POI set the data format of the column (valid)

Post code explanation directly , Try it yourself ！

// Format text 
        HSSFCellStyle textStyleNum = workbook.createCellStyle();
        textStyleNum.setDataFormat(HSSFDataFormat.getBuiltinFormat("@"));

// Date format 
        HSSFDataFormat format= workbook.createDataFormat();
        textStyleNum.setDataFormat(format.getFormat("yyyy year m month d Japan "));

        // Keep two decimal places 
        textStyleNum.setDataFormat(HSSFDataFormat.getBuiltinFormat("0.00"));
// The first parameter refers to which column is set , The second parameter refers to HSSFCellStyle  object 
  sheet.setDefaultColumnStyle(2, textStyleNum);