public class

CipherInputStream

extends FilterInputStream
java.lang.Object
   ↳ java.io.InputStream
     ↳ java.io.FilterInputStream
       ↳ javax.crypto.CipherInputStream

Class Overview

This class wraps an InputStream and a cipher so that read() methods return data that are read from the underlying InputStream and processed by the cipher.

The cipher must be initialized for the requested operation before being used by a CipherInputStream. For example, if a cipher initialized for decryption is used with a CipherInputStream, the CipherInputStream tries to read the data an decrypt them before returning.

Summary

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Inherited Fields
From class java.io.FilterInputStream
Public Constructors
CipherInputStream(InputStream is, Cipher c)
Creates a new CipherInputStream instance for an InputStream and a cipher.
Protected Constructors
CipherInputStream(InputStream is)
Creates a new CipherInputStream instance for an InputStream without a cipher.
Public Methods
int available()
Returns the number of bytes available without blocking.
void close()
Closes this CipherInputStream, also closes the underlying input stream and call doFinal on the cipher object.
boolean markSupported()
Returns whether this input stream supports mark and reset, which it does not.
int read(byte[] b, int off, int len)
Reads the next len bytes from this input stream into buffer b starting at offset off.
int read(byte[] b)
Reads the next b.length bytes from this input stream into buffer b.
int read()
Reads the next byte from this cipher input stream.
long skip(long n)
Skips up to n bytes from this input stream.
[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 CipherInputStream (InputStream is, Cipher c)

Since: API Level 1

Creates a new CipherInputStream instance for an InputStream and a cipher.

Parameters
is the input stream to read data from.
c the cipher to process the data with.

Protected Constructors

protected CipherInputStream (InputStream is)

Since: API Level 1

Creates a new CipherInputStream instance for an InputStream without a cipher.

A NullCipher is created and used to process the data.

Parameters
is the input stream to read data from.

Public Methods

public int available ()

Since: API Level 1

Returns the number of bytes available without blocking.

Returns
  • the number of bytes available, currently zero.
Throws
IOException if an error occurs

public void close ()

Since: API Level 1

Closes this CipherInputStream, also closes the underlying input stream and call doFinal on the cipher object.

Throws
IOException if an error occurs.

public boolean markSupported ()

Since: API Level 1

Returns whether this input stream supports mark and reset, which it does not.

Returns
  • false, since this input stream does not support mark and reset.

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

Since: API Level 1

Reads the next len bytes from this input stream into buffer b starting at offset off.

if b is null, the next len bytes are read and discarded.

Parameters
b the buffer to be filled with data.
off the offset to start in the buffer.
len the maximum number of bytes to read.
Returns
  • the number of bytes filled into buffer b, or -1 of the of the stream is reached.
Throws
IOException if an error occurs.
NullPointerException if the underlying input stream is null.

public int read (byte[] b)

Since: API Level 1

Reads the next b.length bytes from this input stream into buffer b.

Parameters
b the buffer to be filled with data.
Returns
  • the number of bytes filled into buffer b, or -1 if the end of the stream is reached.
Throws
IOException if an error occurs.

public int read ()

Since: API Level 1

Reads the next byte from this cipher input stream.

Returns
  • the next byte, or -1 if the end of the stream is reached.
Throws
IOException if an error occurs.

public long skip (long n)

Since: API Level 1

Skips up to n bytes from this input stream.

The number of bytes skipped depends on the result of a call to available. The smaller of n and the result are the number of bytes being skipped.

Parameters
n the number of bytes that should be skipped.
Returns
  • the number of bytes actually skipped.
Throws
IOException if an error occurs