Answers for "how to check if a mp3 file exists in android"

php check if file exists

if (!file_exists('http://mysite.com/images/thumbnail_1286954822.jpg')) {   
$filefound = '0';                         
}

check if file exists javascript

function executeIfFileExist(src, callback) {
    var xhr = new XMLHttpRequest()
    xhr.onreadystatechange = function() {
        if (this.readyState === this.DONE) {
            callback()
        }
    }
    xhr.open('HEAD', src)
}