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A Vert.x client allowing applications to interact with a MongoDB instance, whether that’s saving, retrieving, searching, or deleting documents.

Mongo is a great match for persisting data in a Vert.x application as it natively handles JSON (BSON) documents.

Features

  • Completely non-blocking

  • Custom codec to support fast serialization to/from Vert.x JSON

  • Supports a majority of the configuration options from the MongoDB Java Driver

This client is based on the MongoDB Async Driver.

Using Vert.x MongoDB Client

To use this project, add the following dependency to the dependencies section of your build descriptor:

  • Maven (in your pom.xml):

<dependency>
  <groupId>io.vertx</groupId>
  <artifactId>vertx-mongo-client</artifactId>
  <version>3.4.1</version>
</dependency>
  • Gradle (in your build.gradle file):

compile 'io.vertx:vertx-mongo-client:3.4.1'

Creating a client

You can create a client in several ways:

Using the default shared pool

In most cases you will want to share a pool between different client instances.

E.g. you scale your application by deploying multiple instances of your verticle and you want each verticle instance to share the same pool so you don’t end up with multiple pools

The simplest way to do this is as follows:

var MongoClient = require("vertx-mongo-js/mongo_client");

var client = MongoClient.createShared(vertx, config);

The first call to MongoClient.createShared will actually create the pool, and the specified config will be used.

Subsequent calls will return a new client instance that uses the same pool, so the configuration won’t be used.

Specifying a pool source name

You can create a client specifying a pool source name as follows

var MongoClient = require("vertx-mongo-js/mongo_client");

var client = MongoClient.createShared(vertx, config, "MyPoolName");

If different clients are created using the same Vert.x instance and specifying the same pool name, they will share the same pool.

The first call to MongoClient.createShared will actually create the pool, and the specified config will be used.

Subsequent calls will return a new client instance that uses the same pool, so the configuration won’t be used.

Use this way of creating if you wish different groups of clients to have different pools, e.g. they’re interacting with different databases.

Creating a client with a non shared data pool

In most cases you will want to share a pool between different client instances. However, it’s possible you want to create a client instance that doesn’t share its pool with any other client.

In that case you can use MongoClient.createNonShared.

var MongoClient = require("vertx-mongo-js/mongo_client");

var client = MongoClient.createNonShared(vertx, config);

This is equivalent to calling MongoClient.createShared with a unique pool name each time.

Using the API

The client API is represented by MongoClient.

Saving documents

To save a document you use save.

If the document has no _id field, it is inserted, otherwise, it is _upserted_. Upserted means it is inserted if it doesn’t already exist, otherwise it is updated.

If the document is inserted and has no id, then the id field generated will be returned to the result handler.

Here’s an example of saving a document and getting the id back

// Document has no id

var document = {
  "title" : "The Hobbit"
};

mongoClient.save("books", document, function (res, res_err) {

  if (res_err == null) {

    var id = res;
    console.log("Saved book with id " + id);

  } else {
    res_err.printStackTrace();
  }

});

And here’s an example of saving a document which already has an id.

// Document has an id already

var document = {
  "title" : "The Hobbit",
  "_id" : "123244"
};

mongoClient.save("books", document, function (res, res_err) {

  if (res_err == null) {

    // ...

  } else {
    res_err.printStackTrace();
  }

});

Inserting documents

To insert a document you use insert.

If the document is inserted and has no id, then the id field generated will be returned to the result handler.

// Document has an id already

var document = {
  "title" : "The Hobbit"
};

mongoClient.insert("books", document, function (res, res_err) {

  if (res_err == null) {

    var id = res;
    console.log("Inserted book with id " + id);

  } else {
    res_err.printStackTrace();
  }

});

If a document is inserted with an id, and a document with that id already eists, the insert will fail:

// Document has an id already

var document = {
  "title" : "The Hobbit",
  "_id" : "123244"
};

mongoClient.insert("books", document, function (res, res_err) {

  if (res_err == null) {

    //...

