panda.codec.binary.Base64InputStream Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of panda-core Show documentation

Panda Core is the core module of Panda Framework, it contains commonly used utility classes similar to apache-commons.

There is a newer version: 1.8.0

package panda.codec.binary;

import java.io.InputStream;

/**
 * Provides Base64 encoding and decoding in a streaming fashion (unlimited size). When encoding the default lineLength
 * is 76 characters and the default lineEnding is CRLF, but these can be overridden by using the appropriate
 * constructor.
 * 
 * The default behaviour of the Base64InputStream is to DECODE, whereas the default behaviour of the Base64OutputStream
 * is to ENCODE, but this behaviour can be overridden by using a different constructor.
 * 
 * 
 * This class implements section 6.8. Base64 Content-Transfer-Encoding from RFC 2045 Multipurpose
 * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies by Freed and Borenstein.
 * 
 * 
 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode
 * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
 * 
 *
 * @see RFC 2045
 * 
 */
public class Base64InputStream extends BaseNCodecInputStream {

	/**
	 * Creates a Base64InputStream such that all data read is Base64-decoded from the original
	 * provided InputStream.
	 * 
	 * @param in InputStream to wrap.
	 */
	public Base64InputStream(final InputStream in) {
		this(in, false);
	}

	/**
	 * Creates a Base64InputStream such that all data read is either Base64-encoded or
	 * Base64-decoded from the original provided InputStream.
	 * 
	 * @param in InputStream to wrap.
	 * @param doEncode true if we should encode all data read from us, false if we should decode.
	 */
	public Base64InputStream(final InputStream in, final boolean doEncode) {
		super(in, new Base64(false), doEncode);
	}

	/**
	 * Creates a Base64InputStream such that all data read is either Base64-encoded or
	 * Base64-decoded from the original provided InputStream.
	 * 
	 * @param in InputStream to wrap.
	 * @param doEncode true if we should encode all data read from us, false if we should decode.
	 * @param lineLength If doEncode is true, each line of encoded data will contain lineLength
	 *            characters (rounded down to nearest multiple of 4). If lineLength <=0, the encoded
	 *            data is not divided into lines. If doEncode is false, lineLength is ignored.
	 * @param lineSeparator If doEncode is true, each line of encoded data will be terminated with
	 *            this byte sequence (e.g. \r\n). If lineLength <= 0, the lineSeparator is not used.
	 *            If doEncode is false lineSeparator is ignored.
	 */
	public Base64InputStream(final InputStream in, final boolean doEncode, final int lineLength,
			final byte[] lineSeparator) {
		super(in, new Base64(lineLength, lineSeparator), doEncode);
	}
}