(Java) Get Compressed ZIP Entry Data as Base64 Using ZipEntry.CopyToBase64

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This example creates a small ZIP archive containing a text file added from memory, writes the ZIP to disk, re-opens it, and then uses ZipEntry.CopyToBase64 to retrieve the compressed data for the text file as a Base64-encoded string.

The Base64 string returned by CopyToBase64 represents the compressed bytes stored for the entry inside the ZIP archive. It is not the original uncompressed text data.

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

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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;

    // ------------------------------------------------------------
    // First create a sample ZIP archive containing a small text file.

    CkZip zip = new CkZip();

    success = zip.NewZip("c:/temp/sampleText.zip");
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

    // Add a small text file from memory.
    // The text is stored in the ZIP as "hello.txt".
    success = zip.AddString("hello.txt","Hello from a ZIP entry!","utf-8");
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

    // Write the ZIP archive to disk and close it.
    success = zip.WriteZipAndClose();
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

    // ------------------------------------------------------------
    // Now open the ZIP archive we just created.

    CkZip zip2 = new CkZip();

    success = zip2.OpenZip("c:/temp/sampleText.zip");
    if (success == false) {
        System.out.println(zip2.lastErrorText());
        return;
        }

    // Get the text file entry.
    CkZipEntry entry = new CkZipEntry();

    success = zip2.EntryOf("hello.txt",entry);

    if (success == false) {
        System.out.println("Entry not found.");
        return;
        }

    // Get the compressed ZIP entry data as Base64.
    // 
    // This is the compressed data stored inside the ZIP file,
    // not the uncompressed text "Hello from a ZIP entry!".
    String b64 = entry.copyToBase64();

    System.out.println("Base64 compressed ZIP entry data:");
    System.out.println(b64);

    zip2.CloseZip();

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