  } else {

    // Will fail if the book with that id already exists.
  }

});

Updating documents

To update a documents you use update.

This updates one or multiple documents in a collection. The json object that is passed in the update parameter must contain Update Operators and determines how the object is updated.

The json object specified in the query parameter determines which documents in the collection will be updated.

Here’s an example of updating a document in the books collection:

// Match any documents with title=The Hobbit
var query = {
  "title" : "The Hobbit"
};

// Set the author field
var update = {
  "$set" : {
    "author" : "J. R. R. Tolkien"
  }
};

mongoClient.update("books", query, update, function (res, res_err) {

  if (res_err == null) {

    console.log("Book updated !");

  } else {

    res_err.printStackTrace();
  }

});

To specify if the update should upsert or update multiple documents, use updateWithOptions and pass in an instance of UpdateOptions.

This has the following fields:

multi

set to true to update multiple documents

upsert

set to true to insert the document if the query doesn’t match

writeConcern

the write concern for this operation

// Match any documents with title=The Hobbit
var query = {
  "title" : "The Hobbit"
};

// Set the author field
var update = {
  "$set" : {
    "author" : "J. R. R. Tolkien"
  }
};

var options = {
  "multi" : true
};

mongoClient.updateWithOptions("books", query, update, options, function (res, res_err) {

  if (res_err == null) {

    console.log("Book updated !");

  } else {

    res_err.printStackTrace();
  }

});

Replacing documents

To replace documents you use replace.

This is similar to the update operation, however it does not take any update operators like update. Instead it replaces the entire document with the one provided.

Here’s an example of replacing a document in the books collection

var query = {
  "title" : "The Hobbit"
};

var replace = {
  "title" : "The Lord of the Rings",
  "author" : "J. R. R. Tolkien"
};

mongoClient.replace("books", query, replace, function (res, res_err) {

  if (res_err == null) {

    console.log("Book replaced !");

  } else {

    res_err.printStackTrace();

  }

});

Finding documents

To find documents you use find.

The query parameter is used to match the documents in the collection.

Here’s a simple example with an empty query that will match all books:

// empty query = match any
var query = {
};

mongoClient.find("books", query, function (res, res_err) {

  if (res_err == null) {

    Array.prototype.forEach.call(res, function(json) {

      console.log(JSON.stringify(json));

    });

  } else {

    res_err.printStackTrace();

  }

});

Here’s another example that will match all books by Tolkien:

// will match all Tolkien books
var query = {
  "author" : "J. R. R. Tolkien"
};

mongoClient.find("books", query, function (res, res_err) {

  if (res_err == null) {

    Array.prototype.forEach.call(res, function(json) {

      console.log(JSON.stringify(json));

    });

  } else {

    res_err.printStackTrace();

  }

});

The matching documents are returned as a list of json objects in the result handler.

To specify things like what fields to return, how many results to return, etc use findWithOptions and pass in the an instance of FindOptions.

This has the following fields:

fields

The fields to return in the results. Defaults to null, meaning all fields will be returned

sort

The fields to sort by. Defaults to null.

limit

The limit of the number of results to return. Default to -1, meaning all results will be returned.

skip

The number of documents to skip before returning the results. Defaults to 0.

// will match all Tolkien books
var query = {
  "author" : "J. R. R. Tolkien"
};

mongoClient.findBatch("book", query, function (res, res_err) {

  if (res_err == null) {

    if ((res === null || res === undefined)) {

      console.log("End of research");

    } else {

      console.log("Found doc: " + JSON.stringify(res));

    }

  } else {

    res_err.printStackTrace();

  }
});

The matching documents are returned unitary in the result handler.

Finding a single document

To find a single document you use findOne.

This works just like find but it returns just the first matching document.

Removing documents

To remove documents use removeDocuments.

The query parameter is used to match the documents in the collection to determine which ones to remove.

