# Dependencies { #dependencies }

**FastAPI** has a very powerful but intuitive **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection" { #what-is-dependency-injection }

 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * Provides a caching infrastructure for Maven requests and their results.
 * <p>
 * This package contains the core components for implementing and managing caches in Maven:
 * <ul>
 *   <li>{@link org.apache.maven.api.cache.RequestCache} - The main interface for caching request results</li>

            }

            @Override
            public String getIndexDocumentUpdateIndex() {
                return documentUpdateIndex;
            }
        };

        // Register components
        ComponentUtil.register(searchEngineClient, "searchEngineClient");
        ComponentUtil.setFessConfig(fessConfig);
    }

    @Override
    public void tearDown() throws Exception {
        super.tearDown();

 * <p>
 * The class uses a {@link CrawlerContainer} for managing crawler components and
 * supports dependency injection via the {@link Resource} annotation.
 * </p>
 */
public class ExtractorFactory {

    /** Logger instance for this class */
    private static final Logger logger = LogManager.getLogger(ExtractorFactory.class);

    /** Container for managing crawler components */
    @Resource
    protected CrawlerContainer crawlerContainer;

* Caddy
    * Handhabt automatisch Zertifikat-Erneuerungen ✨
* Nginx
    * Mit einer externen Komponente wie Certbot für Zertifikat-Erneuerungen
* HAProxy
    * Mit einer externen Komponente wie Certbot für Zertifikat-Erneuerungen
* Kubernetes mit einem Ingress Controller wie Nginx
    * Mit einer externen Komponente wie cert-manager für Zertifikat-Erneuerungen

 */
public class FessActionValidator<MESSAGES extends UserMessages> extends ActionValidator<MESSAGES> {

    /**
     * Constructs a new FessActionValidator with the specified components.
     *
     * @param requestManager the request manager for handling HTTP requests
     * @param messagesCreator the creator for user messages
     * @param runtimeGroups the runtime validation groups
     */

 *
 * <p>It implements the Runnable interface to be executed in a separate thread,
 * and the AutoCloseable interface to ensure resources are properly released after use.
 *
 * <p>The crawler uses several services and components, such as UrlQueueService, DataService,
 * UrlFilter, RuleManager, CrawlerContainer, IntervalController, and CrawlerClientFactory,
 * to perform its tasks.
 *
 * <p>The crawling process involves the following steps:
 * <ol>

 * under the License.
 */
package org.apache.maven.toolchain;

import java.util.Map;

import org.apache.maven.toolchain.model.ToolchainModel;

/**
 * a private contract between the toolchains plugin and the components.
 *
 * @deprecated Use {@link org.apache.maven.api.Toolchain} instead.
 */
@Deprecated(since = "4.0.0")
public interface ToolchainPrivate extends Toolchain {

    /**

    bus.register(compCatcher);

    // Two additional event types: Object and Comparable<?> (played by Integer)
    Object objEvent = new Object();
    Object compEvent = 6;

    bus.post(EVENT);
    bus.post(objEvent);
    bus.post(compEvent);

    // Check the StringCatcher...
    List<String> stringEvents = stringCatcher.getEvents();
    assertEquals("Only one String should be delivered.", 1, stringEvents.size());

 * These classes are immutable to ensure thread safety and prevent unintended modifications.
 * The root class is {@link org.apache.maven.api.model.Model}, which represents the entire POM.
 * <p>
 * Key components include:
 * <ul>
 *   <li>{@link org.apache.maven.api.model.Model} - The root element of a POM file</li>
 *   <li>{@link org.apache.maven.api.model.Dependency} - Represents a project dependency</li>