Exposed the constructor of Note class

Additionally, defined the NoteMap.getNote method which returns a Note
instance.  These changes were necessary to enable implementation of
the NoteMerger interface (the merge method needs to instantiate a
Note) and to enable direct use of NoteMerger which expects instances
of Note class as its paramters.  Implementing creation of code review
summary notes in Gerrit [1] will make use of both of these features.

[1] https://review.source.android.com/#change,20045

Change-Id: I627aefcedcd3434deecd63fa1d3e90e303b385ac
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/notes/LeafBucketTest.java

 	@Test
 	public void testEmpty() {
 		LeafBucket b = new LeafBucket(0);
-		assertNull(b.get(id(0x00), null));
-		assertNull(b.get(id(0x01), null));
-		assertNull(b.get(id(0xfe), null));
+		assertNull(b.getNote(id(0x00), null));
+		assertNull(b.getNote(id(0x01), null));
+		assertNull(b.getNote(id(0xfe), null));
 	}
 
 	@Test
 		b.parseOneEntry(id(0x44), id(0x84));
 		b.parseOneEntry(id(0x55), id(0x85));
 
-		assertNull(b.get(id(0x01), null));
-		assertEquals(id(0x81), b.get(id(0x11), null));
-		assertEquals(id(0x82), b.get(id(0x22), null));
-		assertEquals(id(0x83), b.get(id(0x33), null));
-		assertEquals(id(0x84), b.get(id(0x44), null));
-		assertEquals(id(0x85), b.get(id(0x55), null));
-		assertNull(b.get(id(0x66), null));
+		assertNull(b.getNote(id(0x01), null));
+		assertEquals(id(0x81), b.getNote(id(0x11), null).getData());
+		assertEquals(id(0x82), b.getNote(id(0x22), null).getData());
+		assertEquals(id(0x83), b.getNote(id(0x33), null).getData());
+		assertEquals(id(0x84), b.getNote(id(0x44), null).getData());
+		assertEquals(id(0x85), b.getNote(id(0x55), null).getData());
+		assertNull(b.getNote(id(0x66), null));
 	}
 
 	@Test
 		assertSame(b, b.set(id(0x44), id(0x84), null));
 		assertSame(b, b.set(id(0x55), id(0x85), null));
 
-		assertNull(b.get(id(0x01), null));
-		assertEquals(id(0x81), b.get(id(0x11), null));
-		assertEquals(id(0x82), b.get(id(0x22), null));
-		assertEquals(id(0x83), b.get(id(0x33), null));
-		assertEquals(id(0x84), b.get(id(0x44), null));
-		assertEquals(id(0x85), b.get(id(0x55), null));
-		assertNull(b.get(id(0x66), null));
+		assertNull(b.getNote(id(0x01), null));
+		assertEquals(id(0x81), b.getNote(id(0x11), null).getData());
+		assertEquals(id(0x82), b.getNote(id(0x22), null).getData());
+		assertEquals(id(0x83), b.getNote(id(0x33), null).getData());
+		assertEquals(id(0x84), b.getNote(id(0x44), null).getData());
+		assertEquals(id(0x85), b.getNote(id(0x55), null).getData());
+		assertNull(b.getNote(id(0x66), null));
 	}
 
 	@Test
 		assertSame(b, b.set(id(0x22), id(0x82), null));
 		assertSame(b, b.set(id(0x11), id(0x81), null));
 
-		assertNull(b.get(id(0x01), null));
-		assertEquals(id(0x81), b.get(id(0x11), null));
-		assertEquals(id(0x82), b.get(id(0x22), null));
-		assertEquals(id(0x83), b.get(id(0x33), null));
-		assertEquals(id(0x84), b.get(id(0x44), null));
-		assertEquals(id(0x85), b.get(id(0x55), null));
-		assertNull(b.get(id(0x66), null));
+		assertNull(b.getNote(id(0x01), null));
+		assertEquals(id(0x81), b.getNote(id(0x11), null).getData());
+		assertEquals(id(0x82), b.getNote(id(0x22), null).getData());
+		assertEquals(id(0x83), b.getNote(id(0x33), null).getData());
+		assertEquals(id(0x84), b.getNote(id(0x44), null).getData());
+		assertEquals(id(0x85), b.getNote(id(0x55), null).getData());
+		assertNull(b.getNote(id(0x66), null));
 	}
 
