jovikao/mongo-java-server

Stub implementation of MongoDB in Java, that speaks the wire protocol.

MongoDB Java Server

Stub implementation of the core MongoDB server in Java. The MongoDB Wire Protocol is implemented with Netty. Different backends are possible and can be easily extended.

In-Memory backend

The in-memory backend is the default, such that mongo-java-server can be used as stub in unit tests. It does not support all features of the original MongoDB, and probably never will.

Ideas for other backends

Faulty backend

A faulty backend could randomly fail queries or cause timeouts. This could be used to test the client for error resilience.

Fuzzy backend

Fuzzing the wire protocol could be used to check the robustness of client drivers.

Usage

Add the following Maven dependency to your project:

<dependency>
	<groupId>de.bwaldvogel</groupId>
	<artifactId>mongo-java-server</artifactId>
	<version>1.1.1</version>
</dependency>

Unit test example

public class SimpleTest {

	private DBCollection collection;
	private MongoClient client;
	private MongoServer server;

	@Before
	public void setUp() {
		server = new MongoServer(new MemoryBackend());

		// bind on a random local port
		InetSocketAddress serverAddress = server.bind();

		client = new MongoClient(new ServerAddress(serverAddress));
		collection = client.getDB("testdb").getCollection("testcollection");
	}

	@After
	public void tearDown() {
		client.close();
		server.shutdownNow();
	}

	@Test
	public void testSimpleInsertQuery() throws Exception {
		assertEquals(0, collection.count());

		// creates the database and collection in memory and insert the object
		DBObject obj = new BasicDBObject("_id", 1).append("key", "value");
		collection.insert(obj);

		assertEquals(1, collection.count());
		assertEquals(obj, collection.findOne());
	}

}

Related Work

• jmockmongo

  • shares the basic idea of implementing the wire protocol with Netty
  • focus on in-memory backend for unit testing

• jongo

  • focus on unit testing
  • no wire protocol implementation
  • intercepts the java mongo driver
  • currently used in nosql-unit