java/security/DigestInputStream.java

36  * A transparent stream that updates the associated message digest using
39  * <p>To complete the message digest computation, call one of the
40  * {@code digest} methods on the associated message
41  * digest after your calls to one of this digest input stream's
47  * results in an update on the message digest.  But when it is off,
48  * the message digest is not updated. The default is for the stream
51  * <p>Note that digest objects can compute only one digest (see
54  * retain a handle onto the digest object, and clone it for each
55  * digest to be computed, leaving the original digest untouched.
73      * The message digest associated with this stream.
75     protected MessageDigest digest;
78      * Creates a digest input stream, using the specified input stream
79      * and message digest.
83      * @param digest the message digest to associate with this stream.
85     public DigestInputStream(InputStream stream, MessageDigest digest) {
87         setMessageDigest(digest);
91      * Returns the message digest associated with this stream.
93      * @return the message digest associated with this stream.
97         return digest;
101      * Associates the specified message digest with this stream.
103      * @param digest the message digest to be associated with this stream.
106     public void setMessageDigest(MessageDigest digest) {
107         this.digest = digest;
111      * Reads a byte, and updates the message digest (if the digest
114      * digest function is on (see {@link #on(boolean) on}), this method
115      * will then call {@code update} on the message digest associated
127             digest.update((byte)ch);
133      * Reads into a byte array, and updates the message digest (if the
134      * digest function is on).  That is, this method reads up to
138      * read. If the digest function is on (see
140      * on the message digest associated with this stream, passing it
164             digest.update(b, off, result);
170      * Turns the digest function on or off. The default is on.  When
172      * update on the message digest.  But when it is off, the message
173      * digest is not updated.
175      * @param on true to turn the digest function on, false to turn
183      * Prints a string representation of this digest input stream and
184      * its associated message digest object.
187          return "[Digest Input Stream] " + digest.toString();