Dependency injection

The CKFinder 3 for Java connector uses Spring core modules to manage dependency injection. The CKFinder servlet initializes its own internal application context and performs a path scan of the com.cksource.ckfinder package to discover and register all the components. If you need to add a custom path to be scanned for components, you can use the scan-path servlet initialization parameter. To read more about path scan, refer to the Path scan section.

# Registering custom components

The default behavior of the CKFinder connector can be changed and extended by creating custom components. The components should be located in com.cksource.ckfinder or in any other package scanned by the CKFinder’s internal application context.

It is recommended to register custom components and inject dependencies using JSR-330 standard annotations , i.e. @Named and @Inject.

Please note that components registered in this way reside in the CKFinder’s internal application scope, so they may not have direct access to services within your application.

The code listing below presents a simple event listener component that listens for the RequestEvent and logs the query string of the current HTTP request and the server info from the servlet context.

The component class is marked with the @Named annotation. Thanks to this, the component will be instantiated and registered in the application context.

@Inject identifies an injectable field of type ServletContext. This annotation tells the DI container to inject the servlet context instance to the marked class field.

package com.cksource.ckfinder.listener;

import com.cksource.ckfinder.event.RequestEvent;
import com.cksource.ckfinder.listener.Listener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jakarta.inject.Inject;
import jakarta.inject.Named;
import jakarta.servlet.ServletContext;

@Named
public class CustomListener implements Listener<RequestEvent> {
    private static final Logger logger = LoggerFactory.getLogger(CustomListener.class);

    @Inject
    private ServletContext servletContext;

    @Override
    public void onApplicationEvent(RequestEvent requestEvent) {
        logger.info(requestEvent.getRequest().getQueryString());
        logger.info(servletContext.getServerInfo());
    }
}

# Components registered by CKFinder

Below, you can find a list of components registered by the CKFinder connector in its own internal application context. You can access these components inside your own custom components by injecting them through the constructor parameters or class fields.

Type	Scope	Description
Acl	Request	Access control list component. This component controls access to resources using rules defined in the accessControl configuration option.
AclRoleProvider	Application	ACL role provider. Returns the role of the current user to be checked against rules defined in the accessControl configuration option. SessionRoleProvider is the default concrete implementation, which returns the value of the session attribute whose name is defined in the roleSessionAttribute configuration option.
ApplicationContext	Application	CKFinder’s internal application context.
ApplicationEventPublisher	Application	Application event publisher.
Authenticator	Application	Authenticator component used to determine whether the current user should be able to access CKFinder. This component should be defined in the host application code.
BackendFactory	Request	Backend factory service that provides concrete instances of Backend file system wrappers defined in the configuration.
Cache	Request	CKFinder’s internal cache.
CKFinder	Application	The main CKFinder component
CommandFactory	Application	The command factory component that provides concrete instances of Command used to handle HTTP requests.
Config	Request	The connector configuration to use in the current HTTP request scope.
CsrfTokenValidator	Application	The validator service used to validate HTTP requests for CSRF tokens.
FileSystemFactory	Request	The factory that provides instances of FileSystem for backends defined in the configuration.
HttpServletRequest	Request	The current HTTP request.
HttpServletResponse	Request	The current HTTP response.
MessageConverter	Application	The component responsible for assembling HTTP responses.
ResizedImageManager	Request	Component responsible for processing resized images.
ThumbManager	Request	The component responsible for processing internal image thumbnails.
Translator	Application	The component responsible for translation of error messages.
ResourceTypeFactory	Request	The factory that provides instances of ResourceType for resurceTypes defined in the configuration.
ServletContext	Application	The CKFinder’s servlet context.
StaticResourcesHandler	Application	The component responsible for serving static resources when the serveStaticResources configuration option is enabled.
WorkingFolder	Request	The request-scoped component that represents the current working directory in CKFinder.