This is the main documentation for the gora-mongodb module. gora-mongodb module enables MongoDB backend support for Gora.
This module has been tested with MongoDB Server 2.4.x and 2.6.x series. It will connect to remote MongoDB server(s) using standard Java MongoDB Driver
Here is a following sample gora.properties file to enable MongoStore:
# MongoDBStore properties
gora.datastore.default=org.apache.gora.mongodb.store.MongoStore
gora.mongodb.override_hadoop_configuration=false
gora.mongodb.mapping.file=/gora-mongodb-mapping.xml
gora.mongodb.servers=localhost
gora.mongodb.db=sample
Description of supported properties:
| Property | Example value | Required ? | Description |
|---|---|---|---|
| gora.datastore.default | org.apache.gora.mongodb.store.MongoStore | Yes | Implementation of the persistent Java storage class for MongoDB |
| gora.mongodb.override_hadoop_configuration | false | No | If true, it will allow properties to be overriden by configuration coming from Hadoop |
| gora.mongodb.mapping.file | /gora-mongodb-mapping.xml | No | The XML mapping file to be used. If no value is used this defaults to gora-mongodb-mapping.xml |
| gora.mongodb.servers | localhost:27017 | Yes | This value should specify the host:port for a running MongoDB node. Multiple values have to be separated by a coma character. |
| gora.mongodb.db | mytestdatabase | Yes | This value should specify the database for storage of documents. |
| gora.mongodb.login | login | No | Login that will be used to authenticate against MongoDB server. If blank, driver won't try authentication. |
| gora.mongodb.secret | password | No | Secret that will be used to authenticate against MongoDB server. |
| gora.mongodb.authentication.type | SCRAM-SHA-1 | No | Authentication mechanism type that will be used to authenticate against MongoDB server. |
You should then create a gora-mongodb-mapping.xml which will describe how you want to
store each of your Gora persistent objects:
<gora-otd>
<class name="org.apache.gora.examples.generated.Employee" keyClass="java.lang.String" document="employees">
<field name="name" docfield="name" type="string"/>
<field name="dateOfBirth" docfield="dateOfBirth" type="int64"/>
<field name="ssn" docfield="ssn" type="string"/>
<field name="salary" docfield="salary" type="int32"/>
<field name="boss" docfield="boss" type="document"/>
<field name="webpage" docfield="webpage" type="document"/>
</class>
</gora-otd>
Each class element specifying persistent fields which values should map to. This element contains;
a parameter containing the Persistent class name e.g. org.apache.gora.examples.generated.Employee,
a parameter containing the keyClass e.g. java.lang.String which specifies the keys which map to the field values,
a parameter containing the MongoDB collection e.g. employees which will be used to persist each Gora object,
finally a child element(s) field which represent all fields which are to be persisted into MongoDB. These need to be configured such that they receive the following;
a name attribute e.g. (name, dateOfBirth, ssn and salary respectively) which map to Gora field name,
a docfield attribute containing the field's name in mapped Mongo document,
a type attribute which allow transformation of Gora types into native MongoDB types. MongoDB use BSON is a binary serialization format to store documents and make remote procedure calls.
Description of supported type values:
| Type value | Description |
|---|---|
| BINARY | Store as binary data |
| BOOLEAN | Store as boolean value |
| INT32 | Store as signed 32-bit integer |
| INT64 | Store as signed 64-bit integer |
| DOUBLE | Store as floating point |
| STRING | Store as UTF-8 string |
| DATE | Store as UTC datetime (ISODate) |
| LIST | Store as Array |
| DOCUMENT | Store as embedded document |
| OBJECTID | Store as ObjectId (12-byte) |