DATACMNS-323 - PageImpl returns correct number of pages for use with content only.

So far, the PageImpl class returned 0 as total number of pages if set up from a plain List. This returns 1 now (as it should be). We've also adapted the hasNextPage() implementation to correctly calculate whether a next page is available.

Author: odrotbohm

src/main/java/org/springframework/data/domain/PageImpl.java

@@ -84,7 +84,7 @@ public int getSize() {
 	 * @see org.springframework.data.domain.Page#getTotalPages()
 	 */
 	public int getTotalPages() {
-		return getSize() == 0 ? 0 : (int) Math.ceil((double) total / (double) getSize());
+		return getSize() == 0 ? 1 : (int) Math.ceil((double) total / (double) getSize());
 	}
 
 	/*
@@ -124,7 +124,7 @@ public boolean isFirstPage() {
 	 * @see org.springframework.data.domain.Page#hasNextPage()
 	 */
 	public boolean hasNextPage() {
-		return (getNumber() + 1) * getSize() < total;
+		return getNumber() + 1 < getTotalPages();
 	}
 
 	/*

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

@@ -106,11 +106,24 @@ public void createsPageForEmptyContentCorrectly() {
 		assertThat(page.getSize(), is(0));
 		assertThat(page.getSort(), is((Sort) null));
 		assertThat(page.getTotalElements(), is(0L));
-		assertThat(page.getTotalPages(), is(0));
+		assertThat(page.getTotalPages(), is(1));
 		assertThat(page.hasNextPage(), is(false));
 		assertThat(page.hasPreviousPage(), is(false));
 		assertThat(page.isFirstPage(), is(true));
 		assertThat(page.isLastPage(), is(true));
 		assertThat(page.hasContent(), is(false));
 	}
+
+	/**
+	 * @see DATACMNS-323
+	 */
+	@Test
+	public void returnsCorrectTotalPages() {
+
+		Page<String> page = new PageImpl<String>(Arrays.asList("a"));
+
+		assertThat(page.getTotalPages(), is(1));
+		assertThat(page.hasNextPage(), is(false));
+		assertThat(page.hasPreviousPage(), is(false));
+	}
 }