java.security
Class DigestInputStream
- Closeable
DigestInputStream is a class that ties an InputStream with a
MessageDigest. The Message Digest is used by the class to
update it self as bytes are read from the InputStream.
The updating to the digest depends on the on flag which is set
to true by default to tell the class to update the data
in the message digest.
MessageDigest | getMessageDigest()- Returns the MessageDigest associated with this DigestInputStream
|
void | on(boolean on)- Sets the flag specifing if this DigestInputStream updates the
digest in the write() methods.
|
int | read()- Reads a byte from the input stream and updates the digest.
|
int | read(byte[] b, int off, int len)- Reads bytes from the input stream and updates the digest.
|
void | setMessageDigest(MessageDigest digest)- Sets the current MessageDigest to current parameter
|
String | toString()- Converts the input stream and underlying message digest to a string.
|
clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait |
DigestInputStream
public DigestInputStream(InputStream stream,
MessageDigest digest) Constructs a new DigestInputStream.
It associates a MessageDigest with the stream to
compute the stream as data is written.
stream - An InputStream to associate this stream withdigest - A MessageDigest to hash the stream with
getMessageDigest
public MessageDigest getMessageDigest()
Returns the MessageDigest associated with this DigestInputStream
- The MessageDigest used to hash this stream
on
public void on(boolean on)
Sets the flag specifing if this DigestInputStream updates the
digest in the write() methods. The default is on;
on - True means it digests stream, false means it does not
read
public int read()
throws IOException Reads a byte from the input stream and updates the digest.
This method reads the underlying input stream and if the
on flag is true then updates the message digest.
- read in interface FilterInputStream
- Returns a byte from the input stream, -1 is returned to indicate that
the end of stream was reached before this read call
IOException - if an IO error occurs in the underlying input stream,
this error is thrown
read
public int read(byte[] b,
int off,
int len)
throws IOException Reads bytes from the input stream and updates the digest.
This method reads the underlying input stream and if the
on flag is true then updates the message digest.
- read in interface FilterInputStream
b - a byte array to store the data from the input streamoff - an offset to start at in the arraylen - length of data to read
- Returns count of bytes read, -1 is returned to indicate that
the end of stream was reached before this read call
IOException - if an IO error occurs in the underlying input stream,
this error is thrown
setMessageDigest
public void setMessageDigest(MessageDigest digest)
Sets the current MessageDigest to current parameter
digest - A MessageDigest to associate with this stream
toString
public String toString()
Converts the input stream and underlying message digest to a string.
- toString in interface Object
- A string representing the input stream and message digest.
DigestInputStream.java --- An Input stream tied to a message digest
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