CODEWITHSUNDEEP
javacollectionscollision-detection
Dwarakanathareddy
Dwarakanathareddy

Reputation: 51

throw an exception "duplicate entry" java.util.zip.ZipException

I have a program which downloads a bunch of documents from a remote server and after, bundles them up in a .zip file using ZipOutputStream.

The problem is that when I download the files, there could be more than one file with the same file name. So, when I try to put an entry with the same file name which is in already ZipOutputStream, it will throw an exception "duplicate entry".

Is there a way, I can check for duplicate entry, before adding the zip entry to ZipOutputStream? so I can rename the duplicate file?

Please advise...

Upvotes: 1

Views: 4971

Answers (2)

Xavi López
Xavi López

Reputation: 27880

You could achieve that by adding each filename you add to an efficient data structure such as a HashSet and check if the name is already there. The add method, which returns true if the element was not already in the Set, and false otherwise.

Set<String> addedNames = new HashSet<String>();
// Start processing of the file set
for (String fileName : fileNames) { 
     if (addedNames.add(fileName) { 
          // Process file
     }
     else { 
         throw new DuplicateException(fileName);
     } 
}

Upvotes: 1

Logar
Logar

Reputation: 1248

Why not registering all of your filenames in a sorted array/map/hash, and check all of them before adding your new file ?

Upvotes: 1

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