EasyExcel动态导出数据

头的数据格式设置为 List<List<String>>  并且具体的数据格式也设置为List<List<String>>具体的数据和表头一一对应

public <T> void exportTerminalnew(ExportHandlerDS handler, List<String> excelHeaders, String  staffCode, FastFileStorageClient fastFileClient, String fdfsUrl, IReportService reportExportDetailService, Long id) {
        
        ......
                        //根据前端选择的字段生成表头
        List<List<String>> head = head(excelHeaders);
        WriteSheet writeSheet = EasyExcel.writerSheet().head(head).
                //设置样式
                registerWriteHandler(setExcelStyle()).
                //自定义列宽
                registerWriteHandler(new Custemhandler()).
                //registerWriteHandler(new LongestMatchColumnWidthStyleStrategy()).
                //固定表头
                registerWriteHandler(new CustomSheetWriteHandler()).
                        //动态合并单元格
                        registerWriteHandler(new ExcelCellMergeStrategy()).
                build();
        //设置列宽？
        // writeSheet.setColumnWidthMap();
        ExcelWriter excelWriter = EasyExcel.write(baos).excelType(ExcelTypeEnum.XLSX).build();
        WriteTable build = EasyExcel.writerTable(0).needHead(false).build();
       
       .....
       
            //根据传入的字段筛选导出哪些数据
            List<List<String>> body = getBody(list, excelHeaders);
            excelWriter.write(body,writeSheet,build);
            excelWriter.finish();
            StorePath storePath=null;
            if(!selImage){
                final ByteArrayInputStream byteIs = new ByteArrayInputStream(baos.toByteArray());
                //生成的文件上传到fast DFS系统上
                 storePath = fastFileClient.uploadFile(byteIs, byteIs.available(), ExcelTypeEnum.XLSX.getValue().substring(1), null);
            }else {
                StringBuilder fileNewPath=new StringBuilder();
                final ByteArrayInputStream byteIs = new ByteArrayInputStream(getFile(baos,fileNewPath,list,staffCode));
                //生成的文件上传到fast DFS系统上
                storePath = fastFileClient.uploadFile(byteIs, byteIs.available(), "zip", null);
                 // 删除文件夹及文件
                path.add(fileNewPath.toString());
            }
            String fullPath = storePath.getFullPath();
            filePath = fdfsUrl + "/" + fullPath;
            // 1: 执行成功 -1: 执行失败
            if (StringUtils.isNotBlank(fullPath)) {
                reportExportDetailDTO.setStatus(1);
                reportExportDetailDTO.setFilePath(filePath);
            } else {
                reportExportDetailDTO.setStatus(-1);
            }

        } catch (Exception e) {
            reportExportDetailDTO.setStatus(-1);
            log.error("导出Excel报表文件出错",e);
        } finally {
            if(CollectionUtils.isNotEmpty(path)){
                //删除文件
                delFile(path);
                log.error("要删除的目录地址："+path);
            }
            reportExportDetailDTO.setId(id);
            reportExportDetailService.updateExport(reportExportDetailDTO);
        }
    }

**
 * 设置excel样式
 * @return
 */
private HorizontalCellStyleStrategy setExcelStyle(){
    // 表头策略
    WriteCellStyle headWriteCellStyle = new WriteCellStyle();
    WriteFont writeFont=new WriteFont();
    writeFont.setFontName("宋体");
    writeFont.setFontHeightInPoints((short) 11);
    //加粗
    writeFont.setBold(true);
    headWriteCellStyle.setWriteFont(writeFont);
    //内容样式策略
    WriteCellStyle contextWriteeCellStyle=new WriteCellStyle();
    //设置水平居中
    contextWriteeCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
    // 这个策略是 头是头的样式 内容是内容的样式 其他的策略可以自己实现
    HorizontalCellStyleStrategy horizontalCellStyleStrategy =
            new HorizontalCellStyleStrategy(headWriteCellStyle,contextWriteeCellStyle);
    return horizontalCellStyleStrategy;
}

/**
easyexcel提供的自动列宽不能满足需求，只能自己根据业务要求重写

 * @description: EasyExcel设置列宽
 * @author: qiuqingxin
 * @create: 2020-08-07 15:49
 **/
public class Custemhandler extends AbstractColumnWidthStyleStrategy {
    private static final int MAX_COLUMN_WIDTH = 50;
    public Custemhandler() {
    }
    @Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<CellData> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
        int columnWidth=20;
        if (isHead ) {
            if (cell.getStringCellValue().equals("照片类型")){
               columnWidth=20;
            }
            if (cell.getStringCellValue().equals("当前位置")){

                columnWidth=50;
            }
            if (cell.getStringCellValue().equals("备注")){
                columnWidth=30;
            }
           ......
            writeSheetHolder.getSheet().setColumnWidth(cell.getColumnIndex(), columnWidth * 256);

