@bruce

yeah, i'm setting the content type to "application/json". here is all my code when an event click on an element is triggered. 

function menuclicked() {
    var request = new XMLHttpRequest();
    request.open("GET", 'jd/getcontent'); // Specify URL to fetch
    request.setRequestHeader("Content-Type",
"application/json");
    request.onreadystatechange = function () {
        
        if (request.readyState === 4 && request.status === 200) {
           alert((JSON.parse(request.responseText)));
        }
        else if (request.readyState === 4 && request.status !== 200)
            alert('error');
    };

    request.send(JSON.stringify({ name: this.dataset.name }));
}

Still i'm having this same problem !

thanks for your reply~!