- **Data Persistence**: Multiple backend options including OpenSearch integration

## Technology Stack

- **Java**: 21+ (requires Java 21 or higher)
- **Build System**: Maven 3.x
- **DI Container**: LastaFlute DI
- **HTTP Client**: Apache HttpComponents
- **Content Extraction**: Apache Tika, Apache POI, PDFBox
- **Testing**: JUnit 4, UTFlute, Testcontainers
- **Storage Backends**: OpenSearch, Memory-based

## Quick Start

 */
class TaskRunner(
  val backend: Backend,
  internal val logger: Logger = TaskRunner.logger,
) : Lockable {
  private var nextQueueName = 10000
  private var coordinatorWaiting = false
  private var coordinatorWakeUpAt = 0L

  /**
   * When we need a new thread to run tasks, we call [Backend.execute]. A few microseconds later we

    if (isLoom()) {
      val backend = TaskRunner.RealBackend(loomThreadFactory())
      val taskRunner = TaskRunner(backend)

      OkHttpClient
        .Builder()
        .connectionPool(
          buildConnectionPool(
            connectionListener = connectionListener,
            taskRunner = taskRunner,
          ),
        ).dispatcher(Dispatcher(backend.executor))
        .taskRunnerInternal(taskRunner)

import org.lastaflute.web.validation.Required;

/**
 * Form for uploading files to the storage system via the admin API.
 * This form is used in the admin API interface to upload files to the storage backend
 * with optional path specification for file organization.
 */
public class UploadForm {

    /**
     * The storage path where the file should be uploaded.

## Architecture

### Module Structure

```
fess-crawler-parent/
├── fess-crawler/              # Core framework
├── fess-crawler-lasta/        # LastaFlute DI integration
└── fess-crawler-opensearch/   # OpenSearch backend
```

### Key Design Patterns

**Factory**: `CrawlerClientFactory`, `ExtractorFactory` - protocol/format-specific component selection
**Strategy**: `CrawlerClient`, `Extractor`, `Transformer` - pluggable implementations

   * default initial capacity and load factor.
   */
  public static <B extends @Nullable Object> MutableClassToInstanceMap<B> create() {
    return new MutableClassToInstanceMap<>(new HashMap<Class<? extends @NonNull B>, B>());
  }

  /**
   * Returns a new {@code MutableClassToInstanceMap} instance backed by a given empty {@code

      other[size] = null;
    }
    copyIntoArray(other, 0);
    return other;
  }

  /** If this collection is backed by an array of its elements in insertion order, returns it. */
  @Nullable Object @Nullable [] internalArray() {
    return null;
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements start.
   */

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.annotations.VisibleForTesting;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableList} backed by a simple array.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableList<E> extends ImmutableList<E> {

OkCurl
======

_A curl for the next-generation web._

OkCurl is an OkHttp-backed curl clone which allows you to test OkHttp's HTTP engine (including
HTTP/2) against web servers.

To run locally, make sure you have GRAALVM_HOME set and run

```bash
./okcurl

import java.util.Collection;
import java.util.EnumSet;
import java.util.Spliterator;
import java.util.function.Consumer;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} backed by a non-empty {@link java.util.EnumSet}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@SuppressWarnings("serial") // we're overriding default serialization