        }
    }
}

/**
 * @description: easyExcel拦截器
 * @author: qiuqingxin
 * @create: 2020-06-16 11:29
 **/
public class CustomSheetWriteHandler implements SheetWriteHandler {
    @Override
    public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {

    }
    @Override
    public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
        //固定表头
            writeSheetHolder.getSheet().createFreezePane(0,1,0,1);
    }
}

/**
 * @description: 自定义合并单元格
 * @author: qiuqingxin
 * @create: 2020-08-07 16:38
 **/
public class ExcelCellMergeStrategy implements CellWriteHandler {
    private int fileColumnIndex = -1;
    private int imageColumnIndex = -1;
    private String  regEx="[^0-9]";

    @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) {

    }
    /**
    每在excel中写入一个单元格数据都会调用次方法
    **/
    @Override
    public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<CellData> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
        if (isHead) {
            if ("附件".equals(cell.getStringCellValue())) {
                fileColumnIndex = cell.getColumnIndex();
                return;
            }
            if ("现场照片".equals(cell.getStringCellValue())) {
                imageColumnIndex = cell.getColumnIndex();
                return;
            }
        } else {

            if (imageColumnIndex != -1) {
                //找到附件所在的列
                if (cell.getColumnIndex() == imageColumnIndex + 1) {
                    // Sheet sheet = writeSheetHolder.getSheet();
                    Row row = cell.getRow();
                    Cell cell1 = row.getCell(imageColumnIndex);
                    Cell cell2 = row.getCell(imageColumnIndex + 1);
                    String imageUrl = cell2.getStringCellValue();
                    String imageName = cell1.getStringCellValue();
                    if (!isZero(imageName)) {
                        cell1.setCellFormula( "HYPERLINK(\"" + imageUrl + "\",\"" + imageName + "\")");
                    }else {
                        cell1.setCellValue("");
                    }
                    row.removeCell(cell2);
                }
            }


            if (fileColumnIndex != -1) {
                if (null == cell.getRow().getCell(fileColumnIndex)) {
                    //找到附件所在的列
                    if (cell.getColumnIndex() == fileColumnIndex + 2) {
                        // Sheet sheet = writeSheetHolder.getSheet();
                        Row row = cell.getRow();
                        Cell cell3 = row.createCell(fileColumnIndex);
                        Cell cell1 = row.getCell(fileColumnIndex + 1);
                        Cell cell2 = row.getCell(fileColumnIndex + 2);
                        String fileUrl = cell2.getStringCellValue();
                        cell3.setCellFormula("HYPERLINK(\"" + fileUrl + "\",\"" + cell1.getStringCellValue() + "\")");
                        row.removeCell(cell1);
                        row.removeCell(cell2);
                    }
                } else {
                    if (cell.getColumnIndex() == fileColumnIndex + 1) {
                        // Sheet sheet = writeSheetHolder.getSheet();
                        Row row = cell.getRow();
                        Cell cell1 = row.getCell(fileColumnIndex );
                        Cell cell2 = row.getCell(fileColumnIndex + 1);
                        String fileUrl = cell2.getStringCellValue();
                        cell1.setCellFormula("HYPERLINK(\"" + fileUrl + "\",\"" + cell1.getStringCellValue() + "\")");
                        row.removeCell(cell2);
                    }
                }


            }

        }

    }

    private boolean isZero(String value){
        Pattern p = Pattern.compile(regEx);
        Matcher m = p.matcher(value);
        String trim = m.replaceAll("").trim();

