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.
Add the following Maven dependency to your project:
<dependency>
<groupId>de.bwaldvogel</groupId>
<artifactId>mongo-java-server</artifactId>
<version>1.7.0</version>
</dependency>The in-memory backend is the default, such that mongo-java-server can be used as stub in unit tests. It supports the basic CRUD operations. However, not all features are implemented, such as full-text search or map/reduce.
public class SimpleTest {
private MongoCollection<Document> 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.getDatabase("testdb").getCollection("testcollection");
}
@After
public void tearDown() {
client.close();
server.shutdown();
}
@Test
public void testSimpleInsertQuery() throws Exception {
assertEquals(0, collection.count());
// creates the database and collection in memory and insert the object
Document obj = new Document("_id", 1).append("key", "value");
collection.insertOne(obj);
assertEquals(1, collection.count());
assertEquals(obj, collection.find().first());
}
}The H2 MVStore backend connects the server to a MVStore that
can either be in-memory or on-disk.
<dependency>
<groupId>de.bwaldvogel</groupId>
<artifactId>mongo-java-server-h2-backend</artifactId>
<version>1.7.0</version>
</dependency>public class Application {
public static void main(String[] args) throws Exception {
MongoServer server = new MongoServer(new H2Backend("database.mv"));
server.bind("localhost", 27017);
}
}The PostgreSQL backend connects the server to a database in a running PostgreSQL 9.5+ instance. Each MongoDB database is mapped to a schema in Postgres and each MongoDB collection is stored as a table.
<dependency>
<groupId>de.bwaldvogel</groupId>
<artifactId>mongo-java-server-postgresql-backend</artifactId>
<version>1.7.0</version>
</dependency>public class Application {
public static void main(String[] args) throws Exception {
DataSource dataSource = new org.postgresql.jdbc3.Jdbc3PoolingDataSource();
dataSource.setDatabaseName(…);
dataSource.setUser(…);
dataSource.setPassword(…);
MongoServer server = new MongoServer(new PostgresqlBackend(dataSource));
server.bind("localhost", 27017);
}
}A faulty backend could randomly fail queries or cause timeouts. This could be used to test the client for error resilience.
Fuzzing the wire protocol could be used to check the robustness of client drivers.
-
- shares the basic idea of implementing the wire protocol with Netty
- focus on in-memory backend for unit testing
-
- focus on unit testing
- no wire protocol implementation
- intercepts the java mongo driver
- currently used in nosql-unit