org.openl.rules.project.instantiation.RulesInstantiationStrategy Maven / Gradle / Ivy

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Classes and utilities to work with OpenL Rules Project
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package org.openl.rules.project.instantiation;

import java.util.Collection;
import java.util.Map;

import org.openl.CompiledOpenClass;
import org.openl.classloader.SimpleBundleClassLoader;
import org.openl.rules.project.model.Module;

/**
 * Compiles {@link Module}s and gets {@link CompiledOpenClass} and instance of
 * for execution
 * 
 * @author PUdalau, Marat Kamalov
 */
public interface RulesInstantiationStrategy {
    
    /**
     * Compiles module.
     * 
     * @return CompiledOpenClass that represents overall info about module
     *         rules.
     * @throws RulesInstantiationException
     */
    CompiledOpenClass compile() throws RulesInstantiationException;

    /**
     * Creates instance of class handling all rules invocations. The class will
     * be instance of class got with {@link #getInstanceClass()()}.
     * 
     * @return instance of {@link #getInstanceClass()} result.
     * @throws RulesInstantiationException
     * @throws ClassNotFoundException
     */
    Object instantiate() throws RulesInstantiationException, ClassNotFoundException;

    /**
     * Returns ClassLoader for the current module inside the project. If
     * classLoader was set during the construction of the strategy - returns it.

     * If no, creates {@link SimpleBundleClassLoader} with project classLoader
     * of current module as parent.
     * 
     * @return {@link ClassLoader} that will be used for openl compilation.
     * 
     * throws RulesInstantiationException some strategies compile dependencie during classloader build.
     */
    ClassLoader getClassLoader()  throws RulesInstantiationException;

    /**
     * Service class of rules can be defined by user or it is predefined for
     * some specific instantiations strategies(e.g. for static wrapper case).
     * 
     * @return service class that it is used for {@link InstantiationError} or
     *         null.
     * @throws ClassNotFoundException
     */
    Class getServiceClass() throws ClassNotFoundException;

    /**
     * Service that will be used for instantiation.
     * 
     * @param serviceClass service class.
     */
    void setServiceClass(Class serviceClass);

    /**
     * Generates interfaces corresponding rules.
     * 
     * @return generated interface for rules.
     * @throws RulesInstantiationException
     */
    Class getGeneratedRulesClass() throws RulesInstantiationException;

    /**
     * Recognizes class for instance representing rule. It will be service class
     * or generated by rules class it the first one is not defined.
     * 
     * @return class of instance.
     * @throws ClassNotFoundException
     * @throws RulesInstantiationException
     */
    Class getInstanceClass() throws ClassNotFoundException, RulesInstantiationException;

    /**
     * @return true if service class is defined.
     */
    boolean isServiceClassDefined();

    /**
     * Resets instantiation strategy in order to check out all changes in
     * modules.
     */
    void reset();

    /**
     * Forced reset that is improved version of {@link #reset()} with reloading
     * of classloaders.
     */
    void forcedReset();

    /**
     * @return Modules used for compilation.
     */
    Collection getModules();
    
    /**
     * Some additional options for compilation defined externally(e.g. external
     * dependencies, overridden system properties)
     */
    Map getExternalParameters();

    void setExternalParameters(Map parameters);

}