OptaPlanner

Since Camel 2.13

Both producer and consumer are supported

The Optaplanner component solves the planning problem contained in a message with OptaPlanner.
For example: feed it an unsolved Vehicle Routing problem and it solves it.

The component supports consumer as BestSolutionChangedEvent listener and producer for processing Solution and ProblemFactChange

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

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

URI format

optaplanner:solverConfig[?options]

The solverConfig is the classpath-local URI of the solverConfig, for example /org/foo/barSolverConfig.xml.

You can append query options to the URI in the following format, ?option=value&option=value&…​

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL as a type safe way of configuring endpoints.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The OptaPlanner component supports 3 options, which are listed below.

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

boolean

Endpoint Options

The OptaPlanner endpoint is configured using URI syntax:

optaplanner:configFile

with the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

configFile (common)

Required Specifies the location to the solver file. If useSolverManager=FALSE, Camel uses this file and create the Solver. If useSolverManager=TRUE and SolverManager is set in the header \{OptaPlannerConstants.SOLVER_MANAGER} : this file is ignored by Camel usage of SolverManager. SolverManager can be injected by DI in Quarkus or Spring.

String

Query Parameters (9 parameters)

Name Description Default Type

problemId (common)

In case of using SolverManager : the problem id.

Long

solverId (common)

Specifies the solverId to user for the solver instance key.

String

useSolverManager (common)

use SolverManager instead of XML file config. Use this mode on Quarkus app.

boolean

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

exceptionHandler (consumer (advanced))

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

  • InOptionalOut

ExchangePattern

async (producer)

Specifies to perform operations in async mode.

boolean

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

threadPoolSize (producer)

Specifies the thread pool size to use when async is true.

int

Message Headers

Name Default Value Type Context Description

CamelOptaPlannerSolverId

null

String

Shared

Specifies the solverId to use

CamelOptaPlannerIsAsync

PUT

String

Producer

Specify whether to use another thread for submitting Solution instances rather than blocking the current thread.

Message Body

Camel takes the planning problem for the IN body, solves it and returns it on the OUT body. The IN body object supports the following use cases:

  • If the body is instance of Solution, then it will be solved using the solver identified by solverId and either synchronously or asynchronously.

  • If the body is instance of ProblemFactChange, then it will trigger addProblemFactChange. If the processing is asynchronously, then it will wait till isEveryProblemFactChangeProcessed before returning result.

  • If the body is none of the above types, then the producer will return the best result from the solver identified by solverId

Termination

The solving will take as long as specified in the solverConfig.

<solver>

  <termination>
    <!-- Terminate after 10 seconds, unless it's not feasible by then yet -->
    <terminationCompositionStyle>AND</terminationCompositionStyle>
    <secondsSpentLimit>10</secondsSpentLimit>
    <bestScoreLimit>-1hard/0soft</bestScoreLimit>
  </termination>

</solver>

Samples

Solve an planning problem that’s on the ActiveMQ queue with OptaPlanner:

from("activemq:My.Queue").
  .to("optaplanner:/org/foo/barSolverConfig.xml");

Expose OptaPlanner as a REST service:

from("cxfrs:bean:rsServer?bindingStyle=SimpleConsumer")
  .to("optaplanner:/org/foo/barSolverConfig.xml");

Spring Boot Auto-Configuration

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

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

The component supports 4 options, which are listed below.

Name Description Default Type

camel.component.optaplanner.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.optaplanner.bridge-error-handler

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

Boolean

camel.component.optaplanner.enabled

Whether to enable auto configuration of the optaplanner component. This is enabled by default.

Boolean

camel.component.optaplanner.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean