IO

<script type="text/javascript">

function readFile() {
    // un-sandbox file system to access shared folder
    blackberry.io.sandbox = false;

    window.requestFileSystem  = window.requestFileSystem || window.webkitRequestFileSystem;

    window.requestFileSystem(window.TEMPORARY, 1024 * 1024,
        function (fs) {
             // in order to access the shared folder,
             // config.xml must declare the "access_shared" permission
             // reference file by absolute path since file system is un-sandboxed
             fs.root.getFile(blackberry.io.sharedFolder + '/Documents/log.txt', {create: true},
                 function (fileEntry) {
                     fileEntry.file(function (file) {
                         var reader = new FileReader();

                         reader.onloadend = function (e) {
                             var txtArea = document.createElement('textarea');
                             txtArea.value = this.result;
                             document.body.appendChild(txtArea);
                         };

                         reader.readAsText(file);
                    }, errorHandler);
                 }, errorHandler);
        });
}

function errorHandler(e) {
    var msg = '';

    switch (e.code) {
    case FileError.QUOTA_EXCEEDED_ERR:
        msg = 'QUOTA_EXCEEDED_ERR';
        break;
    case FileError.NOT_FOUND_ERR:
        msg = 'NOT_FOUND_ERR';
        break;
    case FileError.SECURITY_ERR:
         msg = 'SECURITY_ERR';
         break;
    case FileError.INVALID_MODIFICATION_ERR:
         msg = 'INVALID_MODIFICATION_ERR';
         break;
    case FileError.INVALID_STATE_ERR:
         msg = 'INVALID_STATE_ERR';
         break;
    default:
         msg = 'Unknown Error';
        break;
    };

    console.log('Error: ' + msg);
}
</script>