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/* 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 org.flowable.cdi.impl.util;

import java.lang.reflect.Type;
import java.util.Iterator;
import java.util.Set;

import javax.enterprise.context.spi.CreationalContext;
import javax.enterprise.inject.spi.Bean;
import javax.enterprise.inject.spi.BeanManager;

/**
 * Utility class for performing programmatic bean lookups.
 * 
 * @author Daniel Meyer
 */
public class ProgrammaticBeanLookup {

    @SuppressWarnings("unchecked")
    public static  T lookup(Class clazz, BeanManager bm) {
        Iterator> iter = bm.getBeans(clazz).iterator();
        if (!iter.hasNext()) {
            throw new IllegalStateException("CDI BeanManager cannot find an instance of requested type " + clazz.getName());
        }
        Bean bean = (Bean) iter.next();
        CreationalContext ctx = bm.createCreationalContext(bean);
        T dao = (T) bm.getReference(bean, clazz, ctx);
        return dao;
    }

    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static Object lookup(String name, BeanManager bm) {
        Set> beans = bm.getBeans(name);
        if (beans.isEmpty()) {
            throw new IllegalStateException("CDI BeanManager cannot find an instance of requested type '" + name + "'");
        }
        Bean bean = bm.resolve(beans);
        CreationalContext ctx = bm.createCreationalContext(bean);
        // select one beantype randomly. A bean has a non-empty set of
        // beantypes.
        Type type = (Type) bean.getTypes().iterator().next();
        return bm.getReference(bean, type, ctx);
    }

    public static  T lookup(Class clazz) {
        BeanManager bm = BeanManagerLookup.getBeanManager();
        return lookup(clazz, bm);
    }

    public static Object lookup(String name) {
        BeanManager bm = BeanManagerLookup.getBeanManager();
        return lookup(name, bm);
    }

}