字符串的 Java 7zip 压缩

Question

我想将 Java 中手动定义的字符串压缩为 7z。这样我就可以将它转换为 base64。我发现许多示例将文件压缩到 7z，然后保存到新文件中。

我只是尝试下一个代码，它正确地获取文件并压缩它:

private static void addToArchiveCompression(SevenZOutputFile out, File file, String dir) throws IOException {
        String name = dir + File.separator + file.getName();
        if (file.isFile()){
            SevenZArchiveEntry entry = out.createArchiveEntry(file, name);
            out.putArchiveEntry(entry);

            FileInputStream in = new FileInputStream(file);
            byte[] b = new byte[1024];
            int count = 0;
            while ((count = in.read(b)) > 0) {
                out.write(b, 0, count);
            }
            out.closeArchiveEntry();

        } else if (file.isDirectory()) {
            File[] children = file.listFiles();
            if (children != null){
                for (File child : children){
                    addToArchiveCompression(out, child, name);
                }
            }
        } else {
            System.out.println(file.getName() + " is not supported");
        }
    }  

但是如何将手动定义的字符串压缩为 7z 并将其转换为 byte[]？那么我可以将 byte[] 转换为 base64 并打印它，而无需生成或读取新文件？

Answer 1

因为您已经在使用 commons-compress对于 7zip 压缩，您可以使用 SeekableInMemoryByteChannel 创建 SevenZOutputFile(SeekableByteChannel) 实例包装一个字节数组。根据 javadoc:

A SeekableByteChannel implementation that wraps a byte[].

When this channel is used for writing an internal buffer grows to accommodate incoming data. A natural size limit is the value of Integer.MAX_VALUE. Internal buffer can be accessed via array().

类似于:

SeekableInMemoryByteChannel channel = new SeekableInMemoryByteChannel(new byte[1024]);
SevenZOutputFile out = new SevenZOutputFile(channel);
// modified addToArchiveCompression(out, ...); for String
// encode channel.array() to Base64