在servlet上上传canvas base64图像

Question

I am uploading HTML5 canvas base64 image over servlet using following JavaScript code

function saveDataURL(a) {
    var postData = "canvasData="+a;
    var ajax = new XMLHttpRequest();
    ajax.open("POST",'uploadPhoto.cgi',true);
    ajax.send(postData);    }

but on server when i see request.getAttribute("canvasData") its give me null value even when i debug java code request shows me null. What code should i write on Java, i have tried decoding Base64 request but as request itself contains nothing any help on code,tutorial much appreciated

Answer 1

Apart from the url encoding set the content type to application/x-www-form-urlencoded

function saveDataURL(a) {
    var postData = "canvasData="+encodeURIComponent(a);
    var ajax = new XMLHttpRequest();
    ajax.open("POST",'uploadPhoto.cgi',true);
    ajax.setRequestHeader("Content-type","application/x-www-form-urlencoded");
    ajax.send(postData);    
}