使用 apache common compress/org.tukaani.xz 在 java 中解码 LZMA 压缩 zip 文件的问题

Question

在尝试解码 LZMA 压缩 xls 文件时出现 org.tukaani.xz.UnsupportedOptionsException: Uncompressed size is too big 错误。而非 LZMA 文件可以毫无问题地解包/解码。两种情况下同一个 xls 文件被压缩。

我正在使用 Apache commons compress 和 org.tukaani.xz。

示例代码供参考

package com.concept.utilities.zip;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
import org.apache.commons.compress.archivers.zip.ZipFile;
import org.apache.commons.compress.compressors.lzma.LZMACompressorInputStream;

public class ApacheComm {

    public void extractLZMAZip(File zipFile, String compressFileName, String destFolder) {

        ZipFile zip = null;
        try {

            zip = new ZipFile(zipFile);
            ZipArchiveEntry zipArchiveEntry = zip.getEntry(compressFileName);
            if (null != zipArchiveEntry) {
                String name = zipArchiveEntry.getName();

                // InputStream is = zip.getInputStream(zipArchiveEntry);
                InputStream israw = zip.getRawInputStream(zipArchiveEntry);

                LZMACompressorInputStream lzma = new LZMACompressorInputStream(israw);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (null != zip)
                ZipFile.closeQuietly(zip);
        }
    }

    public static void main(String[] args) throws IOException {

        ApacheComm c = new ApacheComm();
        try {
            c.extractLZMAZip(new File("H:\\archives\\rollLZMA.zip"), "roll.xls", "H:\\archives\\");
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}

错误

org.tukaani.xz.UnsupportedOptionsException: Uncompressed size is too big
    at org.tukaani.xz.LZMAInputStream.initialize(Unknown Source)
    at org.tukaani.xz.LZMAInputStream.<init>(Unknown Source)
    at org.apache.commons.compress.compressors.lzma.LZMACompressorInputStream.<init>(LZMACompressorInputStream.java:50)
    at com.concept.utilities.zip.ApacheComm.extractLZMAZip(ApacheComm.java:209)
    at com.concept.utilities.zip.ApacheComm.main(ApacheComm.java:224)

我错过了什么吗？有没有其他方法可以解码 zip 文件与压缩方法 = LZMA

Answer 1

您的代码不起作用的原因是 Zip LZMA 压缩数据段与普通压缩 LZMA 文件相比具有不同的标头。

您可以在https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT 阅读规范（4.4.4 通用位标志，5.8 LZMA - 方法 14），但要引用重要部分：

5.8.5 [...] LZMA 压缩数据段由 LZMA 属性标头和 LZMA 压缩数据组成，如下所示：

[LZMA properties header for file 1]
[LZMA compressed data for file 1]

[...]

5.8.8 LZMA Properties Header中属性信息的存储字段如下：

LZMA Version Information 2 bytes
LZMA Properties Size 2 bytes
LZMA Properties Data variable, defined by "LZMA Properties Size"

5.8.8.1 LZMA 版本信息 - 此字段标识用于压缩文件的 LZMA SDK 版本。第一个字节存储LZMA SDK的主版本号，第二个字节存储次版本号。

5.8.8.2 LZMA 属性大小 - 此字段定义剩余属性数据的大小。通常这个大小应该由 SDK 的版本决定。包含此大小字段是为了方便并帮助避免将来由于此压缩算法的更改而出现任何歧义。

5.8.8.3 LZMA 属性数据 - 此可变大小字段记录 LZMA SDK 定义的解压缩器所需的值。该字段中存储的数据应该使用“LZMA版本信息”字段定义的SDK版本中的WriteCoderProperties()获取。

代码示例：

import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
import org.apache.commons.compress.archivers.zip.ZipFile;
import org.apache.commons.compress.archivers.zip.ZipMethod;
import org.apache.commons.io.IOUtils;
import org.tukaani.xz.LZMAInputStream;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class ApacheComm
{
    public InputStream getInputstreamForEntry(ZipFile zipFile, ZipArchiveEntry ze) throws IOException
    {
        if (zipFile.canReadEntryData(ze))
        {
            return zipFile.getInputStream(ze);
        } else if (ze.getMethod() == ZipMethod.LZMA.getCode()) {
            InputStream inputStream = zipFile.getRawInputStream(ze);
            ByteBuffer buffer = ByteBuffer.wrap(IOUtils.readFully(inputStream, 9))
                    .order(ByteOrder.LITTLE_ENDIAN);

            // Lzma sdk version used to compress this data
            int majorVersion = buffer.get();
            int minorVersion = buffer.get();

            // Byte count of the following data represent as an unsigned short.
            // Should be = 5 (propByte + dictSize) in all versions
            int size = buffer.getShort() & 0xffff;
            if (size != 5)
                throw new UnsupportedOperationException();

            byte propByte = buffer.get();

            // Dictionary size is an unsigned 32-bit little endian integer.
            int dictSize = buffer.getInt();

            long uncompressedSize;
            if ((ze.getRawFlag() & (1 << 1)) != 0)
            {
                // If the entry uses EOS marker, use -1 to indicate
                uncompressedSize = -1;
            } else {
                uncompressedSize = ze.getSize();
            }

            return new LZMAInputStream(inputStream, uncompressedSize, propByte, dictSize);
        } else {
            throw new UnsupportedOperationException();
        }
    }
}