자바 엑셀 여러 시트 내 보 내기 (sheet 여러 개 추가)

//    excel  
		 WritableWorkbook wwb = null;    
	        try {    
	            //     Workbook                 (Workbook)      
	            wwb = Workbook.createWorkbook(new File(fileName));
	        } catch (IOException e) {    
	        	   log.error(e);
	        }    
		long totle = service.getTotle(searchParameters);//      ，    ，   excel      
		// 65536     
		float res=Float.parseFloat(String.valueOf(totle));
		float mus=65536;
		float avg=res/mus;
		Map cols = (Map) request.getSession().getAttribute("columnsMap"); //      
		for (int i = 0; i < avg+1; i++) {
			searchParameters.setEvent_id(String.valueOf(i*mus)); //      
			searchParameters.setTotalLimit(String.valueOf((i+1)*mus));//      
			List result = service.getEvents(searchParameters); //      
			
			  if(wwb!=null){    
		            //               
		            //Workbook createSheet       ，          ，                   
		            WritableSheet ws = wwb.createSheet("  "+(i+1), i);  
		            String colss = ((String) cols.get("cols")).substring("selected"
		    				.length() + 1);
		    		String[] columns = colss.split(","); //      （    ）
		    		String[] colNames = ((String) cols.get("colNames")).split(",");
		            for (int j = 0; j < columns.length; j++) {
		            	jxl.write.WritableFont wfc = new jxl.write.WritableFont(WritableFont.ARIAL,10,WritableFont.NO_BOLD,false,jxl.format.UnderlineStyle.NO_UNDERLINE,jxl.format.Colour.BLACK); 
		            	jxl.write.WritableCellFormat wcfFC = new jxl.write.WritableCellFormat(wfc); 
		            	wcfFC.setBackground(Colour.GRAY_25);
		            	Label label = new Label(j, 0,colNames[j],wcfFC);
		            	ws.setColumnView(j, 20); //    
		            	ws.addCell(label);  //    
					}
		            String str="";
		            //             
		            for(int m=0;m