Here’s an example of removing all Tolkien books:

var query = {
  "author" : "J. R. R. Tolkien"
};

mongoClient.remove("books", query, function (res, res_err) {

  if (res_err == null) {

    console.log("Never much liked Tolkien stuff!");

  } else {

    res_err.printStackTrace();

  }
});

Removing a single document

To remove a single document you use removeDocument.

This works just like removeDocuments but it removes just the first matching document.

Counting documents

To count documents use count.

Here’s an example that counts the number of Tolkien books. The number is passed to the result handler.

var query = {
  "author" : "J. R. R. Tolkien"
};

mongoClient.count("books", query, function (res, res_err) {

  if (res_err == null) {

    var num = res;

  } else {

    res_err.printStackTrace();

  }
});

Managing MongoDB collections

All MongoDB documents are stored in collections.

To get a list of all collections you can use getCollections

mongoClient.getCollections(function (res, res_err) {

  if (res_err == null) {

    var collections = res;

  } else {

    res_err.printStackTrace();

  }
});

To create a new collection you can use createCollection

mongoClient.createCollection("mynewcollectionr", function (res, res_err) {

  if (res_err == null) {

    // Created ok!

  } else {

    res_err.printStackTrace();

  }
});

To drop a collection you can use dropCollection

Note
Dropping a collection will delete all documents within it!
mongoClient.dropCollection("mynewcollectionr", function (res, res_err) {

  if (res_err == null) {

    // Dropped ok!

  } else {

    res_err.printStackTrace();

  }
});

Running other MongoDB commands

You can run arbitrary MongoDB commands with runCommand.

Commands can be used to run more advanced mongoDB features, such as using MapReduce. For more information see the mongo docs for supported Commands.

Here’s an example of running an aggregate command. Note that the command name must be specified as a parameter and also be contained in the JSON that represents the command. This is because JSON is not ordered but BSON is ordered and MongoDB expects the first BSON entry to be the name of the command. In order for us to know which of the entries in the JSON is the command name it must be specified as a parameter.

var command = {
  "aggregate" : "collection_name",
  "pipeline" : [
  ]
};

mongoClient.runCommand("aggregate", command, function (res, res_err) {
  if (res_err == null) {
    var resArr = res.result;
    // etc
  } else {
    res_err.printStackTrace();
  }
});

MongoDB Extended JSON support

For now, only date, oid and binary types are supported (cf http://docs.mongodb.org/manual/reference/mongodb-extended-json )

Here’s an example of inserting a document with a date field

var document = {
  "title" : "The Hobbit",
  "publicationDate" : {
    "$date" : "1937-09-21T00:00:00+00:00"
  }
};

mongoService.save("publishedBooks", document, function (res, res_err) {

  if (res_err == null) {

    var id = res;

    mongoService.findOne("publishedBooks", {
      "_id" : id
    }, null, function (res2, res2_err) {
      if (res2_err == null) {

        console.log("To retrieve ISO-8601 date : " + res2.publicationDate.$date);

      } else {
        res2_err.printStackTrace();
      }
    });

  } else {
    res_err.printStackTrace();
  }

});

Here’s an example (in Java) of inserting a document with a binary field and reading it back

byte[] binaryObject = new byte[40];

JsonObject document = new JsonObject()
        .put("name", "Alan Turing")
        .put("binaryStuff", new JsonObject().put("$binary", binaryObject));

mongoService.save("smartPeople", document, res -> {

  if (res.succeeded()) {

    String id = res.result();

    mongoService.findOne("smartPeople", new JsonObject().put("_id", id), null, res2 -> {
      if(res2.succeeded()) {

        byte[] reconstitutedBinaryObject = res2.result().getJsonObject("binaryStuff").getBinary("$binary");
        //This could now be de-serialized into an object in real life
      } else {
        res2.cause().printStackTrace();
      }
    });

  } else {
    res.cause().printStackTrace();
  }

});

Here’s an example of inserting a base 64 encoded string, typing it as binary a binary field, and reading it back

