Android สอบถามหน่อยครับ สร้างไฟล์ เวลาเทสในเครื่องมันมีไฟล์พอไปรันในมือถือจริงๆไม่มี

try {
        	
            File data = new File(("/data/myapp"),"Report:"+Day+":"+Shift+".csv");
            BufferedWriter writer = new BufferedWriter(new FileWriter(data));
            int z = 0;
            int countb = Integer.valueOf(arrDataAllt2[0][10]);
          
            writer.append("Time"+",");
    		writer.append("Day"+",");
    		writer.append("Name"+",");
    		writer.append("NumberEx"+",");
    		writer.append("Shift"+",");
    		writer.append("TimeIN"+",");
    		writer.append("TimeOUT"+",");
    		writer.append("Truck"+",");
    		writer.append("Latitude"+",");
    		writer.append("Longitude");
    		writer.newLine();
    		
        	for(z = 0;z<=countb-1;z++)
      		{
        		writer.append(arrDataAllt2[z][0]+",");
        		writer.append(arrDataAllt2[z][1]+",");
        		writer.append(arrDataAllt2[z][2]+",");
        		writer.append(arrDataAllt2[z][3]+",");
        		writer.append(arrDataAllt2[z][4]+",");
        		writer.append(arrDataAllt2[z][5]+",");
        		writer.append(arrDataAllt2[z][6]+",");
        		writer.append(arrDataAllt2[z][7]+",");
        		writer.append(arrDataAllt2[z][8]+",");
        		writer.append(arrDataAllt2[z][9]);
        		writer.newLine();
      		}
         
            writer.flush();
            writer.close();
        } catch (IOException ex) {
            System.out.println("File could not be created");
        }