提供靜態方法獲取spring bean實例

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * 提供靜態方法獲取spring bean實例
 * 
 * @author
 *
 */
@Component
public class SpringContextUtils implements ApplicationContextAware {

    //將相關服務注入Spring框架
    @Autowired
    private ImportValidateService _importValidateService;
        
    @Autowired
    private CallBackService _callBackService;
    
    private static ApplicationContext _applicationContext = null;

    private static SpringContextUtils _self;

    public static <T> T getBean(Class<T> requiredType) {
        if (_applicationContext != null) {
            return _applicationContext.getBean(requiredType);
        } else {
            throw new org.springframework.context.ApplicationContextException("ApplicationContext has not been set.");
        }
    }

    public synchronized static ImportValidateService getValidateService() {
        return self()._importValidateService;
    }

    
    public synchronized static CallBackService getCallBackService() {
        return self()._callBackService;
    }

    private static SpringContextUtils self() {
        if (_self == null) {
            if (_applicationContext != null) {
                _self = _applicationContext.getBean(SpringContextUtils.class);
            } else {
                throw new org.springframework.context.ApplicationContextException(
                        "ApplicationContext has not been set.");
            }
        }
        return _self;
    }

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

}