CODEWITHSUNDEEP
groovy
aldrin
aldrin

Reputation: 4572

Why does `readLines` close a ZipInputStream?

In Groovy (v2.4.1), I'm trying to read the contents of the files within a zipped file,

import java.util.zip.*

ZipInputStream zis = new ZipInputStream(new FileInputStream("d:\\temp\\small.zip"))

while (zipEntry = zis.nextEntry) {
    println "Reading ${zipEntry.name}..."
    def filedata = zis.readLines()
    println filedata
}

gives the following error after reading the first file in the zip,

java.io.IOException: Stream closed

Why does that happen? It is same with eachLine and getText too ( haven't tried any other methods in InputStream) How can I read all the zip file contents from a ZipInputStream in groovy?

Update: Though I've used a file as an example above, I actually only have an InputStream and not a physical file

Upvotes: 1

Views: 813

Answers (1)

Opal
Opal

Reputation: 84784

InputStream's readLines() method is added via this class. When you look at line no 791 you will see that readLines() is delegated to the overridden version with Reader as an argument. As it can be seen in the docs this method closes the stream after reading it. That's why the your example fails.

Here's how it can be done:

import java.util.zip.*

def zis = new ZipInputStream(new FileInputStream('lol.zip'))

while (zipEntry = zis.nextEntry) {
    println "Reading $zipEntry.name"
    def output = new ByteArrayOutputStream()
    output << zis
    println "Output: $output"
}

Upvotes: 4

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