DATAMONGO-2328 - Add missing target type conversions for field level type hints.

We now support Date to Long, Date to ObjectId, Script to String and other conversions for both reading and writing scenarios.

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/AbstractMongoConverter.java

@@ -15,8 +15,12 @@
  */
 package org.springframework.data.mongodb.core.convert;
 
+import static org.springframework.data.convert.ConverterBuilder.*;
+
 import java.math.BigInteger;
+import java.util.Date;
 
+import org.bson.types.Code;
 import org.bson.types.ObjectId;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.core.convert.ConversionService;
@@ -93,6 +97,21 @@ private void initializeConverters() {
 			conversionService.addConverter(BigIntegerToObjectIdConverter.INSTANCE);
 		}
 
+		if (!conversionService.canConvert(Date.class, Long.class)) {
+			conversionService.addConverter(writing(Date.class, Long.class, Date::getTime).getWritingConverter());
+		}
+
+		if (!conversionService.canConvert(Long.class, Date.class)) {
+			conversionService.addConverter(reading(Long.class, Date.class, Date::new).getReadingConverter());
+		}
+
+		if (!conversionService.canConvert(ObjectId.class, Date.class)) {
+
+			conversionService.addConverter(
+					reading(ObjectId.class, Date.class, objectId -> new Date(objectId.getTimestamp())).getReadingConverter());
+		}
+
+		conversionService.addConverter(reading(Code.class, String.class, Code::getCode).getReadingConverter());
 		conversions.registerConvertersIn(conversionService);
 	}
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java

@@ -40,7 +40,6 @@
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.junit.MockitoJUnitRunner;
-
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.beans.ConversionNotSupportedException;
 import org.springframework.beans.factory.annotation.Value;
@@ -1943,6 +1942,16 @@ public void mapsValueToExplicitTargetType() {
 		assertThat(target.get("script")).isEqualTo(new Code(source.script));
 	}
 
+	@Test // DATAMONGO-2328
+	public void readsScriptAsStringWhenAnnotatedWithFieldTargetType() {
+
+		String reference = "if (a > b) a else b";
+		WithExplicitTargetTypes target = converter.read(WithExplicitTargetTypes.class,
+				new org.bson.Document("script", new Code(reference)));
+
+		assertThat(target.script).isEqualTo(reference);
+	}
+
 	@Test // DATAMONGO-1849
 	public void mapsCollectionValueToExplicitTargetType() {
 
@@ -1968,6 +1977,96 @@ public void mapsBigDecimalToDecimal128WhenAnnotatedWithFieldTargetType() {
 		assertThat(target.get("bigDecimal")).isEqualTo(new Decimal128(source.bigDecimal));
 	}
 
+	@Test // DATAMONGO-2328
+	public void mapsDateToLongWhenAnnotatedWithFieldTargetType() {
+
+		WithExplicitTargetTypes source = new WithExplicitTargetTypes();
+		source.dateAsLong = new Date();
+
+		org.bson.Document target = new org.bson.Document();
+		converter.write(source, target);
+
+		assertThat(target.get("dateAsLong")).isEqualTo(source.dateAsLong.getTime());
+	}
+
+	@Test // DATAMONGO-2328
+	public void readsLongAsDateWhenAnnotatedWithFieldTargetType() {
+
+		Date reference = new Date();
+		WithExplicitTargetTypes target = converter.read(WithExplicitTargetTypes.class,
+				new org.bson.Document("dateAsLong", reference.getTime()));
+
+		assertThat(target.dateAsLong).isEqualTo(reference);
+	}
+
+	@Test // DATAMONGO-2328
+	public void mapsLongToDateWhenAnnotatedWithFieldTargetType() {
+
+		Date date = new Date();
+		WithExplicitTargetTypes source = new WithExplicitTargetTypes();
+		source.longAsDate = date.getTime();
+
+		org.bson.Document target = new org.bson.Document();
+		converter.write(source, target);
+
+		assertThat(target.get("longAsDate")).isEqualTo(date);
+	}
+
+	@Test // DATAMONGO-2328
+	public void readsDateAsLongWhenAnnotatedWithFieldTargetType() {
+
+		Date reference = new Date();
+		WithExplicitTargetTypes target = converter.read(WithExplicitTargetTypes.class,
+				new org.bson.Document("longAsDate", reference));
+
+		assertThat(target.longAsDate).isEqualTo(reference.getTime());
+	}
+
+	@Test // DATAMONGO-2328
+	public void mapsStringAsBooleanWhenAnnotatedWithFieldTargetType() {
+
+		WithExplicitTargetTypes source = new WithExplicitTargetTypes();
+		source.stringAsBoolean = "true";
+
+		org.bson.Document target = new org.bson.Document();
+		converter.write(source, target);
+
+		assertThat(target.get("stringAsBoolean")).isEqualTo(true);
+	}
+
+	@Test // DATAMONGO-2328
+	public void readsBooleanAsStringWhenAnnotatedWithFieldTargetType() {
+
+		WithExplicitTargetTypes target = converter.read(WithExplicitTargetTypes.class,
+				new org.bson.Document("stringAsBoolean", true));
+
+		assertThat(target.stringAsBoolean).isEqualTo("true");
+	}
+
+	@Test // DATAMONGO-2328
+	public void mapsDateAsObjectIdWhenAnnotatedWithFieldTargetType() {
+
+		WithExplicitTargetTypes source = new WithExplicitTargetTypes();
+		source.dateAsObjectId = new Date();
+
+		org.bson.Document target = new org.bson.Document();
+		converter.write(source, target);
+
+		// need to compare the the timestamp as ObjectId has an internal counter
+		assertThat(target.get("dateAsObjectId", ObjectId.class).getTimestamp())
+				.isEqualTo(new ObjectId(source.dateAsObjectId).getTimestamp());
+	}
+
+	@Test // DATAMONGO-2328
+	public void readsObjectIdAsDateWhenAnnotatedWithFieldTargetType() {
+
+		ObjectId reference = new ObjectId();
+		WithExplicitTargetTypes target = converter.read(WithExplicitTargetTypes.class,
+				new org.bson.Document("dateAsObjectId", reference));
+
+		assertThat(target.dateAsObjectId).isEqualTo(new Date(reference.getTimestamp()));
+	}
+
 	static class GenericType<T> {
 		T content;
 	}
@@ -1987,9 +2086,7 @@ void method() {}
 		},
 		SECOND {
 			@Override
-			void method() {
-
-			}
+			void method() {}
 		};
 
 		abstract void method();
@@ -2416,7 +2513,20 @@ static class WithExplicitTargetTypes {
 		@Field(targetType = FieldType.SCRIPT) //
 		List<String> scripts;
 
-		@Field(targetType = FieldType.DECIMAL128) BigDecimal bigDecimal;
+		@Field(targetType = FieldType.DECIMAL128) //
+		BigDecimal bigDecimal;
+
+		@Field(targetType = FieldType.INT64) //
+		Date dateAsLong;
+
+		@Field(targetType = FieldType.DATE_TIME) //
+		Long longAsDate;
+
+		@Field(targetType = FieldType.BOOLEAN) //
+		String stringAsBoolean;
+
+		@Field(targetType = FieldType.OBJECT_ID) //
+		Date dateAsObjectId;
 	}
 
 }