Change date format in Java?

Question

My date format ta yyyy-mm-dd and I want to change to dd-mm-yyyy

I’m pulling the data from an api, so I put it with the "-" example: 2017-12-31 because before it only came with 20171231 but I want to change to 31-12-2017

First I pull the API to my website:

function load() {
  var xhr = new XMLHttpRequest();

  xhr.open("GET", "API AQUI");

  xhr.addEventListener("load", function() {
      var resposta = xhr.responseText;
      console.log("ola1");
      var clientes = JSON.parse(resposta);
      console.log("ola2");
      console.log(clientes);

      for (var i =0; i < 1; i++){
          console.log("ola3");
         var clientes_1 = clientes.TRACKER[i];
         adicionaClienteNaTabelaEntregue(clientes_1);
         console.log("ola4");
     }

  });

  xhr.send();
      }
      window.onload = load;

Then I put it on my table

    function adicionaClienteNaTabelaEntregue(cliente) {
//    var pacienteTr = montaTr(cliente);
    var clienteTr = montaTr(cliente);
    var tabela = document.querySelector("#tabela-clientes");
    tabela.appendChild(clienteTr);
}

function montaTr(cliente) {
    var clienteTr = document.createElement("tr");
    clienteTr.classList.add("cliente");

      clienteTr.appendChild(montaTd(cliente.DTAENT, "info-entconfirmada"));
      clienteTr.appendChild(montaTd(cliente.DTAMONORC, ".info-montprevista"));
      clienteTr.appendChild(montaTd(cliente.DTAMON, ".info-montconfirmada"));
      clienteTr.appendChild(montaTd(cliente.FILORC, "info-loja"));

    return clienteTr;
}

function montaTd(dado, classe) {
    var td = document.createElement("td");
    td.classList.add(classe);
    td.textContent = dado;

    return td;
}

And the API data comes like this:

DTAMON:"2017-07-24"
DTAMONORC:"2017-07-12"
DTAPREENT:"2017-07-14"

Answer 1

Perhaps the fastest and perhaps not very safe way (if the format is always in this pattern, can be used smoothly), but, functional would be:

var _str = '2016-03-01';
_new = _str.split('-').reverse().join('-');
console.log(_new);

the split will break this text into 3 parts of a array, the command re-verse will change the order where the first will be the last the second the last and so on and Join reassemble the date in the desired format, joining all positions with the informed tab.

---

In your current code create a function as follows:

function formatDate(str)
{
    return str.split('-').reverse().join('-');
}

and in your code call:

function montaTr(cliente) 
{
    var clienteTr = document.createElement("tr");
    clienteTr.classList.add("cliente");

    clienteTr.appendChild(montaTd(formatDate(cliente.DTAENT), "info-entconfirmada"));
    clienteTr.appendChild(montaTd(formatDate(cliente.DTAMONORC), ".info-montprevista"));
    clienteTr.appendChild(montaTd(formatDate(cliente.DTAMON), ".info-montconfirmada"));
    clienteTr.appendChild(montaTd(cliente.FILORC, "info-loja"));

    return clienteTr;
}

References

• String.prototype.split()
• Array.prototype.Reverse()
• Array.prototype.Join()