SpringBoot学习小结之EasyExcel

前言

java处理excel表格常用的框架库有: jxl，POI, EasyExcel，EasyPoi, hutool。

• jxl , 韩国人开发的一套解析excel Java库，不支持xlsx。09年后一直没有更新，功能比较少。
• POI，apache提供的一套java解析office工具，包含excel。我之前有一篇博文介绍了一些POI中关于Excel API使用
• EasyExcel，阿里开源的JAVA解析Excel工具，对于POI解析耗内存进行了优化
• EasyPoi，对POI进行封装的一套工具库，简化POI代码编写
• hutool，国人开发的工具库，其中包含excel的读写

最主要还是POI, 后三个都依赖于它。由于工作中项目重点使用阿里的EasyExcel,以下重点介绍EasyExcel

一、EasyExcel

以一个进销存表格为例子，演示EasyExcel如何导入导出Excel。下面是Excel模板实体，需要先导入pom依赖

@Data
public class InventoryItem {

    @ExcelIgnore
    private Integer id;
    @ExcelProperty(index = 0, value = {"序号", "序号"})
    private String no;
    @ExcelProperty(index = 1, value = { "商品名称","商品名称"})
    private String productName;
    @ExcelProperty(index = 2, value = {"规格", "规格"})
    private String spec;
    @ExcelProperty(index = 3, value = {"单位", "单位"})
    private String unit;

    @ExcelProperty(index = 4, value = {"上月结存","数量"})
    private String lastMonthStoreNum;
    @ExcelProperty(index = 5, value = {"上月结存","单价"})
    private String lastMonthStoreUnitPrice;
    @ExcelProperty(index = 6, value = {"上月结存","金额"})
    private String lastMonthStoreMount;

    @ExcelProperty(index = 7, value = {"本月购入","数量"})
    private String thisMonthPurchaseNum;
    @ExcelProperty(index = 8, value = {"本月购入","单价"})
    private String thisMonthPurchaseUnitPrice;
    @ExcelProperty(index = 9, value = {"本月购入","金额"})
    private String thisMonthPurchaseMount;

    @ExcelProperty(index = 10, value = {"本月发出","数量"})
    private String thisMonthSendNum;
    @ExcelProperty(index = 11, value = {"本月发出","单价"})
    private String thisMonthSendUnitPrice;
    @ExcelProperty(index = 12, value = {"本月发出","金额"})
    private String thisMontSendhMount;

    @ExcelProperty(index = 13, value = {"本月结存","数量"})
    private String thisMonthStoreNum;
    @ExcelProperty(index = 14, value = {"本月结存","单价"})
    private String thisMonthStoreUnitPrice;
    @ExcelProperty(index = 15, value = {"本月结存","金额"})
    private String thisMonthStoreMount;

    @ExcelProperty(index = 16, value = {"月末盘点数量", "月末盘点数量"})
    private String endOfMonthCheckNum;
    @ExcelProperty(index = 17, value = {"差额", "差额"})
    private String diff;
}

1.1 pom依赖

        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>easyexcelartifactId>
            <version>2.2.3version>
        dependency>

1.2 导入

• 读取Excel需要设置监听器

  public class InventoryItemAnalysis extends AnalysisEventListener<InventoryItem> {
  
      List<InventoryItem> list = new ArrayList<>();
      @Override
      public void invoke(InventoryItem data, AnalysisContext context) {
          list.add(data);
      }
  
      @Override
      public void doAfterAllAnalysed(AnalysisContext context) {
      }
  
      public List<InventoryItem> getList() {
          return list;
      }
  
      public void setOtnList(List<InventoryItem> list) {
          this.list = list;
      }
  }
  

• 本地环境可以根据文件路径读取

  
  InventoryItemAnalysis analysis = new InventoryItemAnalysis();
  EasyExcel.read("C:\\Users\\root\\Desktop\\进销存.xlsx", InventoryItem.class, analysis ).sheet().doRead();
  System.out.println(analysis.getList());
  

• 在web环境下可以用流读取

  @PostMapping("/upload")
  @ResponseBody
  public Object excelImport(@RequestParam("uploadFile") MultipartFile file
              ) throws Exception {
  	InventoryItemAnalysis analysis = new InventoryItemAnalysis();
  	EasyExcel.read(file.getInputStream(), InventoryItem.class, analysis).sheet().doRead();
  	return analysis.getList();
  }
  
  

1.3 导出

• 本地导出

  EasyExcel.write("C:\\Users\\root\\Desktop\\进销存导出.xlsx", InventoryItem.class).sheet().doWrite(analysis.getList());
  

