Java

Find a ZIP Entry by EntryID Using EntryById

See more Zip Examples

This example demonstrates how to use the EntryById method to retrieve a ZIP entry using its unique EntryID.

Each ZipEntry object has an EntryID property that uniquely identifies the entry within the currently open ZIP object.

This is useful when:

• An application stores EntryID values for later use
• ZIP entries need to be retrieved without searching by filename
• Multiple entries may have similar names or paths

The example:

• Opens a ZIP archive
• Retrieves an entry using EntryAt
• Saves the entry's EntryID
• Uses EntryById to retrieve the same entry later

Java

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[])
  {
    boolean success = false;

    //  Open an existing ZIP archive.
    CkZip zip = new CkZip();

    success = zip.OpenZip("example.zip");
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

    //  Retrieve the first entry in the ZIP archive.
    CkZipEntry entry = new CkZipEntry();

    success = zip.EntryAt(0,entry);
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

    System.out.println("Original entry:");
    System.out.println("  FileName: " + entry.fileName());
    System.out.println("  EntryID: " + entry.get_EntryID());
    System.out.println("");

    //  Save the EntryID for later use.
    int entryId = entry.get_EntryID();

    //  Create another ZipEntry object.
    CkZipEntry entry2 = new CkZipEntry();

    //  Retrieve the same entry using EntryById.
    success = zip.EntryById(entryId,entry2);
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

    System.out.println("Entry retrieved by EntryID:");
    System.out.println("  FileName: " + entry2.fileName());
    System.out.println("  EntryID: " + entry2.get_EntryID());
    System.out.println("");

    //  The filenames and EntryID values should match.
    zip.CloseZip();

    System.out.println("Done.");
  }
}