/*
* Copyright 2013 Stefan Domnanovits
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.codebullets.sagalib.startup;
import com.codebullets.sagalib.AbstractSaga;
import com.codebullets.sagalib.AbstractSingleEventSaga;
import com.codebullets.sagalib.Saga;
import com.google.common.collect.Sets;
import org.reflections.Reflections;
import org.reflections.util.ClasspathHelper;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Set;
import java.util.TreeSet;
/**
* Uses reflections library to scan for saga instances.<p/>
* See <a href="https://code.google.com/p/reflections/">https://code.google.com/p/reflections/</a> for details.
*/
public class ReflectionsTypeScanner implements TypeScanner {
private final Reflections reflections;
/**
* Generates a new instance of ReflectionsTypeScanner.
*/
public ReflectionsTypeScanner() {
reflections = new Reflections(ClasspathHelper.forJavaClassPath());
}
/**
* Generates a new instance of ReflectionsTypeScanner. Allows
* configuration of custom Reflections settings.
*/
public ReflectionsTypeScanner(final Reflections reflections) {
this.reflections = reflections;
}
/**
* {@inheritDoc}
*/
@Override
public Collection<Class<? extends Saga>> scanForSagas() {
Set<Class<? extends Saga>> sagaTypes = reflections.getSubTypesOf(Saga.class);
// separate searches in case saga-lib is in embedded jar when performing directory scanning
Set<Class<? extends AbstractSaga>> abstractSagaTypes = reflections.getSubTypesOf(AbstractSaga.class);
Set<Class<? extends AbstractSingleEventSaga>> singleEventSagaTypes = reflections.getSubTypesOf(AbstractSingleEventSaga.class);
Set<Class<? extends Saga>> foundTypes = Sets.union(sagaTypes, abstractSagaTypes);
Set<Class<? extends Saga>> mergedSet = Sets.union(foundTypes, copy(singleEventSagaTypes));
return removeAbstractTypes(mergedSet);
}
/**
* Creates a new collection with abstract types which can not be instantiated.
*/
private Collection<Class<? extends Saga>> removeAbstractTypes(final Collection<Class<? extends Saga>> foundTypes) {
Collection<Class<? extends Saga>> sagaTypes = new ArrayList<>();
for (Class<? extends Saga> entryType : foundTypes) {
if (!Modifier.isAbstract(entryType.getModifiers())) {
sagaTypes.add(entryType);
}
}
return sagaTypes;
}
private Set<Class<? extends Saga>> copy(final Set<Class<? extends AbstractSingleEventSaga>> source) {
Set<Class<? extends Saga>> target = new TreeSet<>();
for (Class<? extends Saga> entry : source) {
target.add(entry);
}
return target;
}
}