JBehaveNeedleConfiguration.java

package org.jbehave.core.steps.needle.configuration;

import java.util.HashSet;
import java.util.ResourceBundle;
import java.util.Set;

import org.needle4j.injection.InjectionProvider;
import org.needle4j.injection.InjectionProviderInstancesSupplier;

/**
 * Reads jbehave-needle.properties to initialize additional {@link InjectionProvider}s.
 * 
 * @author Jan Galinski, Holisticon AG (jan.galinski@holisticon.de)
 * @author Simon Zambrovski, Holisticon AG (simon.zambrovski@holisticon.de)
 */
public class JBehaveNeedleConfiguration {
    /**
     * Default properties field name.
     */
    public static final String RESOURCE_JBEHAVE_NEEDLE = "jbehave-needle";

    private final LoadResourceBundle loadResourceBundle = LoadResourceBundle.INSTANCE;
    private final ReadInjectionProviderClassNames readInjectionProviderClassNames =
            ReadInjectionProviderClassNames.INSTANCE;
    private final CreateInstanceByDefaultConstructor createInstance = CreateInstanceByDefaultConstructor.INSTANCE;

    private final Set<InjectionProvider<?>> injectionProviders = new HashSet<>();

    /**
     * Creates new instance from default resource {@link #RESOURCE_JBEHAVE_NEEDLE}.
     */
    public JBehaveNeedleConfiguration() {
        this(RESOURCE_JBEHAVE_NEEDLE);
    }

    public JBehaveNeedleConfiguration(final String resourceName) {
        final ResourceBundle resourceBundle = loadResourceBundle.apply(resourceName);
        final Set<String> classNames = readInjectionProviderClassNames.apply(resourceBundle);

        for (final String className : classNames) {
            try {
                final Class<?> clazz = Class.forName(className);
                if (isInjectionProvider(clazz)) {
                    injectionProviders.add((InjectionProvider<?>) createInstance.apply(clazz));
                } else if (isInjectionProviderInstanceSupplier(clazz)) {
                    final InjectionProviderInstancesSupplier supplier =
                            (InjectionProviderInstancesSupplier) createInstance.apply(clazz);
                    final Set<InjectionProvider<?>> providers = supplier.get();
                    if (providers != null) {
                        injectionProviders.addAll(providers);
                    }
                }
            } catch (final Exception e) {
                throw new IllegalStateException("failed to initialize custom injection providers", e);
            }
        }
    }

    public InjectionProvider<?>[] getInjectionProviders() {
        return injectionProviders.toArray(new InjectionProvider<?>[injectionProviders.size()]);
    }

    /**
     * Checks if given class is an {@link InjectionProvider}
     * 
     * @param type
     *            Class to check
     * @return <code>true</code> if type can be cast to {@link InjectionProvider}
     */
    static boolean isInjectionProvider(final Class<?> type) {
        return InjectionProvider.class.isAssignableFrom(type);
    }

    /**
     * Checks if given class is an {@link InjectionProviderInstancesSupplier}
     * 
     * @param type
     *            Class to check
     * @return <code>true</code> if type can be cast to {@link InjectionProviderInstancesSupplier}
     */
    static boolean isInjectionProviderInstanceSupplier(final Class<?> type) {
        return InjectionProviderInstancesSupplier.class.isAssignableFrom(type);
    }
}