Package javax.crypto

Class CipherOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

javax.crypto.CipherOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class CipherOutputStream
extends FilterOutputStream

This class wraps an output stream and a cipher so that write methods send the data through the cipher before writing them to the underlying output stream.

The cipher must be initialized for the requested operation before being used by a CipherOutputStream. For example, if a cipher initialized for encryption is used with a CipherOutputStream, the CipherOutputStream tries to encrypt the data writing it out.

Field Summary

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CipherOutputStream(OutputStream os)	Creates a new CipherOutputStream instance for an OutputStream without a cipher.
	CipherOutputStream(OutputStream os, Cipher c)	Creates a new CipherOutputStream instance for an OutputStream and a Cipher.

Method Summary

Modifier and Type	Method	Description
void	close()	Close this cipher output stream.
void	flush()	Flushes this cipher output stream.
void	write(byte[] b, int off, int len)	Writes the len bytes from buffer b starting at offset off to this cipher output stream.
void	write(int b)	Writes the single byte to this cipher output stream.

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CipherOutputStream

public CipherOutputStream(OutputStream os,
                          Cipher c)

Creates a new CipherOutputStream instance for an OutputStream and a Cipher.

Parameters:

os - the output stream to write data to.

c - the cipher to process the data with.

CipherOutputStream

protected CipherOutputStream(OutputStream os)

Creates a new CipherOutputStream instance for an OutputStream without a cipher.

A NullCipher is created to process the data.

Parameters:

os - the output stream to write the data to.

Method Detail

write

public void write(int b)
           throws IOException

Writes the single byte to this cipher output stream.

Overrides:

write in class FilterOutputStream

Parameters:

b - the byte to write.

Throws:

IOException - if an error occurs.

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

Writes the len bytes from buffer b starting at offset off to this cipher output stream.

Overrides:

write in class FilterOutputStream

Parameters:

b - the buffer.

off - the offset to start at.

len - the number of bytes.

Throws:

IOException - if an error occurs.

flush

public void flush()
           throws IOException

Flushes this cipher output stream.

Specified by:

flush in interface Flushable

Overrides:

flush in class FilterOutputStream

Throws:

IOException - if an error occurs

close

public void close()
           throws IOException

Close this cipher output stream.

On the underlying cipher doFinal will be invoked, and any buffered bytes from the cipher are also written out, and the cipher is reset to its initial state. The underlying output stream is also closed.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class FilterOutputStream

Throws:

IOException - if an error occurs.