IT. Expert System.

All Implemented Interfaces:

Closeable, AutoCloseable

public class DigestInputStream
extends FilterInputStream

• Field Summary

  Fields

  Modifier and Type	Field and Description
  protected MessageDigest	digest The message digest for this stream.

  • Fields inherited from class java.io.FilterInputStream

    in

• Constructor Summary

  Constructors

  Constructor and Description
  DigestInputStream(InputStream stream, MessageDigest digest) Constructs a new instance of this DigestInputStream, using the given stream and the digest.

• Method Summary

  Methods

  Modifier and Type	Method and Description
  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[] b, int off, int len) Reads len bytes into the specified byte[], starting from the specified offset.
  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.

  • Methods inherited from class java.io.FilterInputStream

    available, close, mark, markSupported, reset, skip

  • Methods inherited from class java.io.InputStream

    read

  • Methods inherited from class java.lang.Object

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

• Field Detail

  • digest

    protected MessageDigest digest

    The message digest for this stream.

• Constructor Detail

  • DigestInputStream

    public DigestInputStream(InputStream stream,
                     MessageDigest digest)

    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 - the input stream.

    digest - the message digest.

• Method Detail

  • getMessageDigest

    public MessageDigest getMessageDigest()

    Returns the message digest for this stream.

    Returns:

    the message digest for this stream.

  • setMessageDigest

    public void setMessageDigest(MessageDigest digest)

    Sets the message digest which this stream will use.

    Parameters:

    digest - the message digest which this stream will use.

  • 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 on(boolean).

    This operation is blocking.

    Overrides:

    read in class FilterInputStream

    Returns:

    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

    Reads len bytes into the specified byte[], starting from the specified offset. Updates the digest if this function is on(boolean).

    This operation is blocking.

    Overrides:

    read in class FilterInputStream

    Parameters:

    b - the byte array in which to store the bytes

    off - the initial position in b to store the bytes read from this stream

    len - the maximum number of bytes to store in b

    Returns:

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

    Throws:

    IOException - if reading the source stream causes an IOException

  • on

    public void on(boolean on)

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

    Parameters:

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

    See Also:

    MessageDigest

  • toString

    public String toString()

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

    Overrides:

    toString in class Object

    Returns:

    a printable representation for this DigestInputStream.