• web导出

  @GetMapping("/download")
  public void download(HttpServletResponse response) {
  	String fileName = "进销存数据.xlsx";
  	List<InventoryItem> list = new ArrayList<>();
  	setResponseHeader(response, fileName);
  	try {
  	EasyExcel.write(response.getOutputStream(), InventoryItem.class)
  	                    .sheet("总表").doWrite(list);
  	} catch (IOException e) {
  	e.printStackTrace();
  	}
  }
  private void setResponseHeader(HttpServletResponse response, String fileName) {
  	try {
      	response.setContentType("application/octet-stream;charset=ISO8859-1");
          response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName,"UTF-8"));
          response.addHeader("Pargam", "no-cache");
          response.addHeader("Cache-Control", "no-cache");
       } catch (Exception ex) {
              ex.printStackTrace();
      }
  }
  

  

1.4 自定义样式或内容

• EasyExcel默认样式不美观，需要自定义样式。EasyExcel提供一个类HorizontalCellStyleStrategy，可用来配置一些表头和内容样式。

  public static WriteHandler headStyle() {
  		// 头部样式策略
          WriteCellStyle headWriteCellStyle = new WriteCellStyle();
          headWriteCellStyle.setFillForegroundColor(IndexedColors.WHITE1.getIndex());
          WriteFont headWriteFont = new WriteFont();
          headWriteFont.setFontHeightInPoints((short) 12);
          headWriteFont.setBold(false);
          headWriteCellStyle.setWriteFont(headWriteFont);
  
          // 内容样式策略
          WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
          contentWriteCellStyle.setWrapped(true);
          contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
          // 设置内容边框样式
          contentWriteCellStyle.setBorderLeft(THIN);
          contentWriteCellStyle.setBorderTop(THIN);
          contentWriteCellStyle.setBorderRight(THIN);
          contentWriteCellStyle.setBorderBottom(THIN);
  
          HorizontalCellStyleStrategy horizontalCellStyleStrategy = new HorizontalCellStyleStrategy(headWriteCellStyle,
                  contentWriteCellStyle);
          return horizontalCellStyleStrategy;
      }
  

• 更细粒度控制可以通过实现com.alibaba.excel.write.handler.WriteHandler的四个子接口来自定义样式或者内容。注意：多个Handler如果作用在同一个单元格，后面会覆盖前面的样式。

  • com.alibaba.excel.write.handler.CellWriteHandler单元格处理器

    • beforeCellCreate
    • afterCellCreate
    • afterCellDataConverted 一个单元格数据转换后
    • afterCellDispose一个单元格所有操作完成后调用这个方法

  • com.alibaba.excel.write.handler.RowWriteHandler 行处理器

    • beforeRowCreate
    • afterRowCreate
    • afterRowDispose 一行所有操作完成后调用这个方法

  • com.alibaba.excel.write.handler.SheetWriteHandlerSheet处理器

    • beforeSheetCreateSheet
    • afterSheetCreateSheet

  • com.alibaba.excel.write.handler.WorkbookWriteHandler 工作簿处理器

    • beforeWorkbookCreate
    • afterWorkbookCreate
    • afterWorkbookDispose 工作簿所有操作完成后调用这个方法

• 自定义案例

  • 案例1：在表格表头前添加标题等信息

    public class CustomWriteHandler implements SheetWriteHandler {
    
        @Override
        public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
        }
    
        @Override
        public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
            Workbook workbook = writeWorkbookHolder.getWorkbook();
            Sheet sheet = workbook.getSheetAt(0);
            //设置标题
            Row row1 = sheet.createRow(0);
            row1.setHeight((short) 800);
            Cell cell1 = row1.createCell(0);
            cell1.setCellValue("某某公司进销存报表");
            CellStyle cellStyle = workbook.createCellStyle();
            cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
            cellStyle.setAlignment(HorizontalAlignment.CENTER);
            Font font = workbook.createFont();
            font.setBold(true);
            font.setFontHeight((short) 400);
            cellStyle.setFont(font);
            cell1.setCellStyle(cellStyle);
            sheet.addMergedRegionUnsafe(new CellRangeAddress(0, 0, 0, 17));
            //设置填表日期,填报人,联系方式
            Row row2 = sheet.createRow(1);
            row2.setHeight((short) 500);
            row2.createCell(1).setCellValue("填表日期");
            row2.createCell(11).setCellValue("填表人");
            row2.createCell(15).setCellValue("联系方式");
        }
    }
    

    EasyExcel.write(response.getOutputStream(), InventoryItem.class)
                        .sheet("总表").registerWriteHandler(headStyle())
                        .registerWriteHandler(new CustomWriteHandler())
                        .relativeHeadRowIndex(2).doWrite(list);
    

