getString() does not retrieve String bigger than 255 characters

Question

Data are in my excel sheet which contains several cols and rows. When I read the data using ResultSet string truncated 255 char.

Connection xlsConn = DriverManager.getConnection("jdbc:odbc:driver={Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb)};dbq=c:/production.xlsx");
ResultSet rs = xlsConn.createStatement().executeQuery("select * from [sheet1$]");       

while(rs.next()) 
    System.out.println( rs.getString("R1_Description").length() );

xlsConn.close();

Get 255 if the string has > 255 char.

Any help?