ApplicationContextFacade.java 文件源码

@Override
@SuppressWarnings("unchecked") // doPrivileged() returns the correct type
public <T extends Filter> T createFilter(Class<T> c) throws ServletException {
    if (SecurityUtil.isPackageProtectionEnabled()) {
        try {
            return (T) invokeMethod(context, "createFilter", new Object[] { c });
        } catch (Throwable t) {
            ExceptionUtils.handleThrowable(t);
            if (t instanceof ServletException) {
                throw (ServletException) t;
            }
            return null;
        }
    } else {
        return context.createFilter(c);
    }
}