FIle copyTo not working in cordova

问题

In my cordova(v 3.3) application i used copyTo for copy files from one directory to another directory in sdcard. Some time it is working fine some time it is not working. Here is the source i used to copy files from one dierctory to another.

window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function gotFS(fileSystem) {
         var root = fileSystem.root.fullPath;
         console.log(skiTemplateFileName);
         alert(root);

         var fails = function(err) { alert(err.code);}
            window.resolveLocalFileSystemURI(root+"/"+TEMPLATE_DIRECTORY+""+TemplateFileName, function(file) {
               window.resolveLocalFileSystemURI(root+"/"+PDF_DIRECTORY, function(destination) {
                         file.copyTo(destination,randomFileName);
                         alert("File Download Successfully");
               },fails)
            },fails);
     }, function fail(e){

     });

when copy files first time only shows the file download success. For next time it shows only root alert

Note : This issue occurs in samsung tab 4(v4.4.2) devices working well in nexus 7.

Please guide to solve this issue.

来源：https://stackoverflow.com/questions/27455884/file-copyto-not-working-in-cordova