Solr

Solr Component

Available as of Camel 2.9

The Solr component allows you to interface with an Apache Lucene Solr server.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-solr</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

solr://host[:port]/solr?[options]

Endpoint Options

The following SolrServer options may be configured on the Solr endpoint.

name	default value	description
maxRetries	0	maximum number of retries to attempt in the event of transient errors
soTimeout	1000	read timeout on the underlying HttpConnectionManager. This is desirable for queries, but probably not for indexing
connectionTimeout	100	connectionTimeout on the underlying HttpConnectionManager
defaultMaxConnectionsPerHost	2	maxConnectionsPerHost on the underlying HttpConnectionManager
maxTotalConnections	20	maxTotalConnection on the underlying HttpConnectionManager
followRedirects	false	indicates whether redirects are used to get to the Solr server
allowCompression	true	server side must support gzip or deflate for this to have any effect
requestHandler	/update (xml)	set the request handler to be used

Operations

The following Solr operations are currently supported. Simply set an exchange header with a key of "SolrOperation" and a value set to one of the following. Some operations also require the message body to be set.

operation	message body	description
INSERT	n/a	insert a new record based on headers values (headers must be prefixed with "SolrField.")
ADD_BEAN	bean instance	insert a new record based on values in an annotated bean
DELETE_BY_ID	index id to delete	delete a record by ID
DELETE_BY_QUERY	query string	delete a record by a query
COMMIT	n/a	performs a commit on any pending index changes
ROLLBACK	n/a	performs a rollback on any pending index changes
OPTIMIZE	n/a	performs a commit on any pending index changes and then runs the optimize command

Example

Below is a simple INSERT example in Java and Spring XML.

from("direct:start")
    .setHeader(SolrConstants.OPERATION, constant(SolrConstants.OPERATION_INSERT))
    .setHeader(SolrConstants.FIELD + "id", body())
    .to("solr://localhost:8983/solr");

<route>
    <from uri="direct:start"/>
    <setHeader headerName="SolrOperation">
        <constant>INSERT</constant>
    </setHeader>
    <setHeader headerName="SolrField.id">
        <simple>${body}</simple>
    </setHeader>
    <to uri="solr://localhost:8983/solr"/>
</route>

A client would simply need to pass a body message to this route as follows.

    template.sendBody("direct:start", "value1");

Querying Solr

Currently, this component doesn't support querying data (will be added later). For now, you can query Solr in a route using HTTP.

TODO: add a simple example to retrieve the data inserted above.

For more information, see these resources...

Solr Query Tutorial

Solr Query Syntax

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