pad and unpad byte array

Demonstrates using the pad and unpad methods of CkByteArray.

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[])
  {

    byte[] data_bytes = { (byte)0, (byte)1, (byte)2, (byte)3, (byte)4, (byte)5, (byte)6, (byte)7, (byte)8, (byte)9};
    CkByteData data = new CkByteData();
    data.appendByteArray(data_bytes);

    //  These are the padding options for the "pad" method:
    //  0 = Each padding byte is the pad count (16 extra added if size is already a multiple of 16)
    //  1 = Random bytes except the last is the pad count (16 extra added if size is already multiple of 16)
    //  2 = Pad with random data. (If already a multiple of 16, no padding is added).
    //  3 = Pad with NULLs. (If already a multiple of 16, no padding is added).
    //  4 = Pad with SPACE chars(0x20). (If already a multiple of 16, no padding is added).

    //  We'll pad to a block size of 16 bytes.
    int blockSize;
    blockSize = (int) 16;

    int paddingScheme;
    paddingScheme = (int) 0;

    //  Pad, display the padded byte data, unpad, then re-display
    data.pad(blockSize,paddingScheme);
    System.out.println(data.getEncoded("hex"));
    data.unpad(16,paddingScheme);
    System.out.println(data.getEncoded("hex"));
    System.out.println("----");

    paddingScheme = (int) 1;
    //  Pad, display the padded byte data, unpad, then re-display
    data.pad(blockSize,paddingScheme);
    System.out.println(data.getEncoded("hex"));
    data.unpad(16,paddingScheme);
    System.out.println(data.getEncoded("hex"));
    System.out.println("----");

    //  There is no unpadding with schemes 2,3, and 4
    byte[] data2_bytes = { (byte)0, (byte)1, (byte)2, (byte)3, (byte)4, (byte)5, (byte)6, (byte)7, (byte)8, (byte)9};
    CkByteData data2 = new CkByteData();
    data2.appendByteArray(data2_bytes);
    paddingScheme = (int) 2;
    //  Pad and display the padded byte data
    data2.pad(blockSize,paddingScheme);
    System.out.println(data2.getEncoded("hex"));
    System.out.println("----");

    //  There is no unpadding with schemes 2,3, and 4
    byte[] data3_bytes = { (byte)0, (byte)1, (byte)2, (byte)3, (byte)4, (byte)5, (byte)6, (byte)7, (byte)8, (byte)9};
    CkByteData data3 = new CkByteData();
    data3.appendByteArray(data3_bytes);
    paddingScheme = (int) 3;
    //  Pad and display the padded byte data
    data3.pad(blockSize,paddingScheme);
    System.out.println(data3.getEncoded("hex"));
    System.out.println("----");

    //  There is no unpadding with schemes 2,3, and 4
    byte[] data4_bytes = { (byte)0, (byte)1, (byte)2, (byte)3, (byte)4, (byte)5, (byte)6, (byte)7, (byte)8, (byte)9};
    CkByteData data4 = new CkByteData();
    data4.appendByteArray(data4_bytes);
    paddingScheme = (int) 4;
    //  Pad and display the padded byte data
    data4.pad(blockSize,paddingScheme);
    System.out.println(data4.getEncoded("hex"));
    System.out.println("----");
  }
}