CODEWITHSUNDEEP
javazipunzip
newbie
newbie

Reputation: 24635

How can I read files from Zip file to memory with Java?

I found example from SUN site (http://java.sun.com/developer/technicalArticles/Programming/compression/), but it returns BufferedOutputStream. But I would like to get ZipEntry file as InputStream and then process next file. Is that possible? My program has no access to harddisk, so it cannot even temporarily save files.

import java.io.*;
import java.util.zip.*;

public class UnZip {
   final int BUFFER = 2048;
   public static void main (String argv[]) {
      try {
         BufferedOutputStream dest = null;
         FileInputStream fis = new 
       FileInputStream(argv[0]);
         ZipInputStream zis = new 
       ZipInputStream(new BufferedInputStream(fis));
         ZipEntry entry;
         while((entry = zis.getNextEntry()) != null) {
            System.out.println("Extracting: " +entry);
            int count;
            byte data[] = new byte[BUFFER];
            // write the files to the disk
            FileOutputStream fos = new 
          FileOutputStream(entry.getName());
            dest = new 
              BufferedOutputStream(fos, BUFFER);
            while ((count = zis.read(data, 0, BUFFER)) 
              != -1) {
               dest.write(data, 0, count);
            }
            dest.flush();
            dest.close();
         }
         zis.close();
      } catch(Exception e) {
         e.printStackTrace();
      }
   }
}

Upvotes: 9

Views: 16534

Answers (2)

JakesIV
JakesIV

Reputation: 41

This process reads the whole zip file and just dumps it to a stream, it does not read/split the individual files within the zip. Its sad that the ZIP library does not provide one with the inputstream of each individual file within the ZIP stream.

Upvotes: 0

CodeCaster
CodeCaster

Reputation: 151594

Well, just change the part that writes the file into something you want to do with the data.

while((entry = zis.getNextEntry()) != null) {
    System.out.println("Extracting: " + entry);
    int count;
    byte[] data = new byte[BUFFER];
    String filename = entry.getName();
    System.out.println("Filename: " + filename);
    while ((count = zis.read(data, 0, BUFFER)) != -1) {
       // Do whatever you want with the data variable
       System.out.println(data);
    }
}

Upvotes: 16

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