Zlib无法在java中提取压缩字符串，压缩是在python中完成的

Question

我试图在java中解压缩字符串，字符串在python中压缩为base64编码。

我试了一天来解决这个问题，这个文件可以很容易地在线解码，也可以用python解码。找到类似的帖子，人们在java和python中压缩和解压缩有困难。

zip.txt

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Base64;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;
public class CompressionUtils {
private static final int BUFFER_SIZE = 1024;
public static byte[] decompress(final byte[] data) {
final Inflater inflater = new Inflater();
inflater.setInput(data);
ByteArrayOutputStream outputStream =
new ByteArrayOutputStream(data.length);
byte[] buffer = new byte[data.length];
try {
while (!inflater.finished()) {
final int count = inflater.inflate(buffer);
outputStream.write(buffer, 0, count);
}
outputStream.close();
} catch (DataFormatException | IOException e) {
e.printStackTrace();
log.error("ZlibCompression decompress exception: {}", e.getMessage());
}
inflater.end();
return outputStream.toByteArray();
}
public static void main(String[] args) throws IOException {
decompress(Base64.getDecoder().decode(Files.readAllBytes(Path.of("zip.txt"))));
}
}

错误:

java.util.zip.DataFormatException: incorrect header check
at java.base/java.util.zip.Inflater.inflateBytesBytes(Native Method)
at java.base/java.util.zip.Inflater.inflate(Inflater.java:378)
at java.base/java.util.zip.Inflater.inflate(Inflater.java:464) 

在@Mark Adler的建议之后也尝试了这个

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

byte[] decoded = Base64.getDecoder().decode(Files.readAllBytes(Path.of("zip.txt")));
ByteArrayInputStream in = new ByteArrayInputStream(decoded);
GZIPInputStream gzStream = new GZIPInputStream(in);
decompress(gzStream.readAllBytes());
gzStream.close();
}
java.util.zip.DataFormatException: incorrect header check
at java.base/java.util.zip.Inflater.inflateBytesBytes(Native Method)
at java.base/java.util.zip.Inflater.inflate(Inflater.java:378)
at java.base/java.util.zip.Inflater.inflate(Inflater.java:464)
at efrisapi/com.efrisapi.util.CompressionUtils.decompress(CompressionUtils.java:51)
at efrisapi/com.efrisapi.util.CompressionUtils.main(CompressionUtils.java:67)

Answer 1

这是一个gzip流，而不是zlib流。使用GZIPInputStream

Answer 2

我看错方向了，字符串被压缩了，下面是解析它的代码。谢谢你@Mark Adler用于识别问题。

public static void deCompressGZipFile(String gZippedFile, String newFile) throws IOException {
byte[] decoded = Base64.getDecoder().decode(Files.readAllBytes(Path.of(gZippedFile)));
ByteArrayInputStream in = new ByteArrayInputStream(decoded);
GZIPInputStream gZIPInputStream = new GZIPInputStream(in);
FileOutputStream fos = new FileOutputStream(newFile);
byte[] buffer = new byte[1024];
int len;
while ((len = gZIPInputStream.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
// Keep it in finally
fos.close();
gZIPInputStream.close();
}