        return trim.equals("0")?true:false;
    }



}


private List<List<String>> getBody(List<DsTerminalUploadExcel> list3,List<String> excelHeaders )throws Exception{
    Map<Integer,String> map=new HashMap<>();
    List<List<String>> lists=new ArrayList<>();
    Integer index=1;
    for (String excelHeader : excelHeaders) {
        map.put(index++,excelHeader);
    }
    int size = map.size();
    for (DsTerminalUploadExcel dsTerminalUploadExcel : list3) {
        List<String> data=new ArrayList<>();
    for (int i =0;i<size;i++){
        if (map.get(i+1).equals("image")){
            String value2=dsTerminalUploadExcel.getImagePaths()!=null?dsTerminalUploadExcel.getImagePaths().size()+"张)":"0张)";
             value2="点击查看图片("+value2;
            data.add(value2);
            value2=null==dsTerminalUploadExcel.getStaffName()?
                    "/"+dsTerminalUploadExcel.getReportDate().substring(0,10)+"_"+dsTerminalUploadExcel.getId():
                    "/"+dsTerminalUploadExcel.getStaffName()+"_"+dsTerminalUploadExcel.getReportDate().substring(0,10)+"_"+dsTerminalUploadExcel.getId();
            value2="images/"+value2;
            data.add(value2);
        }else {
        String value=(String)getValue(dsTerminalUploadExcel,map.get(i+1));
        data.add(value);
        if (map.get(i+1).equals("fileName")){
            String value2=(String)getValue(dsTerminalUploadExcel,"filePath");
            data.add(value2);
        }
        }
    }
    lists.add(data);
    }
    return lists;
}
//反射调用get方法
public static Object getValue(Object dto,String name) throws Exception {
    String s = name.substring(0, 1).toUpperCase();
    String substring = name.substring(1);

    Method method = dto.getClass().getMethod("get" + s + substring);
    return   method.invoke(dto);
}


//将数据生成字节数组
private byte[] getFile(ByteArrayOutputStream baos,StringBuilder fileNewPath,List<DsTerminalUploadExcel> list3,
                      String staffCode) throws Exception {
    // String path = "D:\\sss\\"+staffCode+"_"+(new SimpleDateFormat("yyMMddHHmmss").format(new Date()))+"\\";
     String path = "/data/file/"+staffCode+"_"+(new SimpleDateFormat("yyMMddHHmmss").format(new Date()))+"/";
    log.error("获取的路径:"+path);
    String fileName=""+System.currentTimeMillis();
    String  filePath=path+fileName;
    fileNewPath.append(path);
    File file = new File(filePath);
    if (!file.exists()){
        file.mkdirs();
    }
    FileOutputStream fileOutputStream=new FileOutputStream(filePath+"/"+System.currentTimeMillis()+ExcelTypeEnum.XLSX.getValue());
    fileOutputStream.write(baos.toByteArray());
    fileOutputStream.close();

        genImages(list3,filePath);
        log.error("filePath"+filePath);

    return setZip(filePath,path,fileName);
}
private void genImages(List<DsTerminalUploadExcel> list3,String filePath) throws Exception {
    File file = new File(filePath + "/images");
    if (!file.exists()){
        file.mkdirs();
    }
    for (DsTerminalUploadExcel dsTerminalUploadExcel : list3) {
        List<String> imagePaths = dsTerminalUploadExcel.getImagePaths();
        if (null==imagePaths||imagePaths.size()==0){
            continue;
        }
        String imagepath=null==dsTerminalUploadExcel.getStaffName()?
                "/"+dsTerminalUploadExcel.getReportDate().substring(0,10)+"_"+dsTerminalUploadExcel.getId():
                "/"+dsTerminalUploadExcel.getStaffName()+"_"+dsTerminalUploadExcel.getReportDate().substring(0,10)+"_"+dsTerminalUploadExcel.getId();
         imagepath=file.getPath()+imagepath;
        File file1 = new File(imagepath);
        if (!file1.exists()) file1.mkdirs();

        for (String imagePath : imagePaths) {
            String ext = imagePath.substring(imagePath.lastIndexOf("/") + 1);
            File file2 = new File(file1.getPath() + "/" + ext);

            FileOutputStream fileOutputStream = new FileOutputStream(file2);
            BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
            //发送HTTP请求并指定返回的数据为byte数组
            RestTemplate restTemplate = new RestTemplate();
            byte[] forObject = restTemplate.getForObject(imagePath, byte[].class);
            bufferedOutputStream.write(forObject);
            bufferedOutputStream.flush();
            fileOutputStream.close();
            bufferedOutputStream.close();
        }
    }
}

private byte[] setZip(String allPath, String path, String fileName) throws Exception {
    String newzipPath = path + fileName + ".zip";
    File file = new File(newzipPath);
    FileOutputStream fileOutputStream = new FileOutputStream(file);
　　　//压缩工具类
    byte[] aByte = ZipUtils.getByte(allPath, fileOutputStream, true, file);
    fileOutputStream.close();
    return aByte;
}