ReflectionHelper.java

package org.jbehave.scenario.finegrained.junit.monitoring;

import org.jbehave.scenario.Configuration;
import org.jbehave.scenario.JUnitScenario;
import org.jbehave.scenario.reporters.ScenarioReporter;
import org.jbehave.scenario.steps.Steps;

import java.lang.annotation.Annotation;

public class ReflectionHelper {

    private final Class<?> invokingClass;

    private final Class<? extends JUnitScenario> testClass;

    public ReflectionHelper(Class<?> invokingClass, Class<? extends JUnitScenario> testClass) {
        this.invokingClass = invokingClass;
        this.testClass = testClass;

    }

    public <T> T getInstance(Class<T> targetClass) {
        try {
            return targetClass.newInstance();
        } catch (Exception e) {
            throw new IllegalArgumentException(targetClass.toString()
                    + " must have default constructor to use custom runner "
                    + invokingClass.toString());
        }
    }

    public void checkForAnnotation(Class<? extends Annotation> annotationClass) {
        Annotation annotation = testClass.getAnnotation(annotationClass);
        if (annotation == null) {
            throw new IllegalArgumentException(testClass.toString() + " must declare annotation "
                    + annotationClass.toString() + " to use custom runner "
                    + invokingClass.toString());
        }
    }

    public Configuration reflectMeAConfiguration() {
        checkForAnnotation(UseConfiguration.class);
        Class<? extends Configuration> configurationClass = testClass.getAnnotation(
                UseConfiguration.class).value();
        return getInstance(configurationClass);
    }

    public Steps reflectMeCandidateSteps() {
        checkForAnnotation(UseSteps.class);
        Class<? extends Steps> StepsClass = testClass.getAnnotation(UseSteps.class).value();
        return getInstance(StepsClass);
    }

    public JUnitScenario reflectMeATestInstance(JUnitScenarioReporter reporter) {
        try {
            return testClass.getConstructor(ScenarioReporter.class).newInstance(reporter);
        } catch (Exception e) {
            throw new IllegalArgumentException(testClass.toString()
                    + "must have constructor with the following args: ("
                    + ClassLoader.class.toString() + ", " + ScenarioReporter.class.toString()
                    + ") in order to use custom runner " + this.getClass().toString(), e);
        }
    }
}