用Firefox擴展檢查URL是否存在與Javascript

Question

我想檢查給定的URL是否存在使用帶有Firefox擴展的Javascript。

Answer 1

我想你想嘗試加載URL - 使用XMLHttpRequest爲：

var request = new XMLHttpRequest(); 
request.open("GET", url); 
request.onload = function() 
{ 
    if ((request.status >= 200 && request.status < 300) || request.status == 304) 
     alert("Exists!"); 
    else 
     alert("HTTP response isn't success, URL doesn't exist or is currently unavailable"); 
}; 
request.onerror = function() 
{ 
    alert("Loading URL errored out, server doesn't exist or is currently unavailable"); 
}; 
request.send(null);