//This could be a the byte contents of a pdf file, etc converted to base 64
var base64EncodedString = "a2FpbHVhIGlzIHRoZSAjMSBiZWFjaCBpbiB0aGUgd29ybGQ=";

var document = {
  "name" : "Alan Turing",
  "binaryStuff" : {
    "$binary" : base64EncodedString
  }
};

mongoService.save("smartPeople", document, function (res, res_err) {

  if (res_err == null) {

    var id = res;

    mongoService.findOne("smartPeople", {
      "_id" : id
    }, null, function (res2, res2_err) {
      if (res2_err == null) {

        var reconstitutedBase64EncodedString = res2.binaryStuff.$binary;
        //This could now converted back to bytes from the base 64 string
      } else {
        res2_err.printStackTrace();
      }
    });

  } else {
    res_err.printStackTrace();
  }

});

Here’s an example of inserting an object ID and reading it back

var individualId = new (Java.type("org.bson.types.ObjectId"))().toHexString();

var document = {
  "name" : "Stephen Hawking",
  "individualId" : {
    "$oid" : individualId
  }
};

mongoService.save("smartPeople", document, function (res, res_err) {

  if (res_err == null) {

    var id = res;

    mongoService.findOne("smartPeople", {
      "_id" : id
    }, null, function (res2, res2_err) {
      if (res2_err == null) {
        var reconstitutedIndividualId = res2.individualId.$oid;
      } else {
        res2_err.printStackTrace();
      }
    });

  } else {
    res_err.printStackTrace();
  }

});

Here’s an example of getting disting value

var document = {
  "title" : "The Hobbit"
};

mongoClient.save("books", document, function (res, res_err) {

  if (res_err == null) {

    mongoClient.distinct("books", "title", Java.type("java.lang.String").class.getName(), function (res2, res2_err) {
      console.log("Title is : " + res2[0]);
    });

  } else {
    res_err.printStackTrace();
  }

});

Here’s an example of getting distinct value in batch mode

var document = {
  "title" : "The Hobbit"
};

mongoClient.save("books", document, function (res, res_err) {

  if (res_err == null) {

    mongoClient.distinctBatch("books", "title", Java.type("java.lang.String").class.getName(), function (res2, res2_err) {
      console.log("Title is : " + res2.title);
    });

  } else {
    res_err.printStackTrace();
  }

});

Configuring the client

The client is configured with a json object.

The following configuration is supported by the mongo client:

db_name

Name of the database in the mongoDB instance to use. Defaults to default_db

useObjectId

Toggle this option to support persisting and retrieving ObjectId’s as strings. If true, hex-strings will be saved as native Mongodb ObjectId types in the document collection. This will allow the sorting of documents based on creation time. You can also derive the creation time from the hex-string using ObjectId::getDate(). Set to false for other types of your choosing. If set to false, or left to default, hex strings will be generated as the document _id if the _id is omitted from the document. Defaults to false.

The mongo client tries to support most options that are allowed by the driver. There are two ways to configure mongo for use by the driver, either by a connection string or by separate configuration options.

Note
If the connection string is used the mongo client will ignore any driver configuration options.
connection_string

The connection string the driver uses to create the client. E.g. mongodb://localhost:27017. For more information on the format of the connection string please consult the driver documentation.

Specific driver configuration options

{
  // Single Cluster Settings
  "host" : "127.0.0.1", // string
  "port" : 27017,      // int

  // Multiple Cluster Settings
  "hosts" : [
    {
      "host" : "cluster1", // string
      "port" : 27000       // int
    },
    {
      "host" : "cluster2", // string
      "port" : 28000       // int
    },
    ...
  ],
  "replicaSet" :  "foo",    // string
  "serverSelectionTimeoutMS" : 30000, // long

  // Connection Pool Settings
  "maxPoolSize" : 50,                // int
  "minPoolSize" : 25,                // int
  "maxIdleTimeMS" : 300000,          // long
  "maxLifeTimeMS" : 3600000,         // long
  "waitQueueMultiple"  : 10,         // int
  "waitQueueTimeoutMS" : 10000,      // long
  "maintenanceFrequencyMS" : 2000,   // long
  "maintenanceInitialDelayMS" : 500, // long

