DATAMONGO-2021 - Polishing.

Adapt getResources(…) to use the file id and no longer the file name when opening a download stream. Add author tag. Add test to verify content retrieval by identity.

Original pull request: #581.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/gridfs/GridFsTemplate.java

@@ -52,6 +52,7 @@ import com.mongodb.client.gridfs.model.GridFSUploadOptions;
  * @author Christoph Strobl
  * @author Mark Paluch
  * @author Hartmut Lang
+ * @author Niklas Helge Hanft
  */
 public class GridFsTemplate implements GridFsOperations, ResourcePatternResolver {
 
@@ -228,7 +229,8 @@ public class GridFsTemplate implements GridFsOperations, ResourcePatternResolver
 	 */
 	public GridFsResource getResource(String location) {
 
-		return Optional.ofNullable(findOne(query(whereFilename().is(location)))).map(this::getResource)
+		return Optional.ofNullable(findOne(query(whereFilename().is(location)))) //
+				.map(this::getResource) //
 				.orElseGet(() -> GridFsResource.absent(location));
 	}
 
@@ -261,7 +263,7 @@ public class GridFsTemplate implements GridFsOperations, ResourcePatternResolver
 			List<GridFsResource> resources = new ArrayList<>();
 
 			for (GridFSFile file : files) {
-				resources.add(new GridFsResource(file, getGridFs().openDownloadStream(file.getFilename())));
+				resources.add(getResource(file));
 			}
 
 			return resources.toArray(new GridFsResource[0]);

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/gridfs/GridFsTemplateIntegrationTests.java

@@ -22,7 +22,10 @@ import static org.springframework.data.mongodb.gridfs.GridFsCriteria.*;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
 
 import org.bson.BsonObjectId;
 import org.bson.Document;
@@ -38,6 +41,7 @@ import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.util.StreamUtils;
 
 import com.mongodb.MongoGridFSException;
 import com.mongodb.client.gridfs.GridFSFindIterable;
@@ -51,6 +55,7 @@ import com.mongodb.client.gridfs.model.GridFSFile;
  * @author Thomas Darimont
  * @author Martin Baumgartner
  * @author Hartmut Lang
+ * @author Mark Paluch
  */
 @RunWith(SpringJUnit4ClassRunner.class)
 @ContextConfiguration("classpath:gridfs/gridfs.xml")
@@ -239,6 +244,27 @@ public class GridFsTemplateIntegrationTests {
 		assertThat(((BsonObjectId) result.getId()).getValue()).isEqualTo(reference);
 	}
 
+	@Test // DATAMONGO-2021
+	public void getResourceShouldRetrieveContentByIdentity() throws IOException {
+
+		ClassPathResource secondResource = new ClassPathResource("gridfs/another-resource.xml");
+
+		ObjectId reference1 = operations.store(resource.getInputStream(), "foo.xml");
+		ObjectId reference2 = operations.store(secondResource.getInputStream(), "foo.xml");
+
+		Map<ObjectId, Resource> fixture = new LinkedHashMap<>();
+		fixture.put(reference1, resource);
+		fixture.put(reference2, secondResource);
+
+		for (Entry<ObjectId, Resource> entry : fixture.entrySet()) {
+
+			GridFsResource fsFile = operations.getResource(operations.findOne(query(where("_id").is(entry.getKey()))));
+			byte[] content = StreamUtils.copyToByteArray(fsFile.getInputStream());
+
+			assertThat(content).isEqualTo(StreamUtils.copyToByteArray(entry.getValue().getInputStream()));
+		}
+	}
+
 	class Metadata {
 		String version;
 	}

spring-data-mongodb/src/test/resources/gridfs/another-resource.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<empty/>