org.brushingbits.jnap.util.BeanLocator.java Source code

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Here is the source code for org.brushingbits.jnap.util.BeanLocator.java

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/*
 * BeanLocator.java created on 2010-01-15
 *
 * Created by Brushing Bits Labs
 * http://www.brushingbits.org
 *
 * 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.brushingbits.jnap.util;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionValidationException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @author Daniel Rochetti
 * @since 1.0
 */
@Component
public final class BeanLocator implements ApplicationContextAware {

    private static BeanLocator instance = null;

    private ApplicationContext applicationContext;

    private BeanLocator() {
    }

    public static BeanLocator get() {
        if (instance == null) {
            instance = new BeanLocator();
        }
        return instance;
    }

    public boolean isInitialized() {
        return this.applicationContext != null;
    }

    /**
     * It's a simple delegate to {@link ApplicationContext#getBean(String, Class)}.
     */
    public <T> T getBean(String name, Class<T> requiredType) {
        return (T) applicationContext.getBean(name, requiredType);
    }

    /**
     * It's a simple delegate to {@link ApplicationContext#getBean(String)}.
     */
    public Object getBeanByName(String name) {
        return applicationContext.getBean(name);
    }

    public <T> T getBean(Class<T> requiredType) {
        String[] beanNames = applicationContext.getBeanNamesForType(requiredType);
        if (beanNames == null || beanNames.length == 0) {
            throw new NoSuchBeanDefinitionException(requiredType, "No bean of the required type was found.");
        }
        if (beanNames.length > 1) {
            throw new BeanDefinitionValidationException(
                    "There are more than " + beanNames.length + "beans implementing the required type. "
                            + "Use 'getBeanByName(String)' or getBean(String, Class) instead.");
        }
        return (T) getBean(beanNames[0], requiredType);
    }

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

    /**
     * 
     * @param unmanagedBean
     */
    public void injectBeans(Object unmanagedBean) {
        AutowireCapableBeanFactory beanFactory = this.applicationContext.getAutowireCapableBeanFactory();
        beanFactory.autowireBeanProperties(unmanagedBean, AutowireCapableBeanFactory.AUTOWIRE_BY_TYPE, true);
    }

}