│   ├── 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

 * 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() {

# ==============================================================================
#
# macOS specific setup for all TF scripts.
#

# Mac version of Core utilities differ in usage. Since our scripts are written
# with the GNU style, we need to set GNU utilities to be default on Mac.
if [[ -n "$(which grealpath)" ]] &&  [[ -n "$(which gstat)" ]]; then
  alias realpath=grealpath
  alias stat=gstat

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.

 * 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.

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.
 *

 * this could be a factory, generator, builder, closure, or something else entirely. No guarantees
 * are implied by this interface.
 *
 * <p>The {@link Suppliers} class provides common suppliers and related utilities.
 *
 * <p>As this interface extends {@code java.util.function.Supplier}, an instance of this type can be
 * used as a {@code java.util.function.Supplier} directly. To use a {@code

import org.jspecify.annotations.Nullable;

/**
 * Legacy version of {@link java.util.function.Function java.util.function.Function}.
 *
 * <p>The {@link Functions} class provides common functions and related utilities.
 *
 * <p>As this interface extends {@code java.util.function.Function}, an instance of this type can be
 * used as a {@code java.util.function.Function} directly. To use a {@code

///

/// info

In this example we use invented custom headers `X-Key` and `X-Token`.

But in real cases, when implementing security, you would get more benefits from using the integrated [Security utilities (the next chapter)](../security/index.md){.internal-link target=_blank}.

///

## Dependencies errors and return values { #dependencies-errors-and-return-values }

import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.junit.jupiter.MockitoExtension;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Base test class providing common test infrastructure and utilities.
 * All test classes should extend this to ensure consistent test setup.
 */
@ExtendWith(MockitoExtension.class)
public abstract class BaseTest {

    protected final Logger logger = LoggerFactory.getLogger(getClass());