DATAMONGO-2392 - Fix handling in ReactiveGridFsTemplate of GridFS files with custom id type.

Original pull request: #796.

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

@@ -222,7 +222,7 @@ public class ReactiveGridFsTemplate extends GridFsOperationsSupport implements R
 
 		return Mono.fromSupplier(() -> {
 
-			GridFSDownloadStream stream = getGridFs().openDownloadStream(file.getObjectId());
+			GridFSDownloadStream stream = getGridFs().openDownloadStream(file.getId());
 
 			return new ReactiveGridFsResource(file, BinaryStreamAdapters.toPublisher(stream, dataBufferFactory));
 		});

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

@@ -0,0 +1,74 @@
+package org.springframework.data.mongodb.gridfs;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.data.mongodb.core.query.Criteria.where;
+import static org.springframework.data.mongodb.core.query.Query.query;
+
+import java.io.IOException;
+
+import com.mongodb.DB;
+import com.mongodb.MongoClient;
+import com.mongodb.gridfs.GridFS;
+import com.mongodb.gridfs.GridFSInputFile;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.Resource;
+import org.springframework.core.io.buffer.DataBufferUtils;
+import org.springframework.data.mongodb.core.SimpleMongoDbFactory;
+import org.springframework.data.mongodb.core.query.Query;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.util.StreamUtils;
+import reactor.test.StepVerifier;
+
+/**
+ * Integration tests for {@link ReactiveGridFsTemplate} in combination with the deprecated GridFs.
+ *
+ * @author Nick Stolwijk
+ */
+@RunWith(SpringRunner.class)
+@ContextConfiguration({"classpath:gridfs/reactive-gridfs.xml"})
+public class ReactiveGridFsTemplateWithOldGridFsTests {
+
+    Resource resource = new ClassPathResource("gridfs/gridfs.xml");
+
+    @Autowired ReactiveGridFsOperations operations;
+
+    @Autowired SimpleMongoDbFactory mongoClient;
+    @Before
+    public void setUp() {
+
+        operations.delete(new Query()) //
+                .as(StepVerifier::create) //
+                .verifyComplete();
+    }
+
+    @Test // DATAMONGO-2392
+    public void storeFileWithOldGridFsAndFindItWithReactiveGridFsOperations() throws IOException {
+        byte[] content = StreamUtils.copyToByteArray(resource.getInputStream());
+        String reference = "1af52e25-76b7-4e34-8618-9baa183c9112";
+
+        GridFS fs = new GridFS(mongoClient.getLegacyDb());
+        GridFSInputFile in = fs.createFile(resource.getInputStream(), "gridfs.xml");
+
+        in.put("_id", reference);
+        in.put("contentType", "application/octet-stream");
+        in.save();
+
+        operations.findOne(query(where("_id").is(reference))).flatMap(operations::getResource)
+                .flatMapMany(ReactiveGridFsResource::getDownloadStream) //
+                .transform(DataBufferUtils::join) //
+                .as(StepVerifier::create) //
+                .consumeNextWith(dataBuffer -> {
+
+                    byte[] actual = new byte[dataBuffer.readableByteCount()];
+                    dataBuffer.read(actual);
+
+                    assertThat(actual).isEqualTo(content);
+                }) //
+                .verifyComplete();
+    }
+}

spring-data-mongodb/src/test/resources/gridfs/reactive-gridfs.xml

@@ -3,13 +3,13 @@
 	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:util="http://www.springframework.org/schema/util"
 	   xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/util https://www.springframework.org/schema/util/spring-util.xsd">
 
-	<bean id="mongoClient" class="org.springframework.data.mongodb.core.ReactiveMongoClientFactoryBean">
+	<bean id="reactiveMongoClient" class="org.springframework.data.mongodb.core.ReactiveMongoClientFactoryBean">
 		<property name="host" value="127.0.0.1"/>
 		<property name="port" value="27017"/>
 	</bean>
 
 	<bean id="reactiveMongoDbFactory" class="org.springframework.data.mongodb.core.SimpleReactiveMongoDatabaseFactory">
-		<constructor-arg name="mongoClient" ref="mongoClient"/>
+		<constructor-arg name="mongoClient" ref="reactiveMongoClient" type="com.mongodb.reactivestreams.client.MongoClient"/>
 		<constructor-arg name="databaseName" value="reactive_gridfs"/>
 	</bean>
 
@@ -27,4 +27,13 @@
 		<constructor-arg ref="converter"/>
 	</bean>
 
+	<bean id="mongoClient" class="org.springframework.data.mongodb.core.MongoClientFactoryBean">
+		<property name="host" value="127.0.0.1"/>
+		<property name="port" value="27017"/>
+	</bean>
+
+	<bean id="mongoDbFactory" class="org.springframework.data.mongodb.core.SimpleMongoDbFactory">
+		<constructor-arg name="mongoClient" ref="mongoClient"/>
+		<constructor-arg name="databaseName" value="reactive_gridfs"/>
+	</bean>
 </beans>