参考了这位大佬的代码:https://blog.csdn.net/qq_42747210/article/details/113063645
主要原因是:excel本身每个单元格限制了255个字符,下拉框总字符超过255就无法正常打开
因为我有多列需要下拉框,所有用Map来装数据,key为需要下拉框的列,value为该列下拉框的值;我只是设置了序号为1到50的行需要下拉框;
import java.util.Map; import org.apache.poi.ss.usermodel.DataValidation; import org.apache.poi.ss.usermodel.DataValidationConstraint; import org.apache.poi.ss.usermodel.DataValidationHelper; import org.apache.poi.ss.usermodel.Name; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.ss.util.CellRangeAddressList; import com.alibaba.excel.write.handler.SheetWriteHandler; import com.alibaba.excel.write.metadata.holder.WriteSheetHolder; import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder; public class CustomSheetWriteHandler implements SheetWriteHandler { private Map<Integer, String[]> map; private int index; public CustomSheetWriteHandler(Map<Integer, String[]> map) { this.map = map; this.index = 0; } @Override public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) { // TODO Auto-generated method stub } @Override public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) { DataValidationHelper helper = writeSheetHolder.getSheet().getDataValidationHelper(); // k 为存在下拉数据集的单元格下表 v为下拉数据集 map.forEach((k, v) -> { // 创建sheet,突破下拉框255的限制 // 获取一个workbook Workbook workbook = writeWorkbookHolder.getWorkbook(); // 定义sheet的名称 String sheetName = "sheet" + k; // 1.创建一个隐藏的sheet 名称为 proviceSheet Sheet proviceSheet = workbook.createSheet(sheetName); // 从第二个工作簿开始隐藏 this.index++; // 设置隐藏 workbook.setSheetHidden(this.index, true); // 2.循环赋值(为了防止下拉框的行数与隐藏域的行数相对应,将隐藏域加到结束行之后) for (int i = 0, length = v.length; i < length; i++) { // i:表示你开始的行数 0表示你开始的列数 proviceSheet.createRow(i).createCell(0).setCellValue(v[i]); } Name category1Name = workbook.createName(); category1Name.setNameName(sheetName); // 4 $A$1:$A$N代表 以A列1行开始获取N行下拉数据 category1Name.setRefersToFormula(sheetName + "!$A$1:$A$" + (v.length)); // 5 将刚才设置的sheet引用到你的下拉列表中,1表示从行的序号1开始(开始行,通常行的序号为0的行是表头),50表示行的序号50(结束行),表示从行的序号1到50,k表示开始列序号和结束列序号 CellRangeAddressList addressList = new CellRangeAddressList(1, 50, k, k); DataValidationConstraint constraint8 = helper.createFormulaListConstraint(sheetName); DataValidation dataValidation3 = helper.createValidation(constraint8, addressList);
// 阻止输入非下拉选项的值
dataValidation3.setErrorStyle(DataValidation.ErrorStyle.STOP);
dataValidation3.setShowErrorBox(true);
dataValidation3.setSuppressDropDownArrow(true);
dataValidation3.createErrorBox("提示", "此值与单元格定义格式不一致");
// validation.createPromptBox("填写说明:","填写内容只能为下拉数据集中的单位,其他单位将会导致无法入仓");
writeSheetHolder.getSheet().addValidationData(dataValidation3);
});
}
}
调用:
EasyExcel.write(response.getOutputStream()).head(outDto.getHeadList()) .registerWriteHandler(new CustomSheetWriteHandler(map)).registerWriteHandler(new Custemhandler()) .sheet("导出模板").doWrite(outDto.getDataList());