JAVA基础必备功能之导出ZIP文件

导出ZIP文件

比较常用的两种：
导出图片压缩文件，导出excel压缩文件;

导出思路：需要导出的文件转存为byte数组保存到Map，然后遍历压缩成zip

需要引入jar：

<!-- 导出zip格式文件 -->
<dependency>
	<groupId>org.apache.commons</groupId>
	<artifactId>commons-compress</artifactId>
	<version>1.12</version>
</dependency>

一、导出图片压缩文件

    /**
     * 图片到byte数组
     * @param imageUrl
     * @param imageName
     * @return
     */
    public static byte[] imgageToByte(String imageUrl, String imageName) throws IOException {
        File imageFile = new File(imageUrl + File.separator + imageName);
        if(!imageFile.exists()){
            log.error("---imgageToByte--imageUrl([{}])--is--null", imageUrl);
            return null;
        }
//        return Files.readAllBytes(imageFile.toPath()); // 不推荐
        FileInputStream fis = new FileInputStream(imageFile);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        byte[] b = new byte[1024];
        int n;
        while ((n = fis.read(b)) != -1) {
            bos.write(b, 0, n);
        }
        byte[] imagetByte = bos.toByteArray();
        fis.close();
        bos.close();
        return imagetByte;
    }

    /**
     * 输出zip格式文件
     * @param response
     * @param zipName zip文件名称
     * @param zipMap  压缩的图片信息
     */
    public static void fileTozip(HttpServletResponse response, String zipName, Map<String, byte[]> zipMap) {
        try{
            response.setHeader("Content-Disposition", "attachment; filename=" + zipName);
            ServletOutputStream outputStream = response.getOutputStream();
            ZipArchiveOutputStream zipOutputStream = new ZipArchiveOutputStream(outputStream);
            zipOutputStream.setUseZip64(Zip64Mode.AsNeeded);
            for(String fileName: zipMap.keySet()){
                ArchiveEntry archiveEntry = new ZipArchiveEntry(fileName);
                zipOutputStream.putArchiveEntry(archiveEntry);
                byte[] fileByte = zipMap.get(fileName);
                zipOutputStream.write(fileByte);
                zipOutputStream.closeArchiveEntry();
            }
            zipOutputStream.close();
            outputStream.close();
        }catch (Exception e){
            log.error("fileTozip error:[{}]", ExceptionUtils.getStackTrace(e));
        }
    }

二、导出excel压缩文件

把csv文件转为byte数组，然后再通过fileTozip方法输出zip文件即可

/**
 * 写CSV并转换为字节流
 * @param headers 表头
 * @param cellList 表数据
 * @return
 */
public static byte[] writeCsvAfterToBytes(String[] headers,List<Object[]> cellList) {
    byte[] bytes = new byte[0];
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    OutputStreamWriter outputStreamWriter = new OutputStreamWriter(byteArrayOutputStream, Charset.forName("UTF-8"));
    BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);
    CSVPrinter csvPrinter = null;
    try {
        //创建csvPrinter并设置表格头
        csvPrinter = new CSVPrinter(bufferedWriter, CSVFormat.DEFAULT.withHeader(headers));
        //写数据
        csvPrinter.printRecords(cellList);
        csvPrinter.flush();
        bytes = byteArrayOutputStream.toString("UTF-8").getBytes();
    } catch (IOException e) {
        log.error("writeCsv IOException:{}", e.getMessage(), e);
    } finally {
        try {
            if (csvPrinter != null) {
                csvPrinter.close();
            }
            if (bufferedWriter != null) {
                bufferedWriter.close();
            }
            if (outputStreamWriter != null) {
                outputStreamWriter.close();
            }
            if (byteArrayOutputStream != null) {
                byteArrayOutputStream.close();
            }
        } catch (IOException e) {
            log.error("iostream close IOException:{}", e.getMessage(), e);
        }
    }
    return bytes;
}