DATACMNS-1750 - Refrain from inspecting Page contents if first item is null.

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

@@ -116,7 +116,7 @@ public class PageImpl<T> extends Chunk<T> implements Page<T> {
 		String contentType = "UNKNOWN";
 		List<T> content = getContent();
 
-		if (content.size() > 0) {
+		if (!content.isEmpty() && content.get(0) != null) {
 			contentType = content.get(0).getClass().getName();
 		}
 

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

@@ -28,6 +28,7 @@ import org.junit.jupiter.api.Test;
  * Unit test for {@link PageImpl}.
  *
  * @author Oliver Gierke
+ * @author Mark Paluch
  */
 class PageImplUnitTests {
 
@@ -185,4 +186,13 @@ class PageImplUnitTests {
 		assertThat(page.hasPrevious()).isFalse();
 		assertThat(page.hasNext()).isFalse();
 	}
+
+	@Test // DATACMNS-1750
+	void toStringShouldNotInspectNullInstances() {
+
+		Page<Integer> page = new PageImpl<>(Collections.singletonList(null));
+
+		assertThat(page).hasToString("Page 1 of 1 containing UNKNOWN instances");
+	}
+
 }