public class CipherOutputStream extends FilterOutputStream
For example, if the cipher is initialized for encryption, the CipherOutputStream will attempt to encrypt data before writing out the encrypted data.
This class adheres strictly to the semantics, especially the failure semantics, of its ancestor classes java.io.OutputStream and java.io.FilterOutputStream. This class has exactly those methods specified in its ancestor classes, and overrides them all. Moreover, this class catches all exceptions that are not thrown by its ancestor classes. In particular, this class catches BadPaddingException and other exceptions thrown by failed integrity checks during decryption. These exceptions are not re-thrown, so the client will not be informed that integrity checks failed. Because of this behavior, this class may not be suitable for use with decryption in an authenticated mode of operation (e.g. GCM) if the application requires explicit notification when authentication fails. Such an application can use the Cipher API directly as an alternative to using this class.
It is crucial for a programmer using this class not to use methods that are not defined or overriden in this class (such as a new method or constructor that is later added to one of the super classes), because the design and implementation of those methods are unlikely to have considered security impact with regard to CipherOutputStream.
OutputStream, 
FilterOutputStream, 
Cipher, 
CipherInputStreamout| Modifier | Constructor and Description | 
|---|---|
| protected  | CipherOutputStream(OutputStream os)Constructs a CipherOutputStream from an OutputStream without
 specifying a Cipher. | 
|   | CipherOutputStream(OutputStream os,
                  Cipher c)Constructs a CipherOutputStream from an OutputStream and a
 Cipher. | 
| Modifier and Type | Method and Description | 
|---|---|
| void | close()Closes this output stream and releases any system resources
 associated with this stream. | 
| void | flush()Flushes this output stream by forcing any buffered output bytes
 that have already been processed by the encapsulated cipher object
 to be written out. | 
| void | write(byte[] b)Writes  b.lengthbytes from the specified byte array
 to this output stream. | 
| void | write(byte[] b,
     int off,
     int len)Writes  lenbytes from the specified byte array
 starting at offsetoffto this output stream. | 
| void | write(int b)Writes the specified byte to this output stream. | 
public CipherOutputStream(OutputStream os, Cipher c)
os - the OutputStream objectc - an initialized Cipher objectprotected CipherOutputStream(OutputStream os)
os - the OutputStream objectpublic void write(int b)
           throws IOException
write in class FilterOutputStreamb - the byte.IOException - if an I/O error occurs.public void write(byte[] b)
           throws IOException
b.length bytes from the specified byte array
 to this output stream.
 
 The write method of
 CipherOutputStream calls the write
 method of three arguments with the three arguments
 b, 0, and b.length.
write in class FilterOutputStreamb - the data.NullPointerException - if b is null.IOException - if an I/O error occurs.write(byte[], int, int)public void write(byte[] b,
                  int off,
                  int len)
           throws IOException
len bytes from the specified byte array
 starting at offset off to this output stream.write in class FilterOutputStreamb - the data.off - the start offset in the data.len - the number of bytes to write.IOException - if an I/O error occurs.FilterOutputStream.write(int)public void flush()
           throws IOException
Any bytes buffered by the encapsulated cipher
 and waiting to be processed by it will not be written out. For example,
 if the encapsulated cipher is a block cipher, and the total number of
 bytes written using one of the write methods is less than
 the cipher's block size, no bytes will be written out.
flush in interface Flushableflush in class FilterOutputStreamIOException - if an I/O error occurs.FilterOutputStream.outpublic void close()
           throws IOException
 This method invokes the doFinal method of the encapsulated
 cipher object, which causes any bytes buffered by the encapsulated
 cipher to be processed. The result is written out by calling the
 flush method of this output stream.
 
 This method resets the encapsulated cipher object to its initial state
 and calls the close method of the underlying output
 stream.
close in interface Closeableclose in interface AutoCloseableclose in class FilterOutputStreamIOException - if an I/O error occurs.FilterOutputStream.flush(), 
FilterOutputStream.out Submit a bug or feature 
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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