  // Credentials / Auth
  "username"   : "john",     // string
  "password"   : "passw0rd", // string
  "authSource" : "some.db"   // string
  // Auth mechanism
  "authMechanism"     : "GSSAPI",        // string
  "gssapiServiceName" : "myservicename", // string

  // Socket Settings
  "connectTimeoutMS" : 300000, // int
  "socketTimeoutMS"  : 100000, // int
  "sendBufferSize"    : 8192,  // int
  "receiveBufferSize" : 8192,  // int
  "keepAlive" : true           // boolean

  // Heartbeat socket settings
  "heartbeat.socket" : {
  "connectTimeoutMS" : 300000, // int
  "socketTimeoutMS"  : 100000, // int
  "sendBufferSize"    : 8192,  // int
  "receiveBufferSize" : 8192,  // int
  "keepAlive" : true           // boolean
  }

  // Server Settings
  "heartbeatFrequencyMS" :    1000 // long
  "minHeartbeatFrequencyMS" : 500 // long
}

Driver option descriptions

host

The host the mongoDB instance is running. Defaults to 127.0.0.1. This is ignored if hosts is specified

port

The port the mongoDB instance is listening on. Defaults to 27017. This is ignored if hosts is specified

hosts

An array representing the hosts and ports to support a mongoDB cluster (sharding / replication)

host

A host in the cluster

port

The port a host in the cluster is listening on

replicaSet

The name of the replica set, if the mongoDB instance is a member of a replica set

serverSelectionTimeoutMS

The time in milliseconds that the mongo driver will wait to select a server for an operation before raising an error.

maxPoolSize

The maximum number of connections in the connection pool. The default value is 100

minPoolSize

The minimum number of connections in the connection pool. The default value is 0

maxIdleTimeMS

The maximum idle time of a pooled connection. The default value is 0 which means there is no limit

maxLifeTimeMS

The maximum time a pooled connection can live for. The default value is 0 which means there is no limit

waitQueueMultiple

The maximum number of waiters for a connection to become available from the pool. Default value is 500

waitQueueTimeoutMS

The maximum time that a thread may wait for a connection to become available. Default value is 120000 (2 minutes)

maintenanceFrequencyMS

The time period between runs of the maintenance job. Default is 0.

maintenanceInitialDelayMS

The period of time to wait before running the first maintenance job on the connection pool. Default is 0.

username

The username to authenticate. Default is null (meaning no authentication required)

password

The password to use to authenticate.

authSource

The database name associated with the user’s credentials. Default value is the db_name value.

authMechanism

The authentication mechanism to use. See [Authentication](http://docs.mongodb.org/manual/core/authentication/) for more details.

gssapiServiceName

The Kerberos service name if GSSAPI is specified as the authMechanism.

connectTimeoutMS

The time in milliseconds to attempt a connection before timing out. Default is 10000 (10 seconds)

socketTimeoutMS

The time in milliseconds to attempt a send or receive on a socket before the attempt times out. Default is 0 meaning there is no timeout

sendBufferSize

Sets the send buffer size (SO_SNDBUF) for the socket. Default is 0, meaning it will use the OS default for this option.

receiveBufferSize

Sets the receive buffer size (SO_RCVBUF) for the socket. Default is 0, meaning it will use the OS default for this option.

keepAlive

Sets the keep alive (SO_KEEPALIVE) for the socket. Default is false

heartbeat.socket

Configures the socket settings for the cluster monitor of the MongoDB java driver.

heartbeatFrequencyMS

The frequency that the cluster monitor attempts to reach each server. Default is 5000 (5 seconds)

minHeartbeatFrequencyMS

The minimum heartbeat frequency. The default value is 1000 (1 second)

Note
Most of the default values listed above use the default values of the MongoDB Java Driver. Please consult the driver documentation for up to date information.