CipherInputStream
open class CipherInputStream : FilterInputStream
kotlin.Any | |||
↳ | java.io.InputStream | ||
↳ | java.io.FilterInputStream | ||
↳ | javax.crypto.CipherInputStream |
A CipherInputStream is composed of an InputStream and a Cipher so that read() methods return data that are read in from the underlying InputStream but have been additionally processed by the Cipher. The Cipher must be fully initialized before being used by a CipherInputStream.
For example, if the Cipher is initialized for decryption, the CipherInputStream will attempt to read in data and decrypt them, before returning the decrypted data.
This class adheres strictly to the semantics, especially the failure semantics, of its ancestor classes java.io.FilterInputStream and java.io.InputStream. 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, the skip
method skips, and the available
method counts only data that have been processed by the encapsulated Cipher.
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 CipherInputStream.
Summary
Public constructors | |
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CipherInputStream(is: InputStream!, c: Cipher!) Constructs a CipherInputStream from an InputStream and a Cipher. |
Protected constructors | |
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CipherInputStream(is: InputStream!) Constructs a CipherInputStream from an InputStream without specifying a Cipher. |
Public methods | |
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open Int |
Returns the number of bytes that can be read from this input stream without blocking. |
open Unit |
close() Closes this input stream and releases any system resources associated with the stream. |
open Boolean |
Tests if this input stream supports the |
open Int |
read() Reads the next byte of data from this input stream. |
open Int |
Reads up to |
open Int |
Reads up to |
open Long |
Skips |
Inherited functions | |
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Inherited properties | |
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Public constructors
CipherInputStream
CipherInputStream(
is: InputStream!,
c: Cipher!)
Constructs a CipherInputStream from an InputStream and a Cipher.
Note: if the specified input stream or cipher is null, a NullPointerException may be thrown later when they are used.
Parameters | |
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is |
InputStream!: the to-be-processed input stream |
c |
Cipher!: an initialized Cipher object |
Protected constructors
CipherInputStream
protected CipherInputStream(is: InputStream!)
Constructs a CipherInputStream from an InputStream without specifying a Cipher. This has the effect of constructing a CipherInputStream using a NullCipher.
Note: if the specified input stream is null, a NullPointerException may be thrown later when it is used.
Parameters | |
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is |
InputStream!: the to-be-processed input stream |
Public methods
available
open fun available(): Int
Returns the number of bytes that can be read from this input stream without blocking. The available
method of InputStream
returns 0
. This method should be overridden by subclasses.
Return | |
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Int |
the number of bytes that can be read from this input stream without blocking. |
Exceptions | |
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java.io.IOException |
if an I/O error occurs. |
java.io.IOException |
if an I/O error occurs. |
close
open fun close(): Unit
Closes this input stream and releases any system resources associated with the stream.
The close
method of CipherInputStream
calls the close
method of its underlying input stream.
Exceptions | |
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java.lang.Exception |
if this resource cannot be closed |
java.io.IOException |
if an I/O error occurs. |
java.io.IOException |
if an I/O error occurs. |
markSupported
open fun markSupported(): Boolean
Tests if this input stream supports the mark
and reset
methods, which it does not.
Return | |
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Boolean |
false , since this class does not support the mark and reset methods. |
read
open fun read(): Int
Reads the next byte of data from this input stream. The value byte is returned as an int
in the range 0
to 255
. If no byte is available because the end of the stream has been reached, the value -1
is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.
Return | |
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Int |
the next byte of data, or -1 if the end of the stream is reached. |
Exceptions | |
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java.io.IOException |
if an I/O error occurs. |
java.io.IOException |
if an I/O error occurs. |
read
open fun read(b: ByteArray!): Int
Reads up to b.length
bytes of data from this input stream into an array of bytes.
The read
method of InputStream
calls the read
method of three arguments with the arguments b
, 0
, and b.length
.
Parameters | |
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b |
ByteArray!: the buffer into which the data is read. |
Return | |
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Int |
the total number of bytes read into the buffer, or -1 is there is no more data because the end of the stream has been reached. |
Exceptions | |
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java.io.IOException |
If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs. |
java.lang.NullPointerException |
if b is null . |
java.io.IOException |
if an I/O error occurs. |
read
open fun read(
b: ByteArray!,
off: Int,
len: Int
): Int
Reads up to len
bytes of data from this input stream into an array of bytes. This method blocks until some input is available. If the first argument is null,
up to len
bytes are read and discarded.
Parameters | |
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b |
ByteArray!: the buffer into which the data is read. |
off |
Int: the start offset in the destination array buf |
len |
Int: the maximum number of bytes read. |
Return | |
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Int |
the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached. |
Exceptions | |
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java.io.IOException |
If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs. |
java.lang.NullPointerException |
If b is null . |
java.lang.IndexOutOfBoundsException |
If off is negative, len is negative, or len is greater than b.length - off |
java.io.IOException |
if an I/O error occurs. |
See Also
skip
open fun skip(n: Long): Long
Skips n
bytes of input from the bytes that can be read from this input stream without blocking.
Fewer bytes than requested might be skipped. The actual number of bytes skipped is equal to n
or the result of a call to #available(), whichever is smaller. If n
is less than zero, no bytes are skipped.
The actual number of bytes skipped is returned.
Parameters | |
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n |
Long: the number of bytes to be skipped. |
Return | |
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Long |
the actual number of bytes skipped. |
Exceptions | |
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java.io.IOException |
if in.skip(n) throws an IOException. |
java.io.IOException |
if an I/O error occurs. |