DATACMNS-1290 - Added support for timestamp values of type long.

The type long or Long is actually required for custom revision entities by Envers.

See also: https://github.com/spring-projects/spring-data-envers/issues/122
Original pull request: #282.

src/main/java/org/springframework/data/history/AnnotationRevisionMetadata.java

@@ -16,7 +16,9 @@
 package org.springframework.data.history;
 
 import java.lang.annotation.Annotation;
+import java.time.Instant;
 import java.time.LocalDateTime;
+import java.time.ZoneOffset;
 import java.util.Optional;
 
 import org.springframework.data.util.AnnotationDetectionFieldCallback;
@@ -29,12 +31,13 @@ import org.springframework.util.ReflectionUtils;
  * and returns the field's values on calls to {@link #getRevisionDate()} and {@link #getRevisionNumber()}.
  *
  * @author Oliver Gierke
+ * @author Jens Schauder
  */
 public class AnnotationRevisionMetadata<N extends Number & Comparable<N>> implements RevisionMetadata<N> {
 
 	private final Object entity;
 	private final Lazy<Optional<N>> revisionNumber;
-	private final Lazy<Optional<LocalDateTime>> revisionDate;
+	private final Lazy<Optional<Object>> revisionDate;
 
 	/**
 	 * Creates a new {@link AnnotationRevisionMetadata} inspecting the given entity for the given annotations. If no
@@ -69,7 +72,7 @@ public class AnnotationRevisionMetadata<N extends Number & Comparable<N>> implem
 	 * @see org.springframework.data.history.RevisionMetadata#getRevisionDate()
 	 */
 	public Optional<LocalDateTime> getRevisionDate() {
-		return revisionDate.get();
+		return revisionDate.get().map(AnnotationRevisionMetadata::convertToLocalDateTime);
 	}
 
 	/*
@@ -90,4 +93,30 @@ public class AnnotationRevisionMetadata<N extends Number & Comparable<N>> implem
 			return Optional.ofNullable(callback.getValue(entity));
 		});
 	}
+
+	private static LocalDateTime convertToLocalDateTime(Object timestamp) {
+
+		if (timestamp instanceof LocalDateTime) {
+			return (LocalDateTime) timestamp;
+		}
+
+		return LocalDateTime.ofInstant(convertToInstant(timestamp), ZoneOffset.systemDefault());
+	}
+
+	private static Instant convertToInstant(Object timestamp) {
+
+		if (timestamp instanceof Instant) {
+			return (Instant) timestamp;
+		}
+
+		if (timestamp instanceof LocalDateTime) {
+			return ((LocalDateTime) timestamp).atZone(ZoneOffset.systemDefault()).toInstant();
+		}
+
+		if (timestamp instanceof Long) {
+			return Instant.ofEpochMilli((Long) timestamp);
+		}
+
+		throw new IllegalArgumentException(String.format("Can't convert %s to Instant!", timestamp));
+	}
 }

src/test/java/org/springframework/data/history/AnnotationRevisionMetadataUnitTests.java

@@ -17,19 +17,25 @@ package org.springframework.data.history;
 
 import static org.assertj.core.api.Assertions.*;
 
+import java.time.Instant;
 import java.time.LocalDateTime;
+import java.time.ZoneOffset;
 
+import org.assertj.core.api.SoftAssertions;
 import org.junit.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.annotation.Reference;
 
 /**
  * Unit tests for {@link AnnotationRevisionMetadata}.
- * 
+ *
  * @author Oliver Gierke
+ * @author Jens Schauder
  */
 public class AnnotationRevisionMetadataUnitTests {
 
+	SoftAssertions softly = new SoftAssertions();
+
 	@Test // DATACMNS-1173
 	public void exposesNoInformationOnEmptyProbe() {
 
@@ -70,7 +76,39 @@ public class AnnotationRevisionMetadataUnitTests {
 		assertThat(metadata.getRequiredRevisionDate()).isEqualTo(sample.revisionDate);
 	}
 
-	private static RevisionMetadata<Long> getMetadata(Sample sample) {
+	@Test // DATACMNS-1251
+	public void exposesRevisionDateForInstant() {
+
+		SampleWithInstant sample = new SampleWithInstant();
+		sample.revisionInstant = Instant.now();
+		LocalDateTime expectedLocalDateTime = LocalDateTime.ofInstant(sample.revisionInstant, ZoneOffset.systemDefault());
+
+		RevisionMetadata<Long> metadata = getMetadata(sample);
+
+		softly.assertThat(metadata.getRevisionDate()).hasValue(expectedLocalDateTime);
+		softly.assertThat(metadata.getRequiredRevisionDate()).isEqualTo(expectedLocalDateTime);
+
+		softly.assertAll();
+	}
+
+	@Test // DATACMNS-1290
+	public void exposesRevisionDateForLong() {
+
+		SampleWithLong sample = new SampleWithLong();
+		sample.revisionLong = 4711L;
+
+		Instant expectedInstant = Instant.ofEpochMilli(sample.revisionLong);
+		LocalDateTime expectedLocalDateTime = LocalDateTime.ofInstant(expectedInstant, ZoneOffset.systemDefault());
+
+		RevisionMetadata<Long> metadata = getMetadata(sample);
+
+		softly.assertThat(metadata.getRevisionDate()).hasValue(expectedLocalDateTime);
+		softly.assertThat(metadata.getRequiredRevisionDate()).isEqualTo(expectedLocalDateTime);
+
+		softly.assertAll();
+	}
+
+	private static RevisionMetadata<Long> getMetadata(Object sample) {
 		return new AnnotationRevisionMetadata<>(sample, Autowired.class, Reference.class);
 	}
 
@@ -79,4 +117,16 @@ public class AnnotationRevisionMetadataUnitTests {
 		@Autowired Long revisionNumber;
 		@Reference LocalDateTime revisionDate;
 	}
+
+	static class SampleWithInstant {
+
+		@Autowired Long revisionNumber;
+		@Reference Instant revisionInstant;
+	}
+
+	static class SampleWithLong {
+
+		@Autowired Long revisionNumber;
+		@Reference long revisionLong;
+	}
 }