When I wanted to write a word into Excel file that is containing some of these characters, version 2.5.1 was not displaying it properly.
I updated the version of POI and the display problem resolved.
HSSFCell.ENCODING_UTF_16 includes required character support.
HSSFRow newRow = sheet.createRow((short)1); newRow.createCell((short) 0).setCellValue("Başvuru Numarası"); HSSFCell cell0 = row.getCell((short) 0); cell0.setCellType(HSSFCell.CELL_TYPE_STRING); cell0.setEncoding(HSSFCell.ENCODING_UTF_16);
Required dependency for pom.xml file is :
org.apache.poi poi 3.1-FINAL