上面getbean 方法参数是字符串，下面参数是类，@SuppressWarnings("unchecked")有什么用？2个 getbean方法反回的都是接口实例化么？

@SuppressWarnings("unchecked")

protected <T extends Object> T getBean(String beanId) {

try {

return (T)context.getBean(beanId);

} catch (BeansException e) {

e.printStackTrace();

return null;

}

}

protected <T extends Object> T getBean(Class<T> clazz) {

try {

return context.getBean(clazz);

} catch (BeansException e) {

e.printStackTrace();

return null;

}

}