StepClassFilter.java

/*
 *     Copyright Technophobia Ltd 2012
 *
 *   This file is part of Substeps.
 *
 *    Substeps is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU Lesser General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    Substeps is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Lesser General Public License for more details.
 *
 *    You should have received a copy of the GNU Lesser General Public License
 *    along with Substeps.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.technophobia.substeps.runner.runtime;

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Predicate;
import com.technophobia.substeps.model.SubSteps;

public class StepClassFilter implements Predicate<Class<?>> {

    private static final Logger LOG = LoggerFactory.getLogger(StepClassFilter.class);


    public boolean apply(final Class<?> clazz) {
        LOG.debug("Checking if " + clazz.getName() + " has step methods");
        try {
            if (hasAnnotation(clazz, SubSteps.AdditionalStepImplementations.class)) {
                LOG.debug("Class " + clazz + " has " + SubSteps.AdditionalStepImplementations.class.getName()
                        + " annotation, returning true");
                return true;
            }
            for (final Method method : clazz.getMethods()) {
                if (hasAnnotation(method, SubSteps.Step.class)) {
                    LOG.debug("Class " + clazz + " has method" + method.getName() + " annotated with the "
                            + SubSteps.AdditionalStepImplementations.class.getName() + " annotation, returning true");
                    return true;
                }
            }

            LOG.debug("Class " + clazz + " does not appear to be a step class");
        } catch (final Exception ex) {
            LOG.warn("Encountered exception " + ex.getClass().getName() + " while trying to determine if class "
                    + clazz + " is a step class. This is probably because eclipse hasn't loaded this class yet.");
        } catch (final LinkageError err) {
            LOG.warn("Encountered error " + err.getClass().getName() + " while trying to determine if class " + clazz
                    + " is a step class. This is probably because eclipse hasn't loaded this class yet.");
        }
        return false;
    }


    private boolean hasAnnotation(final Method method, final Class<?> annotationClass) {
        return hasAnnotation(method.getAnnotations(), annotationClass);
    }


    private boolean hasAnnotation(final Class<?> clazz, final Class<?> annotationClass) {
        try {
            return hasAnnotation(clazz.getAnnotations(), annotationClass);
        } catch (final ArrayStoreException ex) {
            LOG.warn("ArrayStoreException encountered when querying "
                    + clazz.getName()
                    + ".getAnnotations(). This usually implies the classes annotations are not on the build path - is this class compiling? Returning false for now");
            return false;
        }
    }


    private boolean hasAnnotation(final Annotation[] annotations, final Class<?> annotationClass) {
        // compare the class names rather than the classes themselves, as its
        // entirely possible that the class was created in a different
        // classloader to
        // the current classs (e.g. if this is the eclipse plugin)
        for (final Annotation annotation : annotations) {
            if (annotation.annotationType().getName().equals(annotationClass.getName())) {
                return true;
            }
        }
        return false;
    }

}