Solr Component

Available as of Camel version 2.9

The Solr component allows you to interface with an Apache Lucene Solr server (based on SolrJ 3.5.0).

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

NOTE: solrs and solrCloud are new added since Camel 2.14.

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

Solr Options

The Solr component has no options.

The Solr endpoint is configured using URI syntax:

solr:url

with the following path and query parameters:

Path Parameters (1 parameters):

Name Description Default Type

url

Required Hostname and port for the solr server

String

Query Parameters (15 parameters):

Name Description Default Type

allowCompression (producer)

Server side must support gzip or deflate for this to have any effect

Boolean

connectionTimeout (producer)

connectionTimeout on the underlying HttpConnectionManager

Integer

defaultMaxConnectionsPer Host (producer)

maxConnectionsPerHost on the underlying HttpConnectionManager

Integer

followRedirects (producer)

indicates whether redirects are used to get to the Solr server

Boolean

maxRetries (producer)

Maximum number of retries to attempt in the event of transient errors

Integer

maxTotalConnections (producer)

maxTotalConnection on the underlying HttpConnectionManager

Integer

requestHandler (producer)

Set the request handler to be used

String

soTimeout (producer)

Read timeout on the underlying HttpConnectionManager. This is desirable for queries, but probably not for indexing

Integer

streamingQueueSize (producer)

Set the queue size for the StreamingUpdateSolrServer

10

int

streamingThreadCount (producer)

Set the number of threads for the StreamingUpdateSolrServer

2

int

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

password (security)

Sets password for basic auth plugin enabled servers

String

username (security)

Sets username for basic auth plugin enabled servers

String

collection (solrCloud)

Set the collection name which the solrCloud server could use

String

zkHost (solrCloud)

Set the ZooKeeper host information which the solrCloud could use, such as zkhost=localhost:8123.

String

Spring Boot Auto-Configuration

When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

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

The component supports 2 options, which are listed below.

Name Description Default Type

camel.component.solr.enabled

Enable solr component

true

Boolean

camel.component.solr.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

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/INSERT_STREAMING

n/a

adds an index using message headers (must be prefixed with "SolrField.")

INSERT/INSERT_STREAMING

File

adds an index using the given File (using ContentStreamUpdateRequest)

INSERT/INSERT_STREAMING

SolrInputDocument

Camel 2.9.2 updates index based on the given SolrInputDocument

INSERT/INSERT_STREAMING

String XML

Camel 2.9.2 updates index based on the given XML (must follow SolrInputDocument format)

ADD_BEAN

bean instance

adds an index based on values in an annotated bean

ADD_BEANS

collection<bean>

Camel 2.15 adds index based on a collection of 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, DELETE 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:delete")
    .setHeader(SolrConstants.OPERATION, constant(SolrConstants.OPERATION_DELETE_BY_ID))
    .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:delete"/>
    <setHeader headerName="SolrOperation">
        <constant>DELETE_BY_ID</constant>
    </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 or delete routes and then call the commit route.

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