二、 EasyExcel 文件模板 - 数据的导入/导出

二、 EasyExcel 文件模板 - 数据的导入/导出

为了满足业务需要，我们大多都自行封装对应的工具类，废话不多说，直接进入正篇。

1. 定义Excel的默认列宽

package com.rocia.entity.export;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.style.column.AbstractColumnWidthStyleStrategy;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;

import java.util.List;

public class CellStyle extends AbstractColumnWidthStyleStrategy {
   
   

    @Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head,
                                  Integer relativeRowIndex, Boolean isHead) {
   
   
        // 简单设置
        Sheet sheet = writeSheetHolder.getSheet();
        sheet.setColumnWidth(cell.getColumnIndex(), 5000);
    }

}

2. 定义动态表头实体

package com.rocia.entity.export;

import java.util.List;

public class DynamicHeader {
   
   

    private String fieldName;

    private String headName;

    private List<DynamicHeader> children;

    public DynamicHeader() {
   
   
    }

    public DynamicHeader(String fieldName, String headName) {
   
   
        this.fieldName = fieldName;
        this.headName = headName;
    }



    public String getFieldName() {
   
   
        return fieldName;
    }

    public void setFieldName(String fieldName) {
   
   
        this.fieldName = fieldName;
    }

    public String getHeadName() {
   
   
        return headName;
    }

    public void setHeadName(String headName) {
   
   
        this.headName = headName;
    }

    public List<DynamicHeader> getChildren() {
   
   
        return children;
    }

    public void setChildren(List<DynamicHeader> children) {
   
   
        this.children = children;
    }
}

3. 自定义表头中内容的样式等设置项

package com.rocia.handler;

import com.alibaba.excel.write.handler.SheetWriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;

public class CustomTitleWriteHandler implements SheetWriteHandler {
   
   
    /**
     * 标题
     */
    private final String fileName;

    /**
     * 字段个数
     */
    private final Integer count;

    public CustomTitleWriteHandler(Integer count, String fileName) {
   
   
        this.fileName = fileName;
        this.count = count;
    }

    @Override
    public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
   
   

    }

    @Override
    public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
   
   
        // 获取clazz所有的属性
        Workbook workbook = writeWorkbookHolder.getWorkbook();
        Sheet sheet = workbook.getSheetAt(0);
        Row row1 = sheet.createRow(0);
        row1.setHeight((short) 800);
        Cell cell = row1.createCell(0);
        //设置标题
        cell.setCellValue(fileName);
        CellStyle cellStyle = workbook.createCellStyle();
        cellStyle.setBorderBottom(BorderStyle.THIN); //下边框
        cellStyle.setBorderLeft(BorderStyle.THIN);//左边框
        cellStyle.setBorderTop(BorderStyle.THIN);//上边框
        cellStyle.setBorderRight(BorderStyle.THIN);//右边框
        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        cellStyle.setAlignment(HorizontalAlignment.CENTER);
        Font font = workbook.createFont();
        font.setBold(true);
        font.setFontHeight((short) 400);
        font.setFontName("宋体");
        cellStyle.setFont(font);
        cell.setCellStyle(cellStyle);
        CellRangeAddress region = new CellRangeAddress(0, 0, 0, count - 1);
        setRegionStyle(sheet, region, cellStyle);
        sheet.addMergedRegion(region);
    }

    /**
     * 为合并的单元格设置样式（可根据需要自行调整）
     */
    public