java.security
Class DigestInputStream

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

All Implemented Interfaces:

Closeable

public class DigestInputStream
extends FilterInputStream

Field Summary

protected MessageDigest

digest

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

DigestInputStream(InputStream stream, MessageDigest digest)

Method Summary

MessageDigest	getMessageDigest() Returns the MessageDigest which the receiver uses when computing the hash.
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[] b, int off, int len) Reads at most count bytes from this FilterInputStream and stores them in byte array buffer starting at offset.
void	setMessageDigest(MessageDigest digest) Sets the MessageDigest which the receiver will use when computing the hash.
String	toString() Returns a string containing a concise, human-readable description of the receiver.

Methods inherited from class java.io.FilterInputStream

available, close, mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Field Detail

digest

protected MessageDigest digest

Constructor Detail

DigestInputStream

public DigestInputStream(InputStream stream,
                         MessageDigest digest)

Method Detail

getMessageDigest

public MessageDigest getMessageDigest()

Returns the MessageDigest which the receiver uses when computing the hash.

Returns:

MessageDigest the digest the receiver uses when computing the hash.

setMessageDigest

public void setMessageDigest(MessageDigest digest)

Sets the MessageDigest which the receiver will use when computing the hash.

Parameters:

digest - MessageDigest the digest to use when computing the hash.

See Also:

MessageDigest, on(boolean)

read

public int read()
         throws IOException

Reads the next byte and returns it as an int. Updates the digest for the byte if this function is enabled.

Overrides:

read in class FilterInputStream

Returns:

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

Throws:

IOException - If reading the source stream causes an IOException.

read

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

Description copied from class: FilterInputStream

Reads at most count bytes from this FilterInputStream and stores them in byte array buffer starting at offset. Answer the number of bytes actually read or -1 if no bytes were read and end of stream was encountered. This implementation reads bytes from the target stream.

Overrides:

read in class FilterInputStream

Parameters:

b - the byte array in which to store the read bytes.

off - the offset in buffer to store the read bytes.

len - the maximum number of bytes to store in buffer.

Returns:

the number of bytes actually read or -1 if end of stream.

Throws:

IOException - If the stream is already closed or another IOException occurs.

on

public void on(boolean on)

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

Parameters:

on - boolean true if the digest should be computed, and false otherwise.

See Also:

MessageDigest

toString

public String toString()

Returns a string containing a concise, human-readable description of the receiver.

Overrides:

toString in class Object

Returns:

String a printable representation for the receiver.