Additional coordination of externally-supplied MongoClient

flyway-core/src/main/java/org/flywaydb/core/MongoFlyway.java

@@ -669,14 +669,35 @@ public void setTargetAsString(String target) {
 	 *
      * Providing a MongoClient through this method will override the client created by using
      * the mongo uri. Use this method to retain the control over MongoClient instance.
+	 *
+	 * The databaseName will be supplied from a flyway.mongoUri property.
      *
 	 * @param client The MongoClient to use. Must have the necessary privileges to execute ddl.
 	 */
 	public void setMongoClient(MongoClient client) {
+		setMongoClient(client, null);
+	}
+
+	/**
+	 * Sets the MongoClient to use. Must have the necessary privileges to execute ddl.
+	 *
+	 * Providing a MongoClient through this method will override the client created by using
+	 * the mongo uri. Use this method to retain the control over MongoClient instance.
+	 *
+	 * @param client The MongoClient to use. Must have the necessary privileges to execute ddl.
+	 */
+	public void setMongoClient(MongoClient client, String databaseName) {
+		if (this.client != null) {
+			this.client.close();
+		}
+		if (databaseName != null) {
+			this.databaseName = databaseName;
+		}
 		this.client = client;
 		createdMongoClient = false;
 	}
 
+
 	/**
 	 * Sets the MongoClientURI to use.
 	 *
@@ -685,13 +706,15 @@ public void setMongoClient(MongoClient client) {
 	 * @param uri   MongoClient URI used to connect to a MongoDB database server.
 	 */
 	public void setMongoClientUri(String uri) {
-        MongoClientURI mongoUri = new MongoClientURI(uri);
-        this.databaseName = mongoUri.getDatabase();
-        if (databaseName == null) {
-            throw new FlywayException("Cannot find database from Mongo URI!");
-        }
-        this.client = new MongoClient(mongoUri);
-        createdMongoClient = true;
+        if (client == null) {
+			MongoClientURI mongoUri = new MongoClientURI(uri);
+			this.client = new MongoClient(mongoUri);
+			createdMongoClient = true;
+			this.databaseName = mongoUri.getDatabase();
+			if (databaseName == null) {
+				throw new FlywayException("Cannot find database from Mongo URI!");
+			}
+		}
 	}
 
 	/**
@@ -1046,7 +1069,8 @@ public void configure(Properties properties) {
 		if (StringUtils.hasText(uriProp)) {
 			setMongoClientUri(uriProp);
 		} else {
-			LOG.warn("Incomplete MongoDB configuration! flyway.mongoUri must be set.");
+			LOG.warn("Incomplete MongoDB configuration! flyway.mongoUri must be set unless you supply your" +
+					"own externally created mongoClient.");
 		}
 
 		String locationsProp = props.remove("flyway.locations");

flyway-core/src/test/java/org/flywaydb/core/MongoFlywayMediumTest.java

@@ -578,4 +578,22 @@ public void failed() {
             LogFactory.setLogCreator(null);
         }
     }
+
+    @Test
+    public void validExternalMongoClient() {
+
+        Properties props = new Properties();
+        props.setProperty("flyway.locations", "db.migrations.mongo");
+        props.setProperty("flyway.validateOnMigrate", "false");
+        // Do not set flywway.mongoUri
+        //props.setProperty("flyway.mongoUri", getMongoUri());
+
+        MongoFlyway flyway = new MongoFlyway();
+        flyway.configure(props);
+        // Set mongo client so that flyway does not close it.
+        flyway.setMongoClient(getMongoClient(), getDatabaseName());
+        flyway.migrate();
+
+
+    }
 }