spring boot 根据easyexcel导出excel 设置下拉框（字典值）

在Spring Boot中使用EasyExcel导出Excel并设置下拉框（字典值），你可以通过自定义ExcelWriteHandler来实现。以下是一个简化的例子：

import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.write.metadata.WriteSheet;
import com.alibaba.excel.write.handler.AbstractColumnWidthStyleStrategy;
import com.alibaba.excel.write.handler.ExcelWriteHandler;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddressList;
 
import java.util.List;
 
public class DictionaryDropdownHandler implements ExcelWriteHandler {
 
    private int sheetNum; // 当前sheet的序号
    private int startRow; // 开始行
    private int endRow; // 结束行
    private int colIndex; // 需要设置下拉的列索引
    private List<String> dictionary; // 字典列表
 
    public DictionaryDropdownHandler(int sheetNum, int startRow, int endRow, int colIndex, List<String> dictionary) {
        this.sheetNum = sheetNum;
        this.startRow = startRow;
        this.endRow = endRow;
        this.colIndex = colIndex;
        this.dictionary = dictionary;
    }
 
    @Override
    public void beforeSheetCreate(WriteSheet writeSheet) {
        // 在这里不需要做任何操作
    }
 
    @Override
    public void afterSheetCreate(WriteSheet writeSheet, Sheet sheet) {
        if (sheet.getWorkbook().getSheetIndex(sheet) == sheetNum) {
            DataValidationHelper helper = sheet.getDataValidationHelper();
            DataValidationConstraint constraint = helper.createExplicitListConstraint(dictionary.toArray(new String[0]));
            CellRangeAddressList addressList = new CellRangeAddressList(startRow, endRow, colIndex, colIndex);
            DataValidation dataValidation = helper.createValidation(constraint, addressList);
            sheet.addValidationData(dataValidation);
        }
    }
}
 
// 使用示例
List<List<String>> data = ...; // 数据
List<String> dictionary = Arrays.asList("字典1", "字典2", "字典3"); // 字典值
String fileName = "example.xlsx";
 
EasyExcel.write(fileName, List.class)
        .registerWriteHandler(new DictionaryDropdownHandler(0, 1, 100, 0, dictionary)) // 假设是第一个sheet，数据从第二行开始，设置第一列的下拉列表
        .sheet("Sheet1")
        .doWrit