Unzipping Files with Android (Programmatically)

I wrote an article a few months ago, which walked you through the process of zipping files programmatically with Java - in an Android environment. Due to popular demand, I've decided to write up another article on how to unzip files.

The process is pretty similar, and you could probably combine them both in a single class, but for this example, I made a class called Decompress.

import android.util.Log;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

/**
 *
 * @author jon
 */
public class Decompress {
  private String _zipFile;
  private String _location;

  public Decompress(String zipFile, String location) {
    _zipFile = zipFile;
    _location = location;

    _dirChecker("");
  }

  public void unzip() {
    try  {
      FileInputStream fin = new FileInputStream(_zipFile);
      ZipInputStream zin = new ZipInputStream(fin);
      ZipEntry ze = null;
      while ((ze = zin.getNextEntry()) != null) {
        Log.v("Decompress", "Unzipping " + ze.getName());

        if(ze.isDirectory()) {
          _dirChecker(ze.getName());
        } else {
          FileOutputStream fout = new FileOutputStream(_location + ze.getName());
          for (int c = zin.read(); c != -1; c = zin.read()) {
            fout.write(c);
          }

          zin.closeEntry();
          fout.close();
        }
        
      }
      zin.close();
    } catch(Exception e) {
      Log.e("Decompress", "unzip", e);
    }

  }

  private void _dirChecker(String dir) {
    File f = new File(_location + dir);

    if(!f.isDirectory()) {
      f.mkdirs();
    }
  }
}

Well, that's the class - tested on my Nexus One and works!

Here's an example of how to use it:

String zipFile = Environment.getExternalStorageDirectory() + "/files.zip";
String unzipLocation = Environment.getExternalStorageDirectory() + "/unzipped/";

Decompress d = new Decompress(zipFile, unzipLocation);
d.unzip();

That should unzip files.zip and put the contents into /sdcard/unzipped/, as was specified.

Check out my other article, if you want to find out how to zip files - Zipping Files with Android (Programmatically)