DigestInputStream

Added in API level 1

public class

DigestInputStream

extends FilterInputStream

java.lang.Object
↳	java.io.InputStream
	↳	java.io.FilterInputStream
		↳	java.security.DigestInputStream

Class Overview

DigestInputStream is a FilterInputStream which maintains an associated message digest.

Summary

Fields
protected MessageDigest	digest	The message digest for this stream.

[Expand]

Inherited Fields

From class java.io.FilterInputStream

Public Constructors
	DigestInputStream(InputStream stream, MessageDigest digest) Constructs a new instance of this `DigestInputStream`, using the given `stream` and the `digest`.

Public Methods
MessageDigest	getMessageDigest() Returns the message digest for this stream.
void	on(boolean on) Enables or disables the digest function (default is on).
int	read() Reads the next byte and returns it as an `int`.
int	read(byte[] buffer, int byteOffset, int byteCount) Reads up to `byteCount` bytes into `buffer`, starting at `byteOffset`.
void	setMessageDigest(MessageDigest digest) Sets the message digest which this stream will use.
String	toString() Returns a string containing a concise, human-readable description of this `DigestInputStream` including the digest.

[Expand]

Inherited Methods

From class java.io.FilterInputStream

int	available() Returns an estimated number of bytes that can be read or skipped without blocking for more input.
void	close() Closes this stream.
void	mark(int readlimit) Sets a mark position in this stream.
boolean	markSupported() Indicates whether this stream supports `mark()` and `reset()`.
int	read() Reads a single byte from the filtered stream and returns it as an integer in the range from 0 to 255.
int	read(byte[] buffer, int byteOffset, int byteCount) Reads up to `byteCount` bytes from this stream and stores them in the byte array `buffer` starting at `byteOffset`.
void	reset() Resets this stream to the last marked location.
long	skip(long byteCount) Skips `byteCount` bytes in this stream.

From class java.io.InputStream

int	available() Returns an estimated number of bytes that can be read or skipped without blocking for more input.
void	close() Closes this stream.
void	mark(int readlimit) Sets a mark position in this InputStream.
boolean	markSupported() Indicates whether this stream supports the `mark()` and `reset()` methods.
int	read(byte[] buffer) Equivalent to `read(buffer, 0, buffer.length)`.
abstract int	read() Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
int	read(byte[] buffer, int byteOffset, int byteCount) Reads up to `byteCount` bytes from this stream and stores them in the byte array `buffer` starting at `byteOffset`.
void	reset() Resets this stream to the last marked location.
long	skip(long byteCount) Skips at most `byteCount` bytes in this stream.

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

From interface java.io.Closeable

From interface java.lang.AutoCloseable

Fields

protected MessageDigest digest

Added in API level 1

The message digest for this stream.

Public Constructors

public DigestInputStream (InputStream stream, MessageDigest digest)

Added in API level 1

Constructs a new instance of this DigestInputStream, using the given stream and the digest.

Warning: passing a null source creates an invalid DigestInputStream. All operations on such a stream will fail.

Parameters
`stream`	`InputStream`: the input stream.
`digest`	`MessageDigest`: the message digest.

Public Methods

public MessageDigest getMessageDigest ()

Added in API level 1

Returns the message digest for this stream.

Returns
`MessageDigest`	the message digest for this stream.

public void on (boolean on)

Added in API level 1

Enables or disables the digest function (default is on).

Parameters
`on`	`boolean`: `true` if the digest should be computed, `false` otherwise.

See also:

MessageDigest

public int read ()

Added in API level 1

Reads the next byte and returns it as an int. Updates the digest for the byte if this function is on(boolean).

This operation is blocking.

Returns
`int`	the byte which was read or -1 at end of stream.

Throws
`IOException`	if reading the source stream causes an `IOException`.

public int read (byte[] buffer, int byteOffset, int byteCount)

Added in API level 1

Reads up to byteCount bytes into buffer, starting at byteOffset. Updates the digest if this function is on(boolean).

This operation is blocking.

Returns the number of bytes actually read or -1 if the end of the filtered stream has been reached while reading.

Parameters
`buffer`	`byte`
`byteOffset`	`int`
`byteCount`	`int`

Returns
`int`

Throws
`IOException`	if reading the source stream causes an `IOException`

public void setMessageDigest (MessageDigest digest)

Added in API level 1

Sets the message digest which this stream will use.

Parameters
`digest`	`MessageDigest`: the message digest which this stream will use.

public String toString ()

Added in API level 1

Returns a string containing a concise, human-readable description of this DigestInputStream including the digest.

Returns
`String`	a printable representation for this `DigestInputStream`.

Results

Interfaces

Classes

Enums

Exceptions

DigestInputStream

Class Overview

Summary

Fields

protected MessageDigest digest

Public Constructors

public DigestInputStream (InputStream stream, MessageDigest digest)

Public Methods

public MessageDigest getMessageDigest ()

public void on (boolean on)

public int read ()

public int read (byte[] buffer, int byteOffset, int byteCount)

public void setMessageDigest (MessageDigest digest)

public String toString ()