public class DigestInputStream extends FilterInputStream
To complete the message digest computation, call one of the
digest methods on the associated message
digest after your calls to one of this digest input stream's
It is possible to turn this stream on or off (see
on). When it is on, a call to one of the
results in an update on the message digest. But when it is off,
the message digest is not updated. The default is for the stream
to be on.
Note that digest objects can compute only one digest (see
so that in order to compute intermediate digests, a caller should
retain a handle onto the digest object, and clone it for each
digest to be computed, leaving the orginal digest untouched.
|Modifier and Type||Field and Description|
The message digest associated with this stream.
|Constructor and Description|
Creates a digest input stream, using the specified input stream and message digest.
|Modifier and Type||Method and Description|
Returns the message digest associated with this stream.
Turns the digest function on or off.
Reads a byte, and updates the message digest (if the digest function is on).
Reads into a byte array, and updates the message digest (if the digest function is on).
Associates the specified message digest with this stream.
Prints a string representation of this digest input stream and its associated message digest object.
available, close, mark, markSupported, read, reset, skip
protected MessageDigest digest
public MessageDigest getMessageDigest()
public void setMessageDigest(MessageDigest digest)
digest- the message digest to be associated with this stream.
public int read() throws IOException
on), this method will then call
updateon the message digest associated with this stream, passing it the byte read.
public int read(byte b, int off, int len) throws IOException
lenbytes from the input stream into the array
b, starting at offset
off. This method blocks until the data is actually read. If the digest function is on (see
on), this method will then call
updateon the message digest associated with this stream, passing it the data.
b- the array into which the data is read.
off- the starting offset into
bof where the data should be placed.
len- the maximum number of bytes to be read from the input stream into b, starting at offset
lenif the end of the stream is reached prior to reading
lenbytes. -1 is returned if no bytes were read because the end of the stream had already been reached when the call was made.
IOException- if an I/O error occurs.
MessageDigest.update(byte, int, int)
public void on(boolean on)
readmethods results in an update on the message digest. But when it is off, the message digest is not updated.
on- true to turn the digest function on, false to turn it off.
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For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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