(Android™) Remove an Entry from an Existing ZIP Using DeleteEntry

This example demonstrates how to use the DeleteEntry method to remove a file from an existing ZIP archive.

The example:

• Creates a ZIP archive containing three text files
• Opens the ZIP archive for modification
• Finds and deletes one entry
• Writes the modified ZIP archive to a new filename

Suppose the original ZIP archive contains:

a.txt
b.txt
c.txt

After deleting b.txt, the modified ZIP archive contains:

a.txt
c.txt

The entry is removed only from the in-memory ZIP object until a Write* method is called.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ 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 {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    success = false;

    // ------------------------------------------------------------
    // First create a ZIP archive containing three text files.

    CkZip zip = new CkZip();

    success = zip.NewZip("original.zip");
    if (success == false) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    String charset = "utf-8";

    success = zip.AddString("a.txt","Contents of file A",charset);
    if (success == false) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    success = zip.AddString("b.txt","Contents of file B",charset);
    if (success == false) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    success = zip.AddString("c.txt","Contents of file C",charset);
    if (success == false) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    // Write the ZIP archive to disk.
    // 
    // The ZIP now contains:
    // 
    //     a.txt
    //     b.txt
    //     c.txt
    // 
    success = zip.WriteZipAndClose();
    if (success == false) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    // ------------------------------------------------------------
    // Open the existing ZIP archive for modification.

    CkZip zip2 = new CkZip();

    success = zip2.OpenZip("original.zip");
    if (success == false) {
        Log.i(TAG, zip2.lastErrorText());
        return;
        }

    // Find the entry named "b.txt".
    CkZipEntry entry = new CkZipEntry();

    success = zip2.EntryOf("b.txt",entry);
    if (success == false) {
        Log.i(TAG, zip2.lastErrorText());
        return;
        }

    // Remove the entry from the in-memory ZIP object.
    // 
    // At this point, the original ZIP file on disk is unchanged.
    // The deletion takes effect only after WriteZip or
    // WriteZipAndClose is called.
    success = zip2.DeleteEntry(entry);
    if (success == false) {
        Log.i(TAG, zip2.lastErrorText());
        return;
        }

    // Write the modified ZIP archive to a new file.
    zip2.put_FileName("modified.zip");

    success = zip2.WriteZipAndClose();
    if (success == false) {
        Log.i(TAG, zip2.lastErrorText());
        return;
        }

    // The modified ZIP now contains:
    // 
    //     a.txt
    //     c.txt
    // 

    Log.i(TAG, "ZIP archive updated successfully.");

  }

  static {
      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."
  }
}