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文件处理

admin 11月 23, 2020 0

记录一下在文件处理里面遇到的问题

读excel大文件

依赖添加

git地址

<dependency>
         <groupId>com.monitorjbl</groupId>
         <artifactId>xlsx-streamer</artifactId>
         <version>2.0.0</version>
     </dependency>

示例代码

Workbook workbook = StreamingReader.builder().rowCacheSize(1).bufferSize(4096).open(in);
              Sheet sheet = workbook.getSheetAt(0);
              Row firstRow = sheet.rowIterator().next();
              Iterator<Cell> iterator = firstRow.cellIterator();
              while (iterator.hasNext()) {
                  cellList.add(iterator.next().getStringCellValue());
              }

对输入流进行压缩


 private InputStream (InputStream inputStream, String fileName) {
        byte[] buf = new byte[1024];
        try {
            
//            ZipOutputStream out = new ZipOutputStream(new FileOutputStream("/home/jianganwei/下载/demo_LOCAL.zip"));
            ByteArrayOutputStream byteArrayOutputStream=new ByteArrayOutputStream();
            ZipOutputStream out = new ZipOutputStream(byteArrayOutputStream);
            int len;
            ZipEntry zipEntry = new ZipEntry(fileName);
//            zipEntry.setUnixMode(666);

            out.putNextEntry(zipEntry);
            while ((len = inputStream.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
            out.closeEntry();
            inputStream.close();
            out.close();
           logger.info("压缩完成."+fileName);
            return new ByteArrayInputStream(byteArrayOutputStream.toByteArray());
        } catch (Exception e) {
// TODO Auto-generated catch block
            e.printStackTrace();
            return null;
        }
    }

<!-- https://mvnrepository.com/artifact/org.apache.ant/ant -->
   <dependency>
       <groupId>org.apache.ant</groupId>
       <artifactId>ant</artifactId>
       <version>1.9.3</version>
   </dependency>