Question

我正在尝试使用java将目录内容压缩为zip存档。一切都很好，但我只想澄清一些事实。这是我用来压缩文件的代码：

public void pack(@Nonnull String archiveName, @Nonnull File outputDir, @Nonnull File targetDir) {
  File zipFile = new File(outputDir, "out.zip");

  ZipOutputStream zipOutputStream = null;
  OutputStream outputStream;
  try {
    // create stream for writing zip archive
    outputStream = new FileOutputStream(zipFile);
    zipOutputStream = new ZipOutputStream(outputStream);
    // write files recursively
    writeFiles(zipOutputStream, targetDir.listFiles(), "");
  } catch (IOException e) {
    LOGGER.error("IO exception while packing files to archive", e);
  } finally {
    // close output streams
    if (zipOutputStream != null) {
      try {
        zipOutputStream.close();
      } catch (IOException e) {
        LOGGER.error("Unable to close zip output stream", e);
      }
    }
  }
}

/**
 * Writes specified files and their children (in case of directories) to archive
 *
 * @param zipOutputStream archive output stream
 * @param files           which should be added to archive
 * @param path            path relative of root of archive where files should be placed
 */
private void writeFiles(@Nonnull ZipOutputStream zipOutputStream, @Nullable File[] files, @Nonnull String path) throws IOException {
  if (files == null || files.length == 0) {
    return;
  }

  for (File file : files) {
    if (file.isDirectory()) {
      // recursively add files in this directory
      String fullDirectoryName = path + file.getName() + "/";
      File[] childFiles = file.listFiles();
      if (childFiles != null && childFiles.length > 0) {
        // write child files to archive. current directory will be created automatically
        writeFiles(zipOutputStream, childFiles, fullDirectoryName);
      } else {
        // empty directory. write directory itself to archive
        ZipEntry entry = new ZipEntry(fullDirectoryName);
        zipOutputStream.putNextEntry(entry);
        zipOutputStream.closeEntry();
      }
    } else {
      // put file in archive
      BufferedInputStream bufferedInputStream = new BufferedInputStream(new FileInputStream(file));
      zipOutputStream.putNextEntry(new ZipEntry(path + file.getName()));
      ByteStreams.copy(bufferedInputStream, zipOutputStream);
      zipOutputStream.closeEntry();
      bufferedInputStream.close();
    }
  }
}

现在有一些问题：

默认情况下是否正确（在我的情况下）我会得到压缩存档（使用Deflate方法）？
如何获得未压缩的存档：
- 如果我设置方法zipOutputStream.setMethod(ZipOutputStream.STORED)我必须提供大小，压缩大小（是否等于大小？）和crc，否则我将获得异常
- 如果我不想自己计算大小和crc，我可以使用零级别的DEFLATE方法：
```
zipOutputStream.setMethod(ZipOutputStream.DEFLATED);
zipOutputStream.setLevel(ZipOutputStream.STORED);
```
  那么，在这种情况下，我根本没有压缩存档吗？
- 创建未压缩的档案是否有更方便明显的方法？

Answer 1

我没有重新发明轮子，而是认真考虑使用现有的库，例如Apache Ant。创建zip文件的基本习惯是：

Project p = new Project();
p.init();
Zip zip = new Zip();
zip.setProject(p);
zip.setDestFile(new File(outputDir, "out.zip"));
FileSet fs = new FileSet();
fs.setProject(p);
fs.setDirectory(targetDir);
zip.addFileset(fs);
zip.perform();

默认情况下，您将获得压缩存档。对于未压缩的zip，您需要添加的是

zip.setCompress(false);

在setDestFile之后（事实上在perform之前的任何地方）。

压缩zip存档

1 个答案: