java.lang.StringIndexOutOfBoundsException reading excel special character

I am using a google excel to export as excel file(xls). and if i tried to read using my java, i encountered java.lang.StringIndexOutOfBoundsException error.

this error only happens when I keyed in a special character in the cell, like below

amount ($)

however, if i keyed it without spacing..like below. - no error... amount($)

help..me...

error message realExceptionjava.lang.StringIndexOutOfBoundsException: String index out of range: 1

my code

switch (cell.getCellType()) {
                case Cell.CELL_TYPE_STRING:
                    //excelMaker=cell.getStringCellValue().trim(); =tried-fail
                    //excelMaker=cell.getRichStringCellValue().toString().trim(); =tried-fail
                    excelMaker=cell.getRichStringCellValue().getString(); //tried fail
                    System.out.println("excelFormMaker"+excelFormMaker);
                    if(excelMaker.trim().equalsIgnoreCase("na")){
                        excelFormMaker="na"; 
                    }
                    excelContent.add(excelMaker);
                    break;

i am using -- poi 3.11 lib version

++solve problem.

it caused due to my other method( change to camel case) inside the method , i replace all spacing to "" and change a special character to "" as well. however the consequence of replacing was wrong.