Download File PDF in Angular from Spring MVC

Question

I have this situation. In AngularJs:

    var graphHtml = $(".element10")[0];

    $http({
        method: 'POST', 
        url: '/export/pdf', 
        data: "html=" + graphHtml.outerHTML,
        headers: {'Content-Type': 'application/x-www-form-urlencoded'}
    }).success(function(data, status, headers, config) {
        var hiddenElement = document.createElement('a');
        hiddenElement.href = 'data:application/pdf;' + encodeURI(data);
        hiddenElement.target = '_blank';
        hiddenElement.download = 'myFile.pdf';
        hiddenElement.click();
    }).error(function(data, status, headers, config) {
    });

In Spring:

    FileInputStream in = new FileInputStream(new File(myGeneratedFile));
    OutputStream out = response.getOutputStream();
    final int bufferSize = 8192;

    byte[] buffer = new byte[bufferSize];
    int read;

    while ((read = in.read(buffer, 0, bufferSize)) != -1) {
        out.write(buffer, 0, read);
    }

In Javascript I receive the binary data of file PDF and save the content in success section. When I open the file occurs a problem with the format. The issue is the function encodeURI? How can write correctly binary data? Thanks in advance