public Base64Encoder(String input) 
{
		byte bytes[];
		try
		{
			bytes = input.getBytes("ISO-8859-1");
		}
		catch (UnsupportedEncodingException ex)
		{
			throw new RuntimeException(
				this.getClass().getName()
					+ "[Constructor] Unable to convert"
					+ "properly char to bytes");
		}
		this.stringp = true;
		this.in = new ByteArrayInputStream(bytes);
		this.out = new ByteArrayOutputStream();
}

Create a new Base64 encoder, to encode the given string.

Parameters:

input - The String to be encoded.

 public Base64Encoder(InputStream in,
    OutputStream out) 
{
		this.in = in;
		this.out = out;
		this.stringp = false;
}

Create a new Base64 encoder, encoding input to output.

Parameters:

in - The input stream to be encoded.

out - The output stream, to write encoded data to.

 public static  void main(String[] args) 
{
		if (args.length != 1)
		{
			System.out.println("Base64Encoder < string >");
			System.exit(0);
		}
		Base64Encoder b = new Base64Encoder(args[0]);
		System.out.println("[" + b.processString() + "]");
		// joe:eoj - > am9lOmVvag==
		// 12345678:87654321 - > MTIzNDU2Nzg6ODc2NTQzMjE=
}

Testing the encoder. Run with one argument, prints the encoded version of it.

 public  void process() throws IOException 
{
		byte buffer[] = new byte[BUFFER_SIZE];
		int got = -1;
		int off = 0;
		int count = 0;
		while ((got = in.read(buffer, off, BUFFER_SIZE - off))  > 0)
		{
			if (got  >= 3)
			{
				got += off;
				off = 0;
				while (off + 3 < = got)
				{
					int c1 = get1(buffer, off);
					int c2 = get2(buffer, off);
					int c3 = get3(buffer, off);
					int c4 = get4(buffer, off);
					switch (count)
					{
						case 73 :
							out.write(encoding[c1]);
							out.write(encoding[c2]);
							out.write(encoding[c3]);
							out.write('\n");
							out.write(encoding[c4]);
							count = 1;
							break;
						case 74 :
							out.write(encoding[c1]);
							out.write(encoding[c2]);
							out.write('\n");
							out.write(encoding[c3]);
							out.write(encoding[c4]);
							count = 2;
							break;
						case 75 :
							out.write(encoding[c1]);
							out.write('\n");
							out.write(encoding[c2]);
							out.write(encoding[c3]);
							out.write(encoding[c4]);
							count = 3;
							break;
						case 76 :
							out.write('\n");
							out.write(encoding[c1]);
							out.write(encoding[c2]);
							out.write(encoding[c3]);
							out.write(encoding[c4]);
							count = 4;
							break;
						default :
							out.write(encoding[c1]);
							out.write(encoding[c2]);
							out.write(encoding[c3]);
							out.write(encoding[c4]);
							count += 4;
							break;
					}
					off += 3;
				}
				// Copy remaining bytes to beginning of buffer:
				for (int i = 0; i <  3; i++)
					buffer[i] = (i <  got - off) ? buffer[off + i] : ((byte) 0);
				off = got - off;
			}
			else
			{
				// Total read amount is less then 3 bytes:
				off += got;
			}
		}
		// Manage the last bytes, from 0 to off:
		switch (off)
		{
			case 1 :
				out.write(encoding[get1(buffer, 0)]);
				out.write(encoding[get2(buffer, 0)]);
				out.write('=");
				out.write('=");
				break;
			case 2 :
				out.write(encoding[get1(buffer, 0)]);
				out.write(encoding[get2(buffer, 0)]);
				out.write(encoding[get3(buffer, 0)]);
				out.write('=");
		}
		return;
}

Process the data: encode the input stream to the output stream. This method runs through the input stream, encoding it to the output stream.

 public String processString() 
{
		if (!stringp)
			throw new RuntimeException(
				this.getClass().getName()
					+ "[processString]"
					+ "invalid call (not a String)");
		try
		{
			process();
		}
		catch (IOException e)
		{
		}
		return ((ByteArrayOutputStream) out).toString();
}

Encode the content of this encoder, as a string. This methods encode the String content, that was provided at creation time, following the BASE64 rules, as specified in the rfc1521.