Append In-Memory Data to Existing Zip w/out Rewriting Entire Zip

Demonstrates how to use the QuickAppend method to append in-memory data (string or byte array) 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 or data 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 Java Library

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    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) {
        System.out.println(zip.lastErrorText());
        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) {
        System.out.println(zip.lastErrorText());
        return;
    }

    String inZipFilename;
    String strData;
    String strCharset;
    inZipFilename = "something.txt";
    strData = "abcdefghijklmnopqrstuvwxyz1234567890";
    strCharset = "iso-8859-1";
    //  Append a string as a file to the existing zip object.
    //  Please read the notes about strCharset below.
    zip.AppendString2(inZipFilename,strData,strCharset);

    //  Note: The AppendString method is identical to AppendString2,
    //  except the strCharset argument is omitted and it is assumed
    //  you desire the ANSI charset.

    //  Note: You may append a byte array (or Variant containing
    //  a byte array for ActiveX users) by calling AppendData.

    //  Appends the contents of this 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) {
        System.out.println(zip.lastErrorText());
        return;
    }

    System.out.println("Success!");

    //  Note about strCharset:
    //  string variables in many programming language are Unicode.
    //  It is likely that you don't want to create .zip that contains
    //  a text file that will unzip to Unicode characters (2 bytes/char).
    //  The strCharset argument allows you to specify the exact
    //  charset to use.  When the string is added to the .zip, it
    //  is first converted to this charset.  English strings
    //  may use "us-ascii".  Western-European languages typically
    //  use "iso-8859-1" or "windows-1252".  Japanese might choose
    //  between "shift_jis", "iso-2022-jp", "euc-jp", etc.
    //  Chilkat supports all major character encodings.
    //  You may always use "ansi" or "utf-8".

    //  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.

  }
}