SpringComponentProvider is dependent on ServletContext which doesn't exist in non-servlet container case

SpringComponentProvider is dependent on ServletContext which doesn't exist in non-servlet container case. So it will cause ClassNotFoundException in non-servlet container case where ServletContext.class can not be found.

The related code in SpringComponentProvider.initialize

```java
ServletContext sc = locator.getService(ServletContext.class);

if (sc != null) {
// servlet container
ctx = WebApplicationContextUtils.getWebApplicationContext(sc);
} else {
// non-servlet container
ctx = createSpringContext();
}
```