com.sun.jersey.server.impl.cdi.Utils Maven / Gradle / Ivy

Go to download
/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2010-2011 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * http://glassfish.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */
 
package com.sun.jersey.server.impl.cdi;

import java.util.Collections;
import java.util.Set;
import javax.enterprise.context.spi.CreationalContext;
import javax.enterprise.inject.AmbiguousResolutionException;
import javax.enterprise.inject.spi.Bean;
import javax.enterprise.inject.spi.BeanManager;

/**
  * Utility methods for CDI BeanManager and Bean classes.
  *
  * @author robc
  * @author [email protected]
  */
public class Utils {

    private Utils() {}
    
    public static Bean getBean(BeanManager bm, Class c) {
        final Set> bs = bm.getBeans(c);
        if (bs.isEmpty()) {
            return null;
        }

        try {
            return bm.resolve(bs);
        } catch(AmbiguousResolutionException ex) {
            // Check if there is a shared base class of c
            // If so reduce the set of beans whose class equals c and resolve
            if (isSharedBaseClass(c, bs)) {
                try {
                    return bm.resolve(getBaseClassSubSet(c, bs));
                } catch (AmbiguousResolutionException ex2) {
                    return null;
                }
            }
            return null;
        }
    }

    public static  T getInstance(BeanManager bm, Class c) {
        Bean b = getBean(bm, c);
        if (b == null) {
            return null;
        }
        
        CreationalContext cc = bm.createCreationalContext(b);
        return c.cast(bm.getReference(b, c, cc));
    }
    
    private static boolean isSharedBaseClass(Class c, Set> bs) {
        for (Bean b : bs) {
            if (!c.isAssignableFrom(b.getBeanClass())) {
                return false;
            }
        }
        return true;
    }

    private static Set> getBaseClassSubSet(Class c, Set> bs) {
        for (Bean b : bs) {
            if (c == b.getBeanClass()) {
                return Collections.>singleton(b);
            }
        }
        return bs;
    }

}