public class

Base64InputStream

extends FilterInputStream
java.lang.Object
   ↳ java.io.InputStream
     ↳ java.io.FilterInputStream
       ↳ org.apache.commons.codec.binary.Base64InputStream

Class Overview

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 Also

Summary

[Expand]
Inherited Fields
From class java.io.FilterInputStream
Public Constructors
Base64InputStream(InputStream in)
Creates a Base64InputStream such that all data read is Base64-decoded from the original provided InputStream.
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.
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.
Public Methods
boolean markSupported()
int read()
Reads one byte from this input stream.
int read(byte[] b, int offset, int len)
Attempts to read len bytes into the specified b array starting at offset from this InputStream.
[Expand]
Inherited Methods
From class java.io.FilterInputStream
From class java.io.InputStream
From class java.lang.Object
From interface java.io.Closeable

Public Constructors

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.

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.

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.

Public Methods

public boolean markSupported ()

Returns
  • false

public int read ()

Reads one byte from this input stream.

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.

public int read (byte[] b, int offset, int len)

Attempts to read len bytes into the specified b array starting at offset from this InputStream.

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