var formData = new FormData();
var xhr = new XMLHttpRequest();
xhr.open('POST', 'ServletMessage', true);
xhr.send(formData);
and I write this value in the database, the problem is that the page refreshes before writing to bd, and the value does not change on the screen. How can I wait for the servlet to write to the database, and then the page refresh?
You need to set a function to handle the event XMLHttpRequest.onreadystatechange . This event fires whenever the order status changes. To do something when the request is finished (state XMLHttpRequest.DONE ), we do something like this:
var nome = document.getElementById('nome').value;
var postData = 'nome=' + encodeURIComponent(nome);
var xhr = new XMLHttpRequest();
xhr.open('POST', 'ServletMessage', true);
xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhr.onreadystatechange = function () {
if(xhr.readyState === XMLHttpRequest.DONE) {
if (xhr.status === 200)
console.log('Pedido concluído com sucesso, atualize a página');
else
console.log('Erro');
}
};
xhr.send(postData);