Camel MongoDB GridFS component
Available as of Camel 2.17
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>
URI format
gridfs:connectionBean?database=databaseName&bucket=bucketName[&moreOptions...]
Endpoint options
GridFS endpoints support the following options, depending on whether they are acting like a Producer or as a Consumer (options vary based on the consumer type too).
Name | Default Value | Description | Producer | Consumer |
---|---|---|---|---|
| none | Required. The name of the database to which this endpoint will be bound. All operations will be executed against this database. | ||
| fs | The name of the GridFS bucket within the Database. The default is the GridFS.DEFAULT_BUCKET value ("fs"). | ||
| create | The id of the operation this endpoint will execute. Pick from the following:
|
| |
query | none | Combined with the query strategy parameters to create the query used to search for new files. | ||
queryStrategy | TimeStamp | The strategy that is used to find new files. Can be one of:
| ||
persistentTSCollection | camel-timestamps | When using persistent timestamps, this is the Collection that the timestamp is stored into. | ||
persistenTSObject | camel-timestamp | When using persistent timestamps, this is the object ID for the timestamp object. Each consumer can have it's own timestamp ID stored in a common Collection | ||
fileAttributeName | camel-processed | When using FileAttribute, this is the name of the attribute that is used. When a file is about to be processed, the attribute is set to "processing" and then set to "done" when the file processing is done. | ||
delay | 500 (ms) | The delay between polling GridFS for new files | ||
initialDelay | 1000 (ms) | The initial delay before the first poll |
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>
Sample route
The following route defined in Spring XML executes the operation findOne on a collection.
<route> <from uri="direct:start" /> <!-- using bean 'mongoBean' defined above --> <to uri="gridfs:mongoBean?database=${mongodb.database}&operation=findOne" /> <to uri="direct:result" /> </route>
GridFS operations - producer endpoint
count
Returns the total number of file in the collection, returning an Integer as the OUT message body.
// from("direct:count").to("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);
listAll
Returns an Reader that lists all the filenames and their IDs in a tab separated stream.
// from("direct:listAll").to("gridfs?database=tickets&operation=listAll"); Reader result = template.requestBodyAndHeader("direct:listAll", "irrelevantBody"); filename1.txt 1252314321 filename2.txt 2897651254
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("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);
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("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);
remove
Removes a file from the GridFS database.
// from("direct:remove").to("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);
GridFS Consumer
See also
- MongoDB website
- NoSQL Wikipedia article
- MongoDB Java driver API docs - current version
- Unit tests for more examples of usage