处理从ajax pos下载的文件

Answer 1

不要这么快放弃，因为这可以（在现代浏览器中）使用FileAPI的一部分来完成：

var xhr = new XMLHttpRequest();
xhr.open('POST', url, true);
xhr.responseType = 'arraybuffer';
xhr.onload = function () {
    if (this.status === 200) {
        var filename = "";
        var disposition = xhr.getResponseHeader('Content-Disposition');
        if (disposition && disposition.indexOf('attachment') !== -1) {
            var filenameRegex = /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/;
            var matches = filenameRegex.exec(disposition);
            if (matches != null && matches[1]) filename = matches[1].replace(/['"]/g, '');
        }
        var type = xhr.getResponseHeader('Content-Type');

        var blob;
        if (typeof File === 'function') {
            try {
                blob = new File([this.response], filename, { type: type });
            } catch (e) { /* Edge */ }
        }
        if (typeof blob === 'undefined') {
            blob = new Blob([this.response], { type: type });
        }

        if (typeof window.navigator.msSaveBlob !== 'undefined') {
            // IE workaround for "HTML7007: One or more blob URLs were revoked by closing the blob for which they were created. These URLs will no longer resolve as the data backing the URL has been freed."
            window.navigator.msSaveBlob(blob, filename);
        } else {
            var URL = window.URL || window.webkitURL;
            var downloadUrl = URL.createObjectURL(blob);

            if (filename) {
                // use HTML5 a[download] attribute to specify filename
                var a = document.createElement("a");
                // safari doesn't support this yet
                if (typeof a.download === 'undefined') {
                    window.location = downloadUrl;
                } else {
                    a.href = downloadUrl;
                    a.download = filename;
                    document.body.appendChild(a);
                    a.click();
                }
            } else {
                window.location = downloadUrl;
            }

            setTimeout(function () { URL.revokeObjectURL(downloadUrl); }, 100); // cleanup
        }
    }
};
xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
xhr.send($.param(params));

这是使用jQuery.ajax的旧版本。当响应转换为某个字符集的字符串时，它可能会损坏二进制数据。

$.ajax({
    type: "POST",
    url: url,
    data: params,
    success: function(response, status, xhr) {
        // check for a filename
        var filename = "";
        var disposition = xhr.getResponseHeader('Content-Disposition');
        if (disposition && disposition.indexOf('attachment') !== -1) {
            var filenameRegex = /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/;
            var matches = filenameRegex.exec(disposition);
            if (matches != null && matches[1]) filename = matches[1].replace(/['"]/g, '');
        }

        var type = xhr.getResponseHeader('Content-Type');
        var blob = new Blob([response], { type: type });

        if (typeof window.navigator.msSaveBlob !== 'undefined') {
            // IE workaround for "HTML7007: One or more blob URLs were revoked by closing the blob for which they were created. These URLs will no longer resolve as the data backing the URL has been freed."
            window.navigator.msSaveBlob(blob, filename);
        } else {
            var URL = window.URL || window.webkitURL;
            var downloadUrl = URL.createObjectURL(blob);

            if (filename) {
                // use HTML5 a[download] attribute to specify filename
                var a = document.createElement("a");
                // safari doesn't support this yet
                if (typeof a.download === 'undefined') {
                    window.location = downloadUrl;
                } else {
                    a.href = downloadUrl;
                    a.download = filename;
                    document.body.appendChild(a);
                    a.click();
                }
            } else {
                window.location = downloadUrl;
            }

            setTimeout(function () { URL.revokeObjectURL(downloadUrl); }, 100); // cleanup
        }
    }
});

Answer 2

创建一个表单，使用POST方法，提交表单-不需要iframe。当服务器页面响应请求时，为文件的mime类型编写一个响应头，它将显示一个下载对话框-我已经多次这样做了。

您需要应用程序/下载的内容类型-只需搜索如何为您正在使用的任何语言提供下载。

Answer 3

我也面临同样的问题并成功地解决了它。我的用例是这样的。

“将JSON数据发送到服务器并接收excel文件。 该excel文件由服务器创建，并作为对客户端的响应返回。在浏览器中将该响应下载为具有自定义名称的文件“

$("#my-button").on("click", function(){

// Data to post
data = {
    ids: [1, 2, 3, 4, 5]
};

// Use XMLHttpRequest instead of Jquery $ajax
xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
    var a;
    if (xhttp.readyState === 4 && xhttp.status === 200) {
        // Trick for making downloadable link
        a = document.createElement('a');
        a.href = window.URL.createObjectURL(xhttp.response);
        // Give filename you wish to download
        a.download = "test-file.xls";
        a.style.display = 'none';
        document.body.appendChild(a);
        a.click();
    }
};
// Post data to URL which handles post request
xhttp.open("POST", excelDownloadUrl);
xhttp.setRequestHeader("Content-Type", "application/json");
// You should set responseType as blob for binary responses
xhttp.responseType = 'blob';
xhttp.send(JSON.stringify(data));
});

上面的代码片段正在执行以下操作

• 使用XMLHttpRequest将数组作为JSON发布到服务器。
• 以blob（二进制）形式获取内容后，我们将创建一个可下载的URL，并将其附加到不可见的“a”链接，然后单击它。

在这里，我们需要在服务器端仔细设置一些东西。我在Python Django HttpResponse中设置了几个头。如果使用其他编程语言，则需要相应地设置它们。

# In python django code
response = HttpResponse(file_content, content_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")

因为我在这里下载了xls（excel），所以我将contentType调整为1以上。你需要根据你的文件类型设置它。您可以使用此技术下载任何类型的文件。