│   ├── collection/     # Enhanced collection utilities
│   ├── convert/        # Type conversion utilities
│   ├── exception/      # Runtime exception wrappers
│   ├── io/            # I/O and resource management
│   ├── lang/          # Reflection and language utilities
│   ├── log/           # Logging abstraction
│   ├── text/          # Text processing utilities
│   ├── xml/           # XML processing utilities

 *
 * <h2>Contents</h2>
 *
 * <h3>Value types</h3>
 *
 * <ul>
 *   <li>{@link ImmutableDoubleArray}
 *   <li>{@link ImmutableIntArray}
 *   <li>{@link ImmutableLongArray}
 *   <li>{@link UnsignedInteger}
 *   <li>{@link UnsignedLong}
 * </ul>
 *
 * <h3>Per-type static utilities</h3>
 *
 * <ul>
 *   <li>{@link Booleans}

The most complex problem is building an authentication/authorization provider like those, but **FastAPI** gives you the tools to do it easily, while doing the heavy lifting for you.

///

## **FastAPI** utilities { #fastapi-utilities }

FastAPI provides several tools for each of these security schemes in the `fastapi.security` module that simplify using these security mechanisms.

# Use Old 403 Authentication Error Status Codes { #use-old-403-authentication-error-status-codes }

Before FastAPI version `0.122.0`, when the integrated security utilities returned an error to the client after a failed authentication, they used the HTTP status code `403 Forbidden`.

 * the License.
 */

/**
 * {@linkplain CacheBuilder Discouraged} (in favor of <a
 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>) caching utilities.
 *
 * <p>The core interface used to represent caches is {@link Cache}. In-memory caches can be
 * configured and created using {@link CacheBuilder}, with cache entries being loaded by {@link

import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicBoolean;
import org.jspecify.annotations.Nullable;

/**
 * Utilities necessary for working with libraries that supply plain {@link Future} instances. Note
 * that, whenever possible, it is strongly preferred to modify those libraries to return {@code
 * ListenableFuture} directly.
 *

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.service;

/**
 * Abstract base class for Fess application services.
 * This class provides common functionality and utilities for service implementations
 * throughout the Fess search application.
 */
public abstract class FessAppService {

    /**
     * Default constructor.
     */
    public FessAppService() {

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.core.text;

/**
 * JSON utilities.
 *
 * @author shinsuke
 *
 */
public class JsonUtil {

    /**
     * Defualt constructor.
     */
    protected JsonUtil() {
    }

    /**
     * Escapes a value as Json string.

│   ├── user/                  # User index
│   ├── exbhv/                 # Extended behaviors (repositories)
│   └── exentity/              # Extended entities (domain models)
├── helper/                    # Cross-cutting utilities
├── crawler/                   # Crawling engine
├── sso/                       # SSO implementations
└── ds/                        # Data store connectors

src/main/resources/

# Alte 403-Authentifizierungsfehler-Statuscodes verwenden { #use-old-403-authentication-error-status-codes }

Vor FastAPI-Version `0.122.0` verwendeten die integrierten Sicherheits-Utilities den HTTP-Statuscode `403 Forbidden`, wenn sie dem Client nach einer fehlgeschlagenen Authentifizierung einen Fehler zurückgaben.