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	false	server side must support gzip or deflate for this to have any effect
requestHandler	/update (xml)	set the request handler to be used

Message 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 and COMMIT example

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

from("direct:commit")
    .setHeader(SolrConstants.OPERATION, constant(SolrConstants.OPERATION_COMMIT))
    .to("solr://localhost:8983/solr");

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

A client would simply need to pass a body message to the insert route and then call the commit route.

    template.sendBody("direct:insert", "1234");
    template.sendBody("direct:commit", null);

Querying Solr

Currently, this component doesn't support querying data natively (may be added later). For now, you can query Solr using HTTP as follows:

//define the route to perform a basic query
from("direct:query")
    .recipientList(simple("http://localhost:8983/solr/select/?q=${body}"))
    .convertBodyTo(String.class);
...
//query for an id of '1234' (url encoded)
String responseXml = (String) template.requestBody("direct:query", "id%3A1234");

For more information, see these resources...

Solr Query Tutorial

Solr Query Syntax

Child pages