Build a Solver instance with the SolverFactory. Configure the SolverFactory with a solver configuration XML file, provided as a classpath resource (as defined by ClassLoader.getResource()):

       SolverFactory<NQueens> solverFactory = SolverFactory.createFromXmlResource(
               "org/optaplanner/examples/nqueens/solver/nqueensSolverConfig.xml");
       Solver<NQueens> solver = solverFactory.buildSolver();

In a typical project (following the Maven directory structure), that solverConfig XML file would be located at $PROJECT_DIR/src/main/resources/org/optaplanner/examples/nqueens/solver/nqueensSolverConfig.xml. Alternatively, a SolverFactory can be created from a File, an InputStream or a Reader with methods such as SolverFactory.createFromXmlFile(). However, for portability reasons, a classpath resource is recommended.

       SolverFactory<NQueens> solverFactory = SolverFactory.createFromXmlResource(
               ".../nqueensSolverConfig.xml", getClass().getClassLoader());

       KieServices kieServices = KieServices.Factory.get();
       KieContainer kieContainer = kieServices.newKieContainer(
               kieServices.newReleaseId("org.nqueens", "nqueens", "1.0.0"));
       SolverFactory<NQueens> solverFactory = SolverFactory.createFromKieContainerXmlResource(
               kieContainer, ".../nqueensSolverConfig.xml");

Both a Solver and a SolverFactory have a generic type called Solution_, which is the class representing a planning problem and solution.

A solver configuration XML file looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<solver>
  <!-- Define the model -->
  <solutionClass>org.optaplanner.examples.nqueens.domain.NQueens</solutionClass>
  <entityClass>org.optaplanner.examples.nqueens.domain.Queen</entityClass>

  <!-- Define the score function -->
  <scoreDirectorFactory>
    <scoreDefinitionType>SIMPLE</scoreDefinitionType>
    <scoreDrl>org/optaplanner/examples/nqueens/solver/nQueensScoreRules.drl</scoreDrl>
  </scoreDirectorFactory>

  <!-- Configure the optimization algorithms (optional) -->
  <termination>
    ...
  </termination>
  <constructionHeuristic>
    ...
  </constructionHeuristic>
  <localSearch>
    ...
  </localSearch>
</solver>

Notice the three parts in it:

These various parts of a configuration are explained further in this manual.

Planner makes it relatively easy to switch optimization algorithm(s) just by changing the configuration. There is even a Benchmarker which allows you to play out different configurations against each other and report the most appropriate configuration for your use case.

A solver configuration can also be configured with the SolverConfig API. This is especially useful to change some values dynamically at runtime. For example, to change the running time based on user input, before building the Solver:

        SolverFactory<NQueens> solverFactory = SolverFactory.createFromXmlResource(
                "org/optaplanner/examples/nqueens/solver/nqueensSolverConfig.xml");

        TerminationConfig terminationConfig = new TerminationConfig();
        terminationConfig.setMinutesSpentLimit(userInput);
        solverFactory.getSolverConfig().setTerminationConfig(terminationConfig);

        Solver<NQueens> solver = solverFactory.buildSolver();

Every element in the solver configuration XML is available as a *Config class or a property on a *Config class in the package namespace org.optaplanner.core.config. These *Config classes are the Java representation of the XML format. They build the runtime components (of the package namespace org.optaplanner.core.impl) and assemble them into an efficient Solver.

    private SolverFactory<NQueens> base;

    public void init() {
        base = SolverFactory.createFromXmlResource(
                "org/optaplanner/examples/nqueens/solver/nqueensSolverConfig.xml");
        base.getSolverConfig().setTerminationConfig(new TerminationConfig());
    }

    // Called concurrently from different threads
    public void userRequest(..., long userInput)
        SolverFactory<NQueens> solverFactory = base.cloneSolverFactory();
        solverFactory.getSolverConfig().getTerminationConfig().setMinutesSpentLimit(userInput);
        Solver<NQueens> solver = solverFactory.buildSolver();
        ...
    }

To configure your solver, you can use the Solver Editor in Business Central. To learn about Business Central, see chapter 1.4. Business Central from Red Hat JBoss BPM Suite User Guide.

Click New Item → Solver configuration to create the Solver Editor in your Business Central. Note that you can also use other assets, for example DRL rules, or guided decision tables.

Figure 4.1. Solver Configuration Editor

The solver editor creates a basic solver configuration. You can run it, together with DRL rules, planner entities, and planner solution, in the Intelligent Process Server or in plain Java code after the KJAR is deployed.

Once you define your solver in the editor, you can click Source and view it in the XML format:

<solver xStreamId="1">
  <scanAnnotatedClasses xStreamId="2"/>
  <scoreDirectorFactory xStreamId="3">
    <scoreDefinitionType>HARD_SOFT</scoreDefinitionType>
  </scoreDirectorFactory>
  <termination xStreamId="4">
    <secondsSpentLimit>0</secondsSpentLimit>
    <minutesSpentLimit>0</minutesSpentLimit>
    <hoursSpentLimit>5</hoursSpentLimit>
    <daysSpentLimit>0</daysSpentLimit>
  </termination>
</solver>

Use the Validate button to validate the solver configuration. This will actually build a Solver, so most issues in your project will present themselves then, without the need to deploy and run it.

By default, the solver configuration will automatically scan for all planning entities and a planning solution classes. If none are found (or too many), validation will fail.

Data Object Tab

To model planning entities and planning solutions used in Business Resource Planner, use data objects. To learn more about data objects, see chapter 4.14. Data models from Red Hat JBoss BPM Suite User Guide. To designate a data object as a planner entity or solution, see the following steps:

Figure 4.2. Data Object Tab