}

    /**
     * Executes an external command with the given parameters.
     * @param commands The command array to execute.
     * @param username The username parameter for the command.
     * @param password The password parameter for the command.
     * @return The exit code of the executed command.
     */
    protected int executeCommand(final String[] commands, final String username, final String password) {

import jakarta.annotation.PostConstruct;

/**
 * Query processor component that handles query filters and commands.
 * This class provides a pipeline for processing Lucene queries by applying
 * a chain of filters and executing registered query commands.
 *
 * <p>The processor maintains a map of query commands indexed by query class names
 * and a list of filters that are applied in order during query processing.</p>
 */

## Project Overview

Fess is an Enterprise Search Server built on OpenSearch. It's a Java-based web application that crawls and indexes documents from various sources and provides full-text search capabilities.

## Development Commands

### Setup
```bash
# Download OpenSearch plugins (required before first build)
mvn antrun:run

# Generate DBFlute source code (when schema changes)
mvn dbflute:download  # One-time setup
mvn dbflute:freegen

import jakarta.annotation.PostConstruct;

/**
 * Command-based thumbnail generator that executes external commands to create thumbnails.
 * Uses external tools through command execution to generate thumbnail images from documents.
 */
public class CommandGenerator extends BaseThumbnailGenerator {
    private static final Logger logger = LogManager.getLogger(CommandGenerator.class);

    /** List of command strings to execute for thumbnail generation. */

### Download and Install/Run

Fess 15.3 is now available and can be downloaded on the [Releases page](https://github.com/codelibs/fess/releases "download"). Downloads come in 3 flavors: deb, rpm, zip.

The following commands show how to use the zip download:

    $ unzip fess-15.3.x.zip
    $ cd fess-15.3.x
    $ ./bin/fess

For more details, see the [Installation Guide](https://fess.codelibs.org/15.3/install/index.html).

### Docker

- Changed `kubectl exec` syntax to require `--` before the command. The form `kubectl exec [POD] [COMMAND]` is no longer supported; use `kubectl exec [POD] -- [COMMAND]` instead. ([#133841](https://github.com/kubernetes/kubernetes/pull/133841), [@yangjunmyfm192085](https://github.com/yangjunmyfm192085))

        lastaEnv = env;
        return this;
    }

    /**
     * Adds a system property to the command list.
     * If the property exists in the system, it uses that value with optional append value.
     * Otherwise, it uses the default value if provided.
     *
     * @param cmdList the command list to add the property to
     * @param name the property name

                            }
                            if (Constants.CRAWLER_PROCESS_COMMAND_THREAD_DUMP.equals(command)) {
                                ThreadDumpUtil.printThreadDump