Use MongoDbFactory to create GridFsTemplate

Update MongoDataAutoConfiguration to use the MongoDbFactory when
creating GridFsTemplate.

Fixes gh-1295

Author: Phillip Webb

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoDataAutoConfiguration.java

@@ -26,12 +26,16 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.dao.DataAccessException;
+import org.springframework.dao.support.PersistenceExceptionTranslator;
 import org.springframework.data.mongodb.MongoDbFactory;
 import org.springframework.data.mongodb.core.MongoTemplate;
 import org.springframework.data.mongodb.core.SimpleMongoDbFactory;
 import org.springframework.data.mongodb.gridfs.GridFsTemplate;
+import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
+import com.mongodb.DB;
 import com.mongodb.Mongo;
 
 /**
@@ -73,11 +77,49 @@ public MongoTemplate mongoTemplate(MongoDbFactory mongoDbFactory)
 
 	@Bean
 	@ConditionalOnMissingBean
-	public GridFsTemplate gridFsTemplate(Mongo mongo, MongoTemplate mongoTemplate) {
-		String db = StringUtils.hasText(this.properties.getGridFsDatabase()) ? this.properties
-				.getGridFsDatabase() : this.properties.getMongoClientDatabase();
-		return new GridFsTemplate(new SimpleMongoDbFactory(mongo, db),
-				mongoTemplate.getConverter());
+	public GridFsTemplate gridFsTemplate(MongoDbFactory mongoDbFactory,
+			MongoTemplate mongoTemplate) {
+		return new GridFsTemplate(new GridFsMongoDbFactory(mongoDbFactory,
+				this.properties), mongoTemplate.getConverter());
+	}
+
+	/**
+	 * {@link MongoDbFactory} decorator to respect
+	 * {@link MongoProperties#getGridFsDatabase()} if set.
+	 */
+	private static class GridFsMongoDbFactory implements MongoDbFactory {
+
+		private final MongoDbFactory mongoDbFactory;
+
+		private final MongoProperties properties;
+
+		public GridFsMongoDbFactory(MongoDbFactory mongoDbFactory,
+				MongoProperties properties) {
+			Assert.notNull(mongoDbFactory, "MongoDbFactory must not be null");
+			Assert.notNull(properties, "Properties must not be null");
+			this.mongoDbFactory = mongoDbFactory;
+			this.properties = properties;
+		}
+
+		@Override
+		public DB getDb() throws DataAccessException {
+			String gridFsDatabase = this.properties.getGridFsDatabase();
+			if (StringUtils.hasText(gridFsDatabase)) {
+				return this.mongoDbFactory.getDb(gridFsDatabase);
+			}
+			return this.mongoDbFactory.getDb();
+		}
+
+		@Override
+		public DB getDb(String dbName) throws DataAccessException {
+			return this.mongoDbFactory.getDb(dbName);
+		}
+
+		@Override
+		public PersistenceExceptionTranslator getExceptionTranslator() {
+			return this.mongoDbFactory.getExceptionTranslator();
+		}
+
 	}
 
 }