其实不要想得太难,简单实现:
    ...
    fileInputStream.writeLine("<students>");
    while(rs.hasNext()){
        fileInputStream.writeLine("<student>");
        fileInputStream.writeLine("<id>");
        fileInputStream.writeLine(rs.getInt("id"));
        fileInputStream.writeLine("</id>");        fileInputStream.writeLine("<name>");
        fileInputStream.writeLine(rs.getString("name"));
        fileInputStream.writeLine("</name>");        ....
        fileInputStream.writeLine("</student>");
    }
    fileInputStream.writeLine("</students>");