json时间格式转成js时间

function p(s) {
return s < 10 ? '0' + s : s;
}
function jsonTimeFormat(str) {
//var str = "/Date(1283457528340)/";
var matches = str.match(/([0-9]+)/);
var d = parseInt(matches[0]);
var obj = new Date(d);
var year = obj.getFullYear();
var month = obj.getMonth() + 1;
var day = obj.getDate();

var mytime = year + "-" + p(month) + "-" + p(day) + " " + p(obj.getHours()) + ":" + p(obj.getMinutes())+":"+p(obj.getSeconds());
return mytime;
}

str ="/Date(1283457528340)/";