var links = getAllDownloadLinks();

var link = links[0];
var filePath = getPath(link.getDownloadPath());
var downloadFolder = getPath(link.getPackage().getDownloadFolder()).getAbsolutePath();

alert(filePath);
alert(filePath.getAbsolutePath());//Not returning string
alert(downloadFolder);
alert(downloadFolder.getAbsolutePath());//Not returning String
writeFile(JD_HOME + "/testfile.txt",filePath + "\r\n", true);
writeFile(JD_HOME + "/testfile.txt",filePath.getAbsolutePathn() + "\r\n", true);//Not returning String