easy excel 导入导出

随笔记录通过easy excel实现导入导出

第一步：导入依赖

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>easyexcel</artifactId>
    <version>3.1.0</version>
</dependency>

第二步：创建导入导出工具类

public class ExcelUtil {
    /**
     * 导出数据为excel文件
     *
     * @param filename       文件名称
     * @param sheetName      sheet名称
     * @param dataResult     集合内的bean对象类型要与clazz参数一致
     * @param clazz          集合内的bean对象类型要与clazz参数一致
     * @param response       HttpServlet响应对象
     */
//有实体对象的导出方式
    public static void export(String filename,String sheetName, List<?> dataResult, Class<?> clazz, HttpServletResponse response) {
        response.setStatus(200);
        response.setContentType("application/vnd.ms-excel");
        response.setCharacterEncoding("utf-8");
        OutputStream outputStream = null;
        ExcelWriter excelWriter = null;
        try {
            if (StringUtil.isEmpty(filename)) {
                throw new RuntimeException("'filename' 不能为空");
            }
            String fileName = filename.concat(".xls");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
            outputStream = response.getOutputStream();

            // 根据不同的策略生成不同的ExcelWriter对象
            if (dataResult == null){
                excelWriter = getTemplateExcelWriter(outputStream);
            } else {
                excelWriter = getExportExcelWriter(outputStream);
            }

            //获取表头个数
            int last = clazz.getDeclaredFields().length;

            WriteSheet writeSheet = EasyExcel.writerSheet(sheetName).head(clazz)
                    .relativeHeadRowIndex(1)
                    .registerWriteHandler(new MonthSheetWriteHandler(sheetName,last))//设置大标题名称及其单元格合并
                    .registerWriteHandler(new LongestMatchColumnWidthStyleStrategy())//自适应列宽
                    .build();
            // 写出数据
            excelWriter.write(dataResult,writeSheet);

        } catch (Exception e) {
            log.error("导出excel数据异常：", e);
            throw new RuntimeException(e);
        } finally {
            if (excelWriter != null) {
                excelWriter.finish();
            }
            if (outputStream != null) {
                try {
                    outputStream.flush();
                    outputStream.close();
                } catch (IOException e) {
                    log.error("导出数据关闭流异常", e);
                }
            }
        }
    }
//没有实体对象的导出方式
    public static void export(String filename,String sheetName,String headName, List<?> dataResult, List<List<String>> head, HttpServletResponse response) {
        response.setStatus(200);
        response.setContentType("application/vnd.ms-excel");
        response.setCharacterEncoding("utf-8");
        OutputStream outputStream = null;
        ExcelWriter excelWriter = null;
        try {
            if (StringUtil.isEmpty(filename)) {
                throw new RuntimeException("'filename' 不能为空");
            }
            String fileName = filename.concat(".xls");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
            outputStream = response.getOutputStream();

            // 根据不同的策略生成不同的ExcelWriter对象
            if (dataResult == null){
                excelWriter = getTemplateExcelWriter(outputStream);
            } else {
                excelWriter = getExportExcelWriter(outputStream);
            }


            WriteSheet writeSheet = EasyExcel.writerSheet(sheetName).head(head)
                    .relativeHeadRowIndex(1)
                    .registerWriteHandler(new MonthSheetWriteHandler(headName,head.size()))//设置大标题名称及其单元格合并
                    .registerWriteHandler(new LongestMatchColumnWidthStyleStrategy())//自适应列宽
                    .build();
            // 写出数据
            excelWriter.write(dataResult,writeSheet);

        } catch (Exception e) {
            log.error("导出excel数据异常：", e);
            throw new RuntimeException(e);
        } finally {
            if (excelWriter != null) {
                excelWriter.finish();
            }
            if (outputStream != null) {
                try {
                    outputStream.flush();
                    outputStream.close();
                } catch (IOException e) {
                    log.error("导出数据关闭流异常", e);
                }
            }
        }
    }


    /**
     * 根据不同策略生成不同的ExcelWriter对象， 可根据实际情况修改
     * @param outputStream  数据输出流
     * @return  模板下载ExcelWriter对象
     */
    private static ExcelWriter getTemplateExcelWriter(OutputStream outputStream){
        return EasyExcel.write(outputStream)
                //.registerWriteHandler(new CommentWriteHandler())        //增加批注策略
                //.registerWriteHandler(new CustomSheetWriteHandler())    //增加下拉框策略
                .registerWriteHandler(getStyleStrategy())               //字体居中策略
                .build();
    }