 	@Test
 		assertSame(b, b.set(id(0x22), id(0x82), null));
 		assertSame(b, b.set(id(0x44), id(0x84), null));
 
-		assertNull(b.get(id(0x01), null));
-		assertEquals(id(0x81), b.get(id(0x11), null));
-		assertEquals(id(0x82), b.get(id(0x22), null));
-		assertEquals(id(0x83), b.get(id(0x33), null));
-		assertEquals(id(0x84), b.get(id(0x44), null));
-		assertEquals(id(0x85), b.get(id(0x55), null));
-		assertNull(b.get(id(0x66), null));
+		assertNull(b.getNote(id(0x01), null));
+		assertEquals(id(0x81), b.getNote(id(0x11), null).getData());
+		assertEquals(id(0x82), b.getNote(id(0x22), null).getData());
+		assertEquals(id(0x83), b.getNote(id(0x33), null).getData());
+		assertEquals(id(0x84), b.getNote(id(0x44), null).getData());
+		assertEquals(id(0x85), b.getNote(id(0x55), null).getData());
+		assertNull(b.getNote(id(0x66), null));
 	}
 
 	@Test
 		LeafBucket b = new LeafBucket(0);
 
 		assertSame(b, b.set(id(0x11), id(0x81), null));
-		assertEquals(id(0x81), b.get(id(0x11), null));
+		assertEquals(id(0x81), b.getNote(id(0x11), null).getData());
 
 		assertSame(b, b.set(id(0x11), id(0x01), null));
-		assertEquals(id(0x01), b.get(id(0x11), null));
+		assertEquals(id(0x01), b.getNote(id(0x11), null).getData());
 	}
 
 	@Test
 	public void testRemoveMissingNote() throws IOException {
 		LeafBucket b = new LeafBucket(0);
-		assertNull(b.get(id(0x11), null));
+		assertNull(b.getNote(id(0x11), null));
 		assertSame(b, b.set(id(0x11), null, null));
-		assertNull(b.get(id(0x11), null));
+		assertNull(b.getNote(id(0x11), null));
 	}
 
 	@Test
 
 		assertSame(b, b.set(id(0x11), null, null));
 
-		assertNull(b.get(id(0x01), null));
-		assertNull(b.get(id(0x11), null));
-		assertEquals(id(0x82), b.get(id(0x22), null));
-		assertEquals(id(0x83), b.get(id(0x33), null));
-		assertEquals(id(0x84), b.get(id(0x44), null));
-		assertEquals(id(0x85), b.get(id(0x55), null));
-		assertNull(b.get(id(0x66), null));
+		assertNull(b.getNote(id(0x01), null));
+		assertNull(b.getNote(id(0x11), null));
+		assertEquals(id(0x82), b.getNote(id(0x22), null).getData());
+		assertEquals(id(0x83), b.getNote(id(0x33), null).getData());
+		assertEquals(id(0x84), b.getNote(id(0x44), null).getData());
+		assertEquals(id(0x85), b.getNote(id(0x55), null).getData());
+		assertNull(b.getNote(id(0x66), null));
 	}
 
 	@Test
 
 		assertSame(b, b.set(id(0x33), null, null));
 
-		assertNull(b.get(id(0x01), null));
-		assertEquals(id(0x81), b.get(id(0x11), null));
-		assertEquals(id(0x82), b.get(id(0x22), null));
-		assertNull(b.get(id(0x33), null));
-		assertEquals(id(0x84), b.get(id(0x44), null));
-		assertEquals(id(0x85), b.get(id(0x55), null));
-		assertNull(b.get(id(0x66), null));
+		assertNull(b.getNote(id(0x01), null));
+		assertEquals(id(0x81), b.getNote(id(0x11), null).getData());
+		assertEquals(id(0x82), b.getNote(id(0x22), null).getData());
+		assertNull(b.getNote(id(0x33), null));
+		assertEquals(id(0x84), b.getNote(id(0x44), null).getData());
+		assertEquals(id(0x85), b.getNote(id(0x55), null).getData());
+		assertNull(b.getNote(id(0x66), null));
 	}
 
