How can I convert an excel file to json by using javascript or java?

How can I convert an excel file to json by using javascript or java?

I have found this code below.However, I couldn't run it. I don't know which libraries I must use. I download json-simple and poi libraries but it doesn't work. Can anyone help me?

FileInputStream inp = new FileInputStream( file );
Workbook workbook = WorkbookFactory.create( inp );

// Get the first Sheet.
 Sheet sheet = workbook.getSheetAt( 0 );

    // Start constructing JSON.
    JSONObject json = new JSONObject();

    // Iterate through the rows.
    JSONArray rows = new JSONArray();
    for ( Iterator<Row> rowsIT = sheet.rowIterator(); rowsIT.hasNext(); )
    {
        Row row = rowsIT.next();
        JSONObject jRow = new JSONObject();

        // Iterate through the cells.
        JSONArray cells = new JSONArray();
        for ( Iterator<Cell> cellsIT = row.cellIterator(); cellsIT.hasNext(); )
        {
            Cell cell = cellsIT.next();
            cells.put( cell.getStringCellValue() );
        }
        jRow.put( "cell", cells );
        rows.put( jRow );
    }

    // Create the JSON.
    json.put( "rows", rows );

// Get the JSON text.
return json.toString();