Read ZipInputStream in Kotlin

Question

I am trying to read a zipped file using Kotlin and ZipInputStream into a ByteArrayOutputStream()

val f = File("/path/to/zip/myFile.zip")
val zis = ZipInputStream(FileInputStream(f))

//loop through all entries in the zipped file
var entry = zis.nextEntry
while(entry != null) {
    val baos = ByteArrayOutputStream()

    //read the entry into a ByteArrayOutputStream
    zis.use{ it.copyTo(baos) }

    val bytes = baos.toByteArray()

    System.out.println(bytes[0])

    zis.closeEntry()  //error thrown here on first iteration
    entry = zis.nextEntry
}

The error I get is:

java.io.IOException: Stream closed
    at java.util.zip.ZipInputStream.ensureOpen(ZipInputStream.java:67)
    at java.util.zip.ZipInputStream.closeEntry(ZipInputStream.java:139)
    <the code above>

I thought maybe zis.use is closing the entry already after the contents of the entry are read, so I removed zis.closeEntry(), but then it produced the same error when trying to get the next entry

I know zis.use is safe and guarantees the input stream is closed, but I would expect it to close just the entry if anything rather than the entire stream.

Having printed the entire byte array, I know only the first file in the zip is being read during zis.use

Is there a good way to read all entries in a ZipInputStream in kotlin?

Answer 1

The use function calls the close() method, which closes the entire stream, rather than closeEntry(), which closes just the current entry. I think you should wrap your entire while loop with zis.use { ... }, rather than calling it for each entry.