 	@Test
 
 		assertSame(b, b.set(id(0x55), null, null));
 
-		assertNull(b.get(id(0x01), null));
-		assertEquals(id(0x81), b.get(id(0x11), null));
-		assertEquals(id(0x82), b.get(id(0x22), null));
-		assertEquals(id(0x83), b.get(id(0x33), null));
-		assertEquals(id(0x84), b.get(id(0x44), null));
-		assertNull(b.get(id(0x55), null));
-		assertNull(b.get(id(0x66), null));
+		assertNull(b.getNote(id(0x01), null));
+		assertEquals(id(0x81), b.getNote(id(0x11), null).getData());
+		assertEquals(id(0x82), b.getNote(id(0x22), null).getData());
+		assertEquals(id(0x83), b.getNote(id(0x33), null).getData());
+		assertEquals(id(0x84), b.getNote(id(0x44), null).getData());
+		assertNull(b.getNote(id(0x55), null));
+		assertNull(b.getNote(id(0x66), null));
 	}
 
 	@Test
 		LeafBucket b = new LeafBucket(0);
 
 		assertSame(b, b.set(id(0x11), id(0x81), null));
-		assertEquals(id(0x81), b.get(id(0x11), null));
+		assertEquals(id(0x81), b.getNote(id(0x11), null).getData());
 
 		assertNull(b.set(id(0x11), null, null));
-		assertNull(b.get(id(0x11), null));
+		assertNull(b.getNote(id(0x11), null));
 	}
 
 	private static AnyObjectId id(int first) {

org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java

 	}
 
 	@Override
-	ObjectId get(AnyObjectId objId, ObjectReader or) throws IOException {
+	Note getNote(AnyObjectId objId, ObjectReader or) throws IOException {
 		NoteBucket b = table[cell(objId)];
-		return b != null ? b.get(objId, or) : null;
+		return b != null ? b.getNote(objId, or) : null;
+
 	}
 
 	NoteBucket getBucket(int cell) {
 		}
 
 		@Override
-		ObjectId get(AnyObjectId objId, ObjectReader or) throws IOException {
-			return load(objId, or).get(objId, or);
+		Note getNote(AnyObjectId objId, ObjectReader or) throws IOException {
+			return load(objId, or).getNote(objId, or);
 		}
 
 		@Override

org.eclipse.jgit/src/org/eclipse/jgit/notes/LeafBucket.java

 		return -(low + 1);
 	}
 
-	ObjectId get(AnyObjectId objId, ObjectReader or) {
+	@Override
+	Note getNote(AnyObjectId objId, ObjectReader or) {
 		int idx = search(objId);
-		return 0 <= idx ? notes[idx].getData() : null;
+		return 0 <= idx ? notes[idx] : null;
 	}
 
 	Note get(int index) {

org.eclipse.jgit/src/org/eclipse/jgit/notes/Note.java

 	 * @param noteData
 	 *            the actual note data contained in this note
 	 */
-	Note(AnyObjectId noteOn, ObjectId noteData) {
+	public Note(AnyObjectId noteOn, ObjectId noteData) {
 		super(noteOn);
 		data = noteData;
 	}

org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteBucket.java

  * @see LeafBucket
  */
 abstract class NoteBucket {
-	abstract ObjectId get(AnyObjectId objId, ObjectReader reader)
+	abstract Note getNote(AnyObjectId objId, ObjectReader reader)
 			throws IOException;
 
 	abstract Iterator<Note> iterator(AnyObjectId objId, ObjectReader reader)

org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteMap.java

 	 *             a portion of the note space is not accessible.
 	 */
 	public ObjectId get(AnyObjectId id) throws IOException {
-		return root.get(id, reader);
+		Note n = root.getNote(id, reader);
+		return n == null ? null : n.getData();
+	}
+
+	/**
+	 * Lookup a note for a specific ObjectId.
+	 *
+	 * @param id
+	 *            the object to look for.
+	 * @return the note for the given object id, or null if no note exists.
+	 * @throws IOException
+	 *             a portion of the note space is not accessible.
+	 */
+	public Note getNote(AnyObjectId id) throws IOException {
+		return root.getNote(id, reader);
 	}
 
 	/**