DATACMNS-713 - PageImpl now adapts total if necessary.

On a last page the total handed into a PageImpl constructor might not necessarily fit the content as there's the change of an insertion or deletion between the calculated count and the retrieval of the content. We now leniently mitigate those differences if the page created is the last page of the result.

Related tickets: DATAJPA-728, DATACMNS-615.

src/test/java/org/springframework/data/domain/PageImplUnitTests.java

@@ -128,14 +128,6 @@ public class PageImplUnitTests {
 		assertThat(page.hasPrevious(), is(false));
 	}
 
-	/**
-	 * @see DATACMNS-615
-	 */
-	@Test(expected = IllegalArgumentException.class)
-	public void rejectsTotalLessThanContentLength() {
-		new PageImpl<String>(Arrays.asList("foo", "bar"), new PageRequest(0, 10), 1);
-	}
-
 	/**
 	 * @see DATACMNS-635
 	 */
@@ -153,4 +145,38 @@ public class PageImplUnitTests {
 		assertThat(transformed.getContent(), hasSize(2));
 		assertThat(transformed.getContent(), contains(3, 3));
 	}
+
+	/**
+	 * @see DATACMNS-713
+	 */
+	@Test
+	public void adaptsTotalForLastPageOnIntermediateDeletion() {
+		assertThat(new PageImpl<String>(Arrays.asList("foo", "bar"), new PageRequest(0, 5), 3).getTotalElements(), is(2L));
+	}
+
+	/**
+	 * @see DATACMNS-713
+	 */
+	@Test
+	public void adaptsTotalForLastPageOnIntermediateInsertion() {
+		assertThat(new PageImpl<String>(Arrays.asList("foo", "bar"), new PageRequest(0, 5), 1).getTotalElements(), is(2L));
+	}
+
+	/**
+	 * @see DATACMNS-713
+	 */
+	@Test
+	public void adaptsTotalForLastPageOnIntermediateDeletionOnLastPate() {
+		assertThat(new PageImpl<String>(Arrays.asList("foo", "bar"), new PageRequest(1, 10), 13).getTotalElements(),
+				is(12L));
+	}
+
+	/**
+	 * @see DATACMNS-713
+	 */
+	@Test
+	public void adaptsTotalForLastPageOnIntermediateInsertionOnLastPate() {
+		assertThat(new PageImpl<String>(Arrays.asList("foo", "bar"), new PageRequest(1, 10), 11).getTotalElements(),
+				is(12L));
+	}
 }