java poi excel导入模板设置下拉框

import org.apache.poi.hssf.usermodel.DVConstraint;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFDataValidation;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.util.CellRangeAddressList;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;


// 初始一个workbook
HSSFWorkbook workbook = new  HSSFWorkbook();
// 创建一个sheet
HSSFSheet sheet=  workbook.createSheet();
// 创建行
HSSFRow row= sheet.createRow(0);
// 创建列
HSSFCell cell= row.createCell(index++);
// 准备下拉列表数据
List<BasicDBObject> options = (List<BasicDBObject>) bo.get("options");
String[] optionArr = new String[options.size()];
for (int i = 0; i < options.size(); i++) {
    optionArr[i] = options.get(i).getString("value");
}
// 设置第一列的1-10000行为下拉列表
CellRangeAddressList regions = new CellRangeAddressList(0, 10000, 0, 0);
// 创建下拉列表数据
DVConstraint constraint = DVConstraint.createExplicitListConstraint(optionArr);
// 绑定
HSSFDataValidation dataValidation = new HSSFDataValidation(regions, constraint);
sheet.addValidationData(dataValidation);