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> |
mongodb-gridfs:connectionBean?database=databaseName&bucket=bucketName[&moreOptions...] |
gridfs:connectionBean?database=databaseName&bucket=bucketName[&moreOptions...] |
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. | ||
persistentTSObject | 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 |
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> |
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="mongodb-gridfs:mongoBean?database=${mongodb.database}&operation=findOne" /> <to uri="direct:result" /> </route> |
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); |
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 |
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); |
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); |
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); |
The GridFS component will poll GridFS periodically for new files to process. The two parameters that control this behavior are the delay and initialDelay parameters. The delay parameter specifies how long the background tread will sleep between polling attempts. The default is 500ms. The initialDelay parameter specifies how long the consumer will wait after starting before polling the first time. This is useful if the backend service needs a bit longer to become available.
The Consumer has several strategies for determining which files within the grid have not been processed yet:
from("mongodb-gridfs?database=tickets&queryStrategy=FileAttribute").process(.....); from("mongodb-gridfs?database=myData&queryStrategy=PersistentTimestamp&persistentTSCollection=CamelTimestamps&persistentTSObject=myDataTS").process(...) |
See also