    /**
     * 根据不同策略生成不同的ExcelWriter对象， 可根据实际情况修改
     * @param outputStream  数据输出流
     * @return  数据导出ExcelWriter对象
     */
    private static ExcelWriter getExportExcelWriter(OutputStream outputStream){
        return EasyExcel.write(outputStream)
                .registerWriteHandler(getStyleStrategy())   //字体居中策略
                .build();
    }

    /**
     *  设置表格内容居中显示策略
     * @return
     */
    private static HorizontalCellStyleStrategy getStyleStrategy(){
        WriteCellStyle headWriteCellStyle = new WriteCellStyle();

        headWriteCellStyle.setFillForegroundColor(IndexedColors.WHITE.index);
        //设置头字体
        WriteFont headWriteFont = new WriteFont();
        headWriteFont.setFontHeightInPoints((short)10);
        headWriteFont.setBold(true);
        headWriteCellStyle.setWriteFont(headWriteFont);
        headWriteFont.setFontName("宋体");
        //设置头居中
        headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);

        // 内容策略
        WriteCellStyle writeCellStyle = new WriteCellStyle();
        // 设置内容水平居中
        writeCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);

        //垂直居中,水平居中
        writeCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        writeCellStyle.setBorderLeft(BorderStyle.THIN);
        writeCellStyle.setBorderTop(BorderStyle.THIN);
        writeCellStyle.setBorderRight(BorderStyle.THIN);
        writeCellStyle.setBorderBottom(BorderStyle.THIN);
        writeCellStyle.setWriteFont(headWriteFont);

        //设置 自动换行
        //contentWriteCellStyle.setWrapped(true);

        return new HorizontalCellStyleStrategy(headWriteCellStyle, writeCellStyle);
    }

    /**
     * 根据Excel模板，批量导入数据
     * @param file  导入的Excel
     * @param clazz 解析的类型
     * @return  解析完成的数据
     */
    public static List<?> importExcel(MultipartFile file, Class<?> clazz){
        if (file == null || file.isEmpty()){
            throw new RuntimeException("没有文件或者文件内容为空！");
        }
        List<Object> dataList = null;
        BufferedInputStream ipt = null;
        try {
            InputStream is = file.getInputStream();
            // 用缓冲流对数据流进行包装
            ipt = new BufferedInputStream(is);
            // 数据解析监听器
            ExcelListener listener = new ExcelListener();
            // 读取数据
            EasyExcel.read(ipt, clazz,listener).headRowNumber(2).sheet().doRead();
            // 获取去读完成之后的数据
            dataList = listener.getDatas();
        } catch (Exception e){
            log.error(String.valueOf(e));
            throw new RuntimeException("数据导入失败！" + e);
        }
        return dataList;
    }
}
第三步：表格头部设置

public class MonthSheetWriteHandler implements SheetWriteHandler {
    private String titleName="";
    private int last=0;

    public MonthSheetWriteHandler(String titleName,int last){
        this.titleName=titleName;
        this.last=last;
    }
    @Override
    public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {

        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(titleName+"表");
        CellStyle cellStyle = workbook.createCellStyle();
        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);
        sheet.addMergedRegionUnsafe(new CellRangeAddress(0, 0, 0, last));
    }
}
第四步：创建导入的监听器

public class ExcelListener extends AnalysisEventListener {
    //可以通过实例获取该值
    private List<Object> datas = new ArrayList<>();
    @Override
    public void invoke(Object o, AnalysisContext analysisContext) {
        datas.add(o);//数据存储到list，供批量处理，或后续自己业务逻辑处理。
        doSomething(o);//根据自己业务做处理
    }

    private void doSomething(Object object) {
        //1、入库调用接口
    }

    public List<Object> getDatas() {
        return datas;
    }

    public void setDatas(List<Object> datas) {
        this.datas = datas;
    }

    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
        // datas.clear();//解析结束销毁不用的资源
    }
}
第五步：service层调用导入导出方法

//导出
/**

fileName:文件名称

sheetName:sheet名称

exportList:数据源
HouseExportVO.class:实体类对象，与数据源对应
response:HttpServlet响应对象

*/

//ExcelUtil.export(fileName,sheetName,exportList, HouseExportVO.class, response); 有实体类对象的调用方式

/**

fileName:文件名称

sheetName:sheet名称

headName:头部标题名称

dataList：数据源组装

headList：动态头部列组装

response:HttpServlet响应对象

*/

//ExcelUtil.export(fileName,sheetName,headName,dataList, headList, response);动态列调用方式

//导入

//读取文件，获取数据
/**

multipartFile:导入的文件，由前端传入

HouseImportExcelDTO.class：接受数据所对应的实体对象

读取到的数据源：excelData

*/
//List<?> excelData = ExcelUtil.importExcel(multipartFile, HouseImportExcelDTO.class);

自此通用的easyExcel导入导出就完成了，具体导出的表格样式自行设置！