POI excel cell wrap

Mode one ： Folding does not work
String str1 = "aaabbb"; // Object to wrap
// do other
HSSFCellStyle style = workbook.createCellStyle(); // Create cell styles
style.setWrapText(true);  // Cell contents wrap

 
Mode two ： Line break
String str1 = "aaa\r\nbbb"; // Object to wrap --"\r\n" Must exist in the object to wrap , otherwise style.setWrapText(true); It doesn't work