项目实战 | Excel导出功能

项目实战 | Excel导出功能

官方文档：关于Easyexcel | Easy Excel (alibaba.com)

一、Excel模板填充导出

场景：将每个教师的教案数据都导出到各个以教师命名的sheet

难点：怎么根据教师数据，生成多个以教师名命名sheet的Excel模板去填充？

解决方式：

1、生成Excel模板的输入IO流：

①pom.xml配置

    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>easyexcel</artifactId>
        <version>2.2.6</version>
    </dependency>
	<dependency>
	  <groupId>org.apache.poi</groupId>
	  <artifactId>poi</artifactId>
	  <version>3.17</version>
	</dependency>
	<dependency>
	  <groupId>org.apache.poi</groupId>
	  <artifactId>poi-ooxml</artifactId>
	  <version>3.17</version>
	</dependency>

②通过基础Excel模板，动态生成多个sheet的Excel模板流

基础Excel模板：

动态生成多个sheet的excel模板流的代码：

private InputStream getTemplateIn(String fileName,List<TeachPlanList> teachPlanLists) throws IOException {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    //原模板只有一个sheet，通过poi复制出需要的sheet个数的模板
    XSSFWorkbook workbook = new XSSFWorkbook(new ClassPathResource(fileName).getInputStream());
    //设置模板的第一个sheet的名称
    String sheet =teachPlanLists.get(0).getUserName()+"-"+ teachPlanLists.get(0).getUserId();
    workbook.setSheetName(0,sheet);
    for (int i = 1; i < teachPlanLists.size(); i++) {
        //复制模板，得到第i个sheet
        workbook.cloneSheet(0,teachPlanLists.get(i).getUserName()+"-"+teachPlanLists.get(i).getUserId());
    }
    //写到流里
    workbook.write(bos);
    byte[] bArray = bos.toByteArray();
    return new ByteArrayInputStream(bArray);
}

2、将生成的Excel输入流当做模板，进行数据填充，导出Excel

public void exportTeachingPlanList(String schoolID, HttpServletResponse response) throws IOException {
    List<TeachPlanList> teachPlanLists =teachPlanMgrBaseInfoMapper.selectTeachPlanBySchoolId(schoolID);
    String fileName = URLEncoder.encode("个人教案库统计数据", "UTF-8");
    response.setHeader("Content-Disposition", "attachment;filename=" + fileName + ".xls");

    InputStream is = getTemplateIn("excel/TeachPlanData.xlsx",teachPlanLists);
    ExcelWriter excelWriter = EasyExcel.write(response.getOutputStream())
        .withTemplate(is)
        .registerConverter(new FileSizeConverter())
        .build();

    for (int i = 0; i < teachPlanLists.size(); i++) {
        WriteSheet writeSheet = EasyExcel.writerSheet(i).build();
        excelWriter.fill(teachPlanLists.get(i).getTeachPlanExcelInfoList(), writeSheet);
        //填充单独统计数据
        Map<String, Object> map = new HashMap<>(2);
        map.put("userName", teachPlanLists.get(i).getUserName());
        map.put("countTeachPlan", teachPlanLists.get(i).getCountTeachPlan());
        //填充列表数据
        excelWriter.fill(map, writeSheet);
    }
    excelWriter.finish();
}

3、导出结果展示：

二、由对象写成Excel

场景：将数据进行统计导出成文档

1、构造Excel导出对象

@Data
@AllArgsConstructor
@NoArgsConstructor
public class ShareTpExcelInfo {
    

    @ExcelProperty("共享者名称")
    @ColumnWidth(15)
    private String sharerName;

    @ExcelProperty("分享教案个数")
    @ColumnWidth(15)
    private Integer sharerCount;

    @ExcelProperty("分享教案被使用次数")
    @ColumnWidth(15)
    private Integer useCount;

    @ExcelProperty("分享教案平均被使用次数")
    @ColumnWidth(15)
    @JSONField(name="AvgUseCount")
    private Double avgUseCount;

}

2、导出成Excel

public void exportShareTpExcel(HttpServletResponse response, List<ShareTpExcelInfo> list) throws IOException {
    
   response.setContentType("application/vnd.ms-excel");
   response.setCharacterEncoding("utf-8");
   String fileName = URLEncoder.encode("共享教案库数据" + System.currentTimeMillis(), String.valueOf(StandardCharsets.UTF_8));
   response.setHeader("Content-Disposition", "attachment;filename=" + fileName + ".xlsx");
   EasyExcel.write(response.getOutputStream(), ShareTpExcelInfo.class).sheet("教案数据").doWrite(list);

}

3、导出结果