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Java

Encrypt Already Existing Zip

See more Zip Examples

To encrypt an already existing non-encrypted .zip, the application must open the .zip, set the encryption related properties, and then re-write.

Chilkat Java Downloads

Chilkat2 Java
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Zip;

public class ChilkatExample {

    public static void main(String[] args) {
        // This requires the Chilkat Zip API to have been previously unlocked.
        // See Unlock Chilkat Zip for sample code.

        Zip zip = new Zip();

        // Open an unencrypted .zip
        try {
            zip.openZip("qa_data/zips/test.zip");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Unzip to a temp directory.
        int numFilesUnzipped = zip.unzip("qa_output/tmp");
        if (numFilesUnzipped < 0) {
            System.out.println(zip.getLastErrorText());
            return;
        }

        // Clear the zip object.
        zip.newZip("qa_output/aesTest.zip");

        // Indicate that 128-bit AES encryption is to be used when writing the .zip
        zip.setEncryption(4);
        zip.setEncryptKeyLength(128);

        // Set the password.
        zip.setEncryptPassword("secret");

        // Append the files.
        zip.setAppendFromDir("qa_output/tmp");
        try {
            zip.appendFiles("*.*", true);

            // Write the .zip and close it.
            zip.writeZipAndClose();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

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