    最终样式

    

• 案例二：报表标颜色
  进销存中上月库存数量小于10字体变红，否则变绿

   public class ColorWriteHandler implements CellWriteHandler {
  
    @Override
    public void beforeCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Head head, Integer columnIndex, Integer relativeRowIndex, Boolean isHead) {
  
    }
  
    @Override
    public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
  
    }
  
    @Override
    public void afterCellDataConverted(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, CellData cellData, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
  
    }
  
    @Override
    public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<CellData> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
        if (!isHead) {
            if (cell.getColumnIndex() == 4) {
                String val = cell.getStringCellValue();
                int num = 0;
                try {
                    num = Integer.parseInt(val);
                } catch (NumberFormatException e) {
                    e.printStackTrace();
                }
                if (num > 10) {
                    setColor(cell, writeSheetHolder, IndexedColors.RED);
                } else {
                    setColor(cell, writeSheetHolder, IndexedColors.GREEN);
                }
            }
        }
    }
    private void setColor(Cell cell, WriteSheetHolder writeSheetHolder, IndexedColors color) {
        Sheet sheet = writeSheetHolder.getSheet();
        Workbook workbook = sheet.getWorkbook();
        Font font = workbook.createFont();
        font.setColor(color.getIndex());
        CellStyle cellStyle = workbook.createCellStyle();
        cellStyle.setFont(font);
        cellStyle.setBorderTop(BorderStyle.THIN);
        cellStyle.setBorderBottom(BorderStyle.THIN);
        cellStyle.setBorderLeft(BorderStyle.THIN);
        cellStyle.setBorderRight(BorderStyle.THIN);
        cell.setCellStyle(cellStyle);
    }
  }
  
  

  public static void main(String[] args) {
  	        List<InventoryItem> list = data();
  	        EasyExcel.write("C:\\Users\\supre\\Desktop\\进销存导出.xlsx", InventoryItem.class)
  	                .registerWriteHandler(normalStyle())
  	                .registerWriteHandler(new ColorWriteHandler())
  	                .sheet().doWrite(list);
  }
  public static List<InventoryItem> data() {
  	List<InventoryItem> list = new ArrayList<>();
  	for (int i = 0; i < 50; i++) {
  		String s = Integer.valueOf(i).toString();
  		InventoryItem inventoryItem = new InventoryItem();
  		inventoryItem.setId(i);
  		inventoryItem.setNo(s);
  		inventoryItem.setLastMonthStoreNum(s);
  		inventoryItem.setProductName("上衣+" + i);
  		list.add(inventoryItem);
  	}
  	return list;
  }
  public static WriteHandler normalStyle() {
  	        // 头部样式策略
  		WriteCellStyle headWriteCellStyle = new WriteCellStyle();
  	    headWriteCellStyle.setFillForegroundColor(IndexedColors.WHITE1.getIndex());
  		WriteFont headWriteFont = new WriteFont();
  		headWriteFont.setFontHeightInPoints((short) 12);
  		headWriteFont.setBold(false);
  		headWriteCellStyle.setWriteFont(headWriteFont);
  	
  		// 内容样式策略
  		WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
  		contentWriteCellStyle.setWrapped(true);
  	    contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
  		// 设置内容边框样式
  		contentWriteCellStyle.setBorderLeft(THIN);
  		contentWriteCellStyle.setBorderTop(THIN);
  		contentWriteCellStyle.setBorderRight(THIN);
  		contentWriteCellStyle.setBorderBottom(THIN);
  	
  		HorizontalCellStyleStrategy horizontalCellStyleStrategy = new HorizontalCellStyleStrategy(headWriteCellStyle,
  		contentWriteCellStyle);
  		return horizontalCellStyleStrategy;
  }
  

  最终样式
  

1.5 模板填充

EasyExcel自2.1.1后提供了更强大的表格填充功能，提供一个模板文件，写一些模板参数，就可以快速生成表格

• 模板

  将Excel实体类的属性用{.属性名}填入模板文件，样式也会被复制。注意：填充List时需要带个点，如果单个就不需要。

  

• 填充

  EasyExcel.write("C:\\Users\\root\\Desktop\\进销存.xlsx")
                  .withTemplate("C:\\Users\\root\\Desktop\\进销存模板.xlsx").sheet().doFill(analysis.getList());
  

  

• 更复杂的填充

  EasyExcel不仅支持竖向填充，还支持横向填充，多列表填充，详细信息可以查看官方文档

参考

1. https://www.yuque.com/easyexcel/doc/easyexcel
2. https://www.yuque.com/easyexcel/doc/fill
3. https://blog.csdn.net/qq_41514643/article/details/106993760