Package org.apache.kerby.util

Class Base64InputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
org.apache.kerby.util.Base64InputStream
All Implemented Interfaces:
Closeable, AutoCloseable
public class Base64InputStream extends FilterInputStream
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).

Since:
1.4
Version:
$Id: Base64InputStream.java 155 2009-09-17 21:00:58Z julius $
Author:
Apache Software Foundation
See Also:

  • Constructor Details

    • Base64InputStream

      public Base64InputStream(InputStream in)
      Creates a Base64InputStream such that all data read is Base64-decoded from the original provided InputStream.
      Parameters:
      in - InputStream to wrap.

    • Base64InputStream

      public Base64InputStream(InputStream in, boolean doEncode)
      Creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original provided InputStream.
      Parameters:
      in - InputStream to wrap.
      doEncode - true if we should encode all data read from us, false if we should decode.

    • Base64InputStream

      public Base64InputStream(InputStream in, boolean doEncode, int lineLength, byte[] lineSeparator)
      Creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original provided InputStream.
      Parameters:
      in - InputStream to wrap.
      doEncode - true if we should encode all data read from us, false if we should decode.
      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.
      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.

  • Method Details

    • read

      public int read() throws IOException
      Reads one byte from this input stream.
      Overrides:
      read in class FilterInputStream
      Returns:
      the byte as an integer in the range 0 to 255. Returns -1 if EOF has been reached.
      Throws:
      IOException - if an I/O error occurs.

    • read

      public int read(byte[] b, int offset, int len) throws IOException
      Attempts to read len bytes into the specified b array starting at offset from this InputStream.
      Overrides:
      read in class FilterInputStream
      Parameters:
      b - destination byte array
      offset - where to start writing the bytes
      len - maximum number of bytes to read
      Returns:
      number of bytes read
      Throws:
      IOException - if an I/O error occurs.
      NullPointerException - if the byte array parameter is null
      IndexOutOfBoundsException - if offset, len or buffer size are invalid

    • markSupported

      public boolean markSupported()
      Overrides:
      markSupported in class FilterInputStream
      Returns:
      false