}
private function gmt_iso8601($time) {
$dtStr = date("c", $time); //格式为2016-12-27T09:10:11+08:00
$mydatetime = new DateTime($dtStr);
$expiration = $mydatetime->format(DateTime::ISO8601); //格式为2016-12-27T09:12:32+0800
$pos = strpos($expiration, '+');
$expiration = substr($expiration, 0, $pos);//格式为2016-12-27T09:12:32
return $expiration."Z";
}
/**
* @function getPolicy 获取policy
* @author
* @version 1.0
* @date
* @param $dir 上传目录
* @param $maxSize 最大文件大小 单位M
* @param int $expireTime 过期时间
* @return $array policy
*/
public function getPolicy($dir,$maxSize=100,$expireTime=null){
$expireTime = isset($expireTime) ? $expireTime : $this->oss_expire;
$end = time() + $expireTime;
$expiration = $this->gmt_iso8601($end);
$conditions = [];
$conditions[] = array(0=>'content-length-range', 1=>0, 2=>1024*1024*$maxSize); // 最大文件大小.用户可以自己设置 100M
$start = array(0=>'starts-with', 1=>'$key', 2=>$dir); //表示用户上传的数据,必须是以$dir开始, 不然上传会失败,这一步不是必须项,只是为了安全起见,防止用户通过policy上传到别人的目录
$conditions[] = $start;
$arr = array('expiration'=>$expiration,'conditions'=>$conditions);
$policy = json_encode($arr);
$base64_policy = base64_encode($policy);
$string_to_sign = $base64_policy;
$signature = base64_encode(hash_hmac('sha1', $string_to_sign, $this->oss_appsecret, true));
$response = array();
$response['accessid'] = $this->oss_appid;
$response['host'] = $this->oss_host;
$response['policy'] = $base64_policy;
$response['signature'] = $signature;
$response['expire'] = $end;
$response['bucket'] = $this->oss_bucket;
$response['dir'] = $dir; //这个参数是设置用户上传指定的前缀
return $response;
}
}
- 前端
过程 想后端请求policy，上传到阿里云，成功后通知后端
不要问我代码为啥这么乱，我不生产代码，我只是代码的搬运工(从阿里云demo里搬出来，稍加修改)
在用表单提交时，注册一下提交处理的函数，取出文件，然后OssUpload()即可。
oss_accessid = ''
oss_accessoss_key = ''
oss_host = ''
oss_policyBase64 = ''
oss_signature = ''
oss_callbackbody = ''
oss_filename = ''
oss_key = ''
oss_expire = 0
g_object_name = ''
g_object_name_type = 'local_name'
OSS_FILE_NAME_TYPE_LOCAL = "local_name"
OSS_FILE_NAME_TYPE_RANDOM = "random_name"
oss_now = oss_timestamp = Date.parse(new Date()) / 1000;
//向服务端请求policy
function send_request() {
}
//生成签名
function get_oss_signature() {
//可以判断当前oss_expire是否超过了当前时间,如果超过了当前时间,就重新取一下.3s 做为缓冲
oss_now = oss_timestamp = Date.parse(new Date()) / 1000;
if (oss_expire < oss_now + 3) {
body = send_request()
var obj = eval("(" + body + ")");
oss_host = obj['host']
oss_policyBase64 = obj['policy']
oss_accessid = obj['accessid']
oss_signature = obj['signature']
oss_expire = parseInt(obj['expire'])
oss_callbackbody = obj['callback']
oss_key = obj['dir']
}
}
//随机字符串
function random_string(len) {
len = len || 32;
var chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678';
var maxPos = chars.length;
var str = '';
for (i = 0; i < len; i++) {
str += chars.charAt(Math.floor(Math.random() * maxPos));
}
return str;
}
//获取文件名后缀
function get_suffix(filename) {
pos = filename.lastIndexOf('.')
suffix = ''
if (pos != -1) {
suffix = filename.substring(pos)
}
return suffix;
}
//根据文件名类型 临时文件还是原始文件名，返回文件名
function calculate_object_name(filename) {
if (g_object_name_type == 'local_name') {
g_object_name = oss_key + "${filename}"
}
else if (g_object_name_type == 'random_name') {
suffix = get_suffix(filename)
g_object_name = oss_key + random_string(10) + suffix
}
return ''
}
//把policy填充到Formdata里
function set_upload_param(file) {
get_oss_signature()
if (file) {
calculate_object_name(file.name);
var res = {
'key': g_object_name,
'policy': oss_policyBase64,
'OSSAccessKeyId': oss_accessid,
'success_action_status': '200', //让服务端返回200,不然，默认会返回204
// 'callback': oss_callbackbody,
'signature': oss_signature,
};
var form_data = new FormData();
for ( var key in res ) {
form_data.append(key, res[key]);
}
form_data.append("file",file);
return res;
}
return false;
}
//上传到阿里云 callBack 是用来在上传成功后通知服务端
function OssUpload( file,fileNameType,callBack) {
g_object_name_type = fileNameType;
var form_data = set_upload_param(file.name);
if(!form_data){
alert("form_data error")
return
}
var fileFullName = oss_host+form_data.get("key");
$.ajax({
url: oss_host,
data: form_data,
processData: false,
cache: false,
async: false,
type:'POST',
contentType: false,//这个就是了
success: function (data, textStatus, request) {
//textStatus === "success" 表示成功
if(typeof callBack === "function") {
callBack(fileFullName,form_data.get("policy"),textStatus);
}
},
error : function(responseStr) {
if(typeof callBack === "function") {
callBack(fileFullName,form_data.get("policy"),responseStr.responseText);
}
}
});
}