(Chilkat for Android™ API)
Append Files to Existing Zip w/out Rewriting Entire Zip

Demonstrates how to use the QuickAppend method to append files to an existing .zip archive. This method works by editing the existing .zip -- it does not rewrite or recompress the contents of the existing .zip. It is the fastest way to append additional files to a pre-existing large .zip archive. Note: The QuickAppend method is new and available in the pre-release downloads, or in official releases dated after 6-October-2007.

Download: Chilkat for Android™ Java Libraries

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {
  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    TextView tv = new TextView(this);
    String outStr = "";

    CkZip zip = new CkZip();

    boolean success;

    //  Any string unlocks the component for the 1st 30-days.
    success = zip.UnlockComponent("Anything for 30-day trial");
    if (success != true) {
        outStr += zip.lastErrorText() + "\n";
        tv.setText(outStr);
        setContentView(tv);
        return;
    }

    //  The NewZip method only initializes the Zip object -- it does
    //  not create or write a .zip file.
    success = zip.NewZip("notUsed.zip");
    if (success != true) {
        outStr += zip.lastErrorText() + "\n";
        tv.setText(outStr);
        setContentView(tv);
        return;
    }

    //  Add a reference to a file.  This is the file that will
    //  be added to a pre-existing .zip archive.
    //  Note: this does not read or compress the file contents --
    //  it simply adds a reference to the zip object.
    boolean saveExtraPath;
    saveExtraPath = false;
    success = zip.AppendOneFileOrDir("something.dat",saveExtraPath);
    if (success != true) {
        outStr += zip.lastErrorText() + "\n";
        tv.setText(outStr);
        setContentView(tv);
        return;
    }

    //  Appends the contents of the zip object to the preExisting.zip
    //  zip archive.  preExisting.zip is opened, and the files
    //  referenced by this zip object are streamed in, compressed,
    //  and appended to the end of the archive.
    success = zip.QuickAppend("preExisting.zip");
    if (success != true) {
        outStr += zip.lastErrorText() + "\n";
        tv.setText(outStr);
        setContentView(tv);
        return;
    }

    outStr += "Success!" + "\n";

    //  Note: Additional files, directory trees, or in-memory data
    //  can be appended by calling AppendOneFileOrDir, AppendFiles,
    //  AppendString, AppendData, etc. multiple times.
    //  Whatever files and/or in-memory data that are referenced by
    //  this zip object will be appended to preExisting.zip when
    //  QuickAppend is called.

    tv.setText(outStr);
    setContentView(tv);
  }

  static {
      // Important: Make sure the name passed to loadLibrary matches the shared library
      // found in your project's libs/armeabi directory.
      //  for "libchilkat.so", pass "chilkat" to loadLibrary
      //  for "libchilkatemail.so", pass "chilkatemail" to loadLibrary
      //  etc.
      // 
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}