CSV 压缩后填充更改为字节数组

Question

so i receive a CSV file from front end and i need to compress it and store it into MySql DB. The problem is that after i decompress the file back it is altered and is not having a CSV structure anymore (I compress using ZIP but I have also tried gzip). For example this is the file before compression

header1,header2,header3,header4,header5
val,val2,val3,val4,val5
val6,val7,val8,val9,val10

And this is the file after decompression

header1,header2,header3,header4,header5val1,val2,val3,val4,val5val6,val7,val8.val9.val10

I need to send the decompressed file to a python time series analysis service and it cannot parse it properly.

I compress/decompress the file directly as a byteArray and i am sure the compression is the problem because i have tried to store and fetch an uncompressed CSV and it works fine. Thanks in advance!

Here is the code used for compression

@Throws(Exception::class)
fun compressFile(file : ByteArray) : ByteArray {
   val baos = ByteArrayOutputStream()
   val zos = ZipOutputStream(baos)
   val entry = ZipEntry("data.csv")
   entry.size = file.size.toLong()
   zos.putNextEntry(entry)
   zos.write(file)
   zos.closeEntry()
   zos.close()
   return baos.toByteArray()
}

And here is the code used for decompression

@Throws(Exception::class)
fun decompressFile(file : ByteArray): ByteArray {
   if (file.isEmpty()) return file
   val gis = ZipInputStream(ByteArrayInputStream(file))
   gis.nextEntry
   val bf = BufferedReader(InputStreamReader(gis, "UTF-8"))
   var outStr = ""
   var line: String
   while (bf.readLine().also { line = it ?: "" } != null) {
       outStr += line
   }
   gis.close()
   bf.close()
   return outStr.toByteArray()
}

Answer 1

I think, you lose your NL character, because BufferedReader.readLine() reads ONLY the line without the new line at the end. That is, you concat Line1Line2, but skips the new line between them.

You should not read the stream through bufferedreader, you need to read the ENTIRE content, including the new line characters, see https://www.baeldung.com/convert-input-stream-to-string