CODEWITHSUNDEEP
javazipphp-ziparchive
Catalin Vladu
Catalin Vladu

Reputation: 389

Open an archive file which is in another archive file using Java

I have a file named "file.ear". This file contains several files, including a "war" file, named "file.war" (which is also an archive). I intend to open a text file which is in "file.war". In this moment, my question is which is the best way to create a ZipFile object from this "file.war"

I created a ZipFile object from "file.ear" and iterated the entries. When the entry is "file.war" I tried to create another ZipFile

ZipFile earFile = new ZipFile("file.ear");
Enumeration(? extends ZipEntry) earEntries = earFile.entries();

while (earEntries.hasMoreElements()) {
    ZipEntry earEntry = earEntries.nextElement();
    if (earEntry.toString().equals("file.war")) {
        // in this line I want to get a ZipFile from the file "file.war"
        ZipFile warFile = new ZipFile(earEntry.toString());
    }
}

I expect to get a ZipFile instance from "file.war" and the line marked throws a FileNotFoundException.

Upvotes: 0

Views: 893

Answers (1)

Highbrainer
Highbrainer

Reputation: 760

ZipFile is only for ... files. A ZipEntry is only in memory, not on the harddrive.

You're better off using ZipInputStream :

  1. you wrap your FileInputStream into a ZipInputStream
  2. you get a hold onto the .war entry's InputStream
  3. you wrap the .war in turn InputStreaminto a ZipInputStream
  4. you can get a hold on the text file entry, read its InputStream
  5. do whatever you want with the text InputStream!
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Scanner;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class Snippet {

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

        InputStream w = getInputStreamForEntry(new FileInputStream("file.ear"), "file.war");
        InputStream t = getInputStreamForEntry(w, "prova.txt");

        try (Scanner s = new Scanner(t);) {
            s.useDelimiter("\\Z+");
            if (s.hasNext()) {
                System.out.println(s.next());
            }
        }

    }

    protected static InputStream getInputStreamForEntry(InputStream in, String entry)
            throws FileNotFoundException, IOException {
        ZipInputStream zis = new ZipInputStream(in);

        ZipEntry zipEntry = zis.getNextEntry();

        while (zipEntry != null) {
            if (zipEntry.toString().equals(entry)) {
                // in this line I want to get a ZipFile from the file "file.war"
                return zis;
            }
            zipEntry = zis.getNextEntry();
        }
        throw new IllegalStateException("No entry '" + entry + "' found in zip");
    }

}

HTH!

Upvotes: 1

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