Posted by: iBNuX | April 22, 2010

Base64CoderUtil

public class Base64CoderUtil {
	//	Dummy constructor.
	 private Base64CoderUtil() {
	 }

	 // Mapping table from 6-bit nibbles to Base64 characters.
	private static char[] map1 = new char[64];
	static {
		int i = 0;
		for (char c = 'A'; c < = 'Z'; c++)
			map1[i++] = c;
		for (char c = 'a'; c <= 'z'; c++)
			map1[i++] = c;
		for (char c = '0'; c <= '9'; c++)
			map1[i++] = c;
		map1[i++] = '+';
		map1[i++] = '/';
	}

	// Mapping table from Base64 characters to 6-bit nibbles.
	private static byte[] map2 = new byte[128];
	static {
		for (int i = 0; i < map2.length; i++)
			map2[i] = -1;
		for (int i = 0; i < 64; i++)
			map2[map1[i]] = (byte) i;
	}

	/**
	 * @Purpose:Encodes a string into Base64 format. No blanks or line breaks are
	 * inserted.
	 * @param String to be encoded.
	 * @return A String with the Base64 encoded data.
	 */
	public static String encodeString(String plainTxtString) {
		return new String(encode(plainTxtString.getBytes()));
	}

	/**
	 * @Purpose:Encodes a byte array into Base64 format. No blanks or line breaks are
	 * inserted.
	 * @param in an array containing the data bytes to be encoded.
	 * @return A character array with the Base64 encoded data.
	 */
	private static char[] encode(byte[] in) {
		return encode(in, in.length);
	}

	/**
	 * @Purpose:Encodes a byte array into Base64 format. No blanks or line breaks are
	 * inserted.
	 * @param in an array containing the data bytes to be encoded.
	 * @param iLennumber of bytes to process in in.
	 * @return A character array with the Base64 encoded data.
	 */
	private static char[] encode(byte[] in, int iLen) {
		int oDataLen = (iLen * 4 + 2) / 3; // output length without padding
		int oLen = ((iLen + 2) / 3) * 4; // output length including padding
		char[] out = new char[oLen];
		int ip = 0;
		int op = 0;
		while (ip < iLen) {
			int i0 = in[ip++] & 0xff;
			int i1 = ip < iLen ? in[ip++] & 0xff : 0;
			int i2 = ip >> 2;
			int o1 = ((i0 & 3) < >> 4);
			int o2 = ((i1 & 0xf) < >> 6);
			int o3 = i2 & 0x3F;
			out[op++] = map1[o0];
			out[op++] = map1[o1];
			out[op] = op < oDataLen ? map1[o2] : '=';
			op++;
			out[op] = op  0 && in[iLen - 1] == '=')
			iLen--;
		int oLen = (iLen * 3) / 4;
		byte[] out = new byte[oLen];
		int ip = 0;
		int op = 0;
		while (ip < iLen) {
			int i0 = in[ip++];
			int i1 = in[ip++];
			int i2 = ip < iLen ? in[ip++] : 'A';
			int i3 = ip  127 || i1 > 127 || i2 > 127 || i3 > 127)
				throw new IllegalArgumentException(
						"Illegal character in Base64 encoded data.");
			int b0 = map2[i0];
			int b1 = map2[i1];
			int b2 = map2[i2];
			int b3 = map2[i3];
			if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0)
				throw new IllegalArgumentException(
						"Illegal character in Base64 encoded data.");
			int o0 = (b0 <>> 4);
			int o1 = ((b1 & 0xf) < >> 2);
			int o2 = ((b2 & 3) < < 6) | b3;
			out[op++] = (byte) o0;
			if (op < oLen)
				out[op++] = (byte) o1;
			if (op < oLen)
				out[op++] = (byte) o2;
		}
		return out;
	}
} // end class Base64CoderUtil 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories