我正在将一个用javascript构建的文件保存到本地互联网下载目录中。
这项工作：
javascript
var filename = "mysave.txt"
var contents = "xyz";
document.location = "htmlsave.php?filename=" + filename + "&contents=" + contents;
htmlsave.php：
if(!isset($_GET)) {
exit(0);
}
$filename = $_GET['filename'];
$contents = $_GET['contents'];
header("Pragma: public"); // required
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private", false); // required for certain browsers
header("Content-Type: application/octet-stream");
header("Content-Disposition: attachment; filename='"" . $filename . "'";" );
header("Content-Transfer-Encoding: binary");
header("Content-Length: " . strlen($contents));
header("Connection: close");
echo $contents;
这不是：
javascript:
var i;
var filename = "mysave.txt"
var contents = "";
for(i=0, contents = "";i<10000;i++){
contents += "x";
}
document.location = "htmlsave.php?filename=" + filename + "&contents=" + contents;
由于url的2K限制，这显然不起作用。
错误为：
Request-URI Too Long
The requested URL's length exceeds the capacity limit for this server.
显然，您需要使用POST，但是如何使用POST呢？如何对POST数据执行"document.location="位？您无法执行ajax POST（见下文），我已经尝试过了，但它不起作用。
失败的POST方法：
javascript:
var filename = "mysave.txt"
var contents = "";
for(i=0, contents = "";i<10000;i++){
contents += "x";
}
dataARR = {
filename: filename,
contents: contents
};
var dataJSON = JSON.stringify(dataARR);
$.ajax({
type: "POST", // This for array
url: "htmlsave.php",
async: true,
cache: false,
crossDomain: false, // This needs to be true for other people
data: { myJson: dataJSON },
success: function (data) {
},
error: function (XMLHttpRequest, textStatus, errorThrown) {
}
});
htmlsave.php
if(!isset($_POST) || !isset($_POST['myJson'])) {
exit(0);
}
$dataTotal = json_decode($_POST['myJson'], true);
$filename = $dataTotal['filename'];
$contents = $dataTotal['contents'];
header("Pragma: public"); // required
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private", false); // required for certain browsers
header("Content-Type: application/octet-stream");
header("Content-Disposition: attachment; filename='"" . $filename . "'";" );
header("Content-Transfer-Encoding: binary");
header("Content-Length: " . strlen($contents));
header("Connection: close");
echo $contents;
那么，如何保存大于2K的文件呢？
php不需要创建，提示用户保存在javascript创建的文件。您可以使用包含文件数据的Blob中download属性设置为filename、href设置为objectURL的<a>元素来启动提示用户保存文件。
如果要使用php，可以使用php://input、file_get_contents()、echo、POST ed Blob或File对象。
var i;
var filename = "mysave.txt"
var contents = "";
for(i=0, contents = "";i<10000;i++){
contents += "x";
}
var data = new Blob([contents], {type:"text/plain"});
var file = URL.createObjectURL(data);
var a = document.createElement("a");
a.download = filename;
a.href = file;
a.click();使用file_ge_contents()、php://input
javascript
var i;
var filename = "mysave.txt"
var contents = "";
for(i=0, contents = "";i<10000;i++){
contents += "x";
}
var data = new Blob([contents], {type:"text/plain"});
var request = new XMLHttpRequest();
request.open("POST", "/path/to/server");
request.setRequestHeader("x-file-name", filename);
request.reponseType = "blob";
request.onload = function() {
console.log(this.response); // `echo`ed file
};
request.send(data);
php
echo file_get_contents("php://input");
另请参阅从通过ajax发送的dataURI生成带有php的png文件；尽管注意request.setRequestHeader("x-file-name", filename);本应包含在php 的$tmpFilename = $_SERVER["HTTP_X_FILE_NAME"];的应答的javascript部分