com.monarchapis.driver.util.SpringServiceResolver.java Source code

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Here is the source code for com.monarchapis.driver.util.SpringServiceResolver.java

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/*
 * Copyright (C) 2015 CapTech Ventures, Inc.
 * (http://www.captechconsulting.com) All Rights Reserved.
 *
 * 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.monarchapis.driver.util;

import java.util.ArrayList;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

import com.google.common.base.Optional;

/**
 * A Spring implementation of ServiceResolver that uses
 * <code>ApplicationContext</code> to look up beans.
 * 
 * @author Phil Kedy
 */
public class SpringServiceResolver extends ServiceResolver implements ApplicationContextAware {
    /**
     * The application context.
     */
    private ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }

    /**
     * Initializes the service resolver singleton.
     */
    @PostConstruct
    public void init() {
        ServiceResolver.setInstance(this);
    }

    /**
     * Unsets the service resolver singleton.
     */
    @PreDestroy
    public void destroy() {
        ServiceResolver.setInstance(null);
    }

    @Override
    public <T> T required(Class<T> clazz) {
        return applicationContext.getBean(clazz);
    }

    @Override
    public <T> Optional<T> optional(Class<T> clazz) {
        try {
            return Optional.of(applicationContext.getBean(clazz));
        } catch (BeansException be) {
            return Optional.absent();
        }
    }

    @SuppressWarnings("unchecked")
    @Override
    public <T> List<T> getInstancesOf(Class<T> clazz) {
        String[] names = applicationContext.getBeanNamesForType(clazz);

        List<T> beans = new ArrayList<T>(names.length);

        for (String name : names) {
            beans.add((T) applicationContext.getBean(name));
        }

        return beans;
    }
}