Chapter 229. MongoDB GridFS Component
Available as of Camel version 2.18
Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-mongodb-gridfs</artifactId>
<version>x.y.z</version>
<!-- use the same version as your Camel core version -->
</dependency>229.1. URI format
mongodb-gridfs:connectionBean?database=databaseName&bucket=bucketName[&moreOptions...]
229.2. MongoDB GridFS options
The MongoDB GridFS component has no options.
The MongoDB GridFS endpoint is configured using URI syntax:
mongodb-gridfs:connectionBean
with the following path and query parameters:
229.2.1. Path Parameters (1 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| connectionBean | Required Name of com.mongodb.Mongo to use. | String |
229.2.2. Query Parameters (17 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| bucket (common) | Sets the name of the GridFS bucket within the database. Default is fs. | fs | String |
| database (common) | Required Sets the name of the MongoDB database to target | String | |
| readPreference (common) | Sets a MongoDB ReadPreference on the Mongo connection. Read preferences set directly on the connection will be overridden by this setting. The com.mongodb.ReadPreference#valueOf(String) utility method is used to resolve the passed readPreference value. Some examples for the possible values are nearest, primary or secondary etc. | ReadPreference | |
| writeConcern (common) | Set the WriteConcern for write operations on MongoDB using the standard ones. Resolved from the fields of the WriteConcern class by calling the WriteConcern#valueOf(String) method. | WriteConcern | |
| writeConcernRef (common) | Set the WriteConcern for write operations on MongoDB, passing in the bean ref to a custom WriteConcern which exists in the Registry. You can also use standard WriteConcerns by passing in their key. See the link #setWriteConcern(String) setWriteConcern method. | WriteConcern | |
| bridgeErrorHandler (consumer) | Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. | false | boolean |
| delay (consumer) | Sets the delay between polls within the Consumer. Default is 500ms | 500 | long |
| fileAttributeName (consumer) | If the QueryType uses a FileAttribute, this sets the name of the attribute that is used. Default is camel-processed. | camel-processed | String |
| initialDelay (consumer) | Sets the initialDelay before the consumer will start polling. Default is 1000ms | 1000 | long |
| persistentTSCollection (consumer) | If the QueryType uses a persistent timestamp, this sets the name of the collection within the DB to store the timestamp. | camel-timestamps | String |
| persistentTSObject (consumer) | If the QueryType uses a persistent timestamp, this is the ID of the object in the collection to store the timestamp. | camel-timestamp | String |
| query (consumer) | Additional query parameters (in JSON) that are used to configure the query used for finding files in the GridFsConsumer | String | |
| queryStrategy (consumer) | Sets the QueryStrategy that is used for polling for new files. Default is Timestamp | TimeStamp | QueryStrategy |
| exceptionHandler (consumer) | To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored. | ExceptionHandler | |
| exchangePattern (consumer) | Sets the exchange pattern when the consumer creates an exchange. | ExchangePattern | |
| operation (producer) | Sets the operation this endpoint will execute against GridRS. | String | |
| synchronous (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean |
229.3. Spring Boot Auto-Configuration
The component supports 2 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| camel.component.mongodb-gridfs.enabled | Enable mongodb-gridfs component | true | Boolean |
| camel.component.mongodb-gridfs.resolve-property-placeholders | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | Boolean |
229.4. Configuration of database in Spring XML
The following Spring XML creates a bean defining the connection to a MongoDB instance.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="mongoBean" class="com.mongodb.Mongo">
<constructor-arg name="host" value="${mongodb.host}" />
<constructor-arg name="port" value="${mongodb.port}" />
</bean>
</beans>229.5. Sample route
The following route defined in Spring XML executes the operation findOne on a collection.
Get a file from GridFS
<route>
<from uri="direct:start" />
<!-- using bean 'mongoBean' defined above -->
<to uri="mongodb-gridfs:mongoBean?database=${mongodb.database}&operation=findOne" />
<to uri="direct:result" />
</route>
229.6. GridFS operations - producer endpoint
229.6.1. count
Returns the total number of file in the collection, returning an Integer as the OUT message body.
// from("direct:count").to("mongodb-gridfs?database=tickets&operation=count");
Integer result = template.requestBodyAndHeader("direct:count", "irrelevantBody");
assertTrue("Result is not of type Long", result instanceof Integer);You can provide a filename header to provide a count of files matching that filename.
Map<String, Object> headers = new HashMap<String, Object>();
headers.put(Exchange.FILE_NAME, "filename.txt");
Integer count = template.requestBodyAndHeaders("direct:count", query, headers);229.6.2. listAll
Returns an Reader that lists all the filenames and their IDs in a tab separated stream.
// from("direct:listAll").to("mongodb-gridfs?database=tickets&operation=listAll");
Reader result = template.requestBodyAndHeader("direct:listAll", "irrelevantBody");
filename1.txt 1252314321
filename2.txt 2897651254
229.6.3. findOne
Finds a file in the GridFS system and sets the body to an InputStream of the content. Also provides the metadata has headers. It uses Exchange.FILE_NAME from the incoming headers to determine the file to find.
// from("direct:findOne").to("mongodb-gridfs?database=tickets&operation=findOne");
Map<String, Object> headers = new HashMap<String, Object>();
headers.put(Exchange.FILE_NAME, "filename.txt");
InputStream result = template.requestBodyAndHeaders("direct:findOne", "irrelevantBody", headers);
229.6.4. create
Creates a new file in the GridFs database. It uses the Exchange.FILE_NAME from the incoming headers for the name and the body contents (as an InputStream) as the content.
// from("direct:create").to("mongodb-gridfs?database=tickets&operation=create");
Map<String, Object> headers = new HashMap<String, Object>();
headers.put(Exchange.FILE_NAME, "filename.txt");
InputStream stream = ... the data for the file ...
template.requestBodyAndHeaders("direct:create", stream, headers);229.6.5. remove
Removes a file from the GridFS database.
// from("direct:remove").to("mongodb-gridfs?database=tickets&operation=remove");
Map<String, Object> headers = new HashMap<String, Object>();
headers.put(Exchange.FILE_NAME, "filename.txt");
template.requestBodyAndHeaders("direct:remove", "", headers);229.7. GridFS Consumer
See also
- MongoDB website
- NoSQL Wikipedia article
- MongoDB Java driver API docs - current version * Unit tests for more examples of usage
