java创建excel实现下拉框联动

Java可以使用Apache POI库来创建Excel文档。下面是一个简单的示例，说明如何使用POI创建具有下拉框联动的Excel文档：

import java.io.FileOutputStream;
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.xssf.usermodel.XSSFDataValidation;
import org.apache.poi.xssf.usermodel.XSSFDataValidationConstraint;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExcelDropdown {
   public static void main(String[] args) throws Exception {
      Workbook wb = new XSSFWorkbook();
      Sheet sheet1 = wb.createSheet("Sheet1");
      Sheet sheet2 = wb.createSheet("Sheet2");

      String[] data1 = {"A", "B", "C"};
      String[] data2 = {"1", "2", "3"};

      // Create named range for data1
      Name namedRange1 = wb.createName();
      namedRange1.setNameName("data1");
      namedRange1.setRefersToFormula("Sheet1!$A$1:$A$" + data1.length);
      // Create named range for data2
      Name namedRange2 = wb.createName();
      namedRange2.setNameName("data2");
      namedRange2.setRefersToFormula("Sheet2!$A$1:$A$" + data2.length);

      // Create dropdown in cell A1 in sheet1
      DataValidationHelper validationHelper = sheet1.getDataValidationHelper();
      DataValidationConstraint validationConstraint1 = validationHelper.createFormulaListConstraint("data1");
      DataValidationConstraint validationConstraint2 = validationHelper.createFormulaListConstraint("INDIRECT(CONCATENATE(\"data\",A1))");
      DataValidation dropdown1 = validationHelper.createValidation(validationConstraint1, sheet1.getSheetName() + "!$A$1");
      DataValidation dropdown2 = validationHelper.createValidation(validationConstraint2, sheet1.getSheetName() + "!$B$1");
      sheet1.addValidationData(dropdown1);
      sheet1.addValidationData(dropdown2);

      // Create dropdown in cell A1 in sheet2
      DataValidation dropdown3 = validationHelper.createValidation(validationConstraint2, sheet2.getSheetName() + "!$A$1");
      sheet2.addValidationData(dropdown3);

      // Fill data in sheet1
      for (int i = 0; i < data1.length; i++) {
         sheet1.createRow(i).createCell(0).setCellValue(data1[i]);
      }

      // Fill data in sheet2
      for (int i = 0; i < data2.length; i++) {
         sheet2.createRow(i).createCell(0).setCellValue(data2[i]);
      }

      // Write the output to a file
      FileOutputStream fileOut = new FileOutputStream("dropdown.xlsx");
      wb.write(fileOut);
      fileOut.close();
   }
}

此代码创建了一个名为“dropdown.xlsx”的Excel文档，其中包含两个工作表，“Sheet1”和“Sheet2”。“Sheet1”中的单元格A1和B1包含下拉框，可以从“data1”和“data2”中选择。选择的值决定了在单元格B1中显示的下拉框选项。在“Sheet2”中，单元格A1包含一个下拉框，可以从单元格A1中选择的值来自“data1”和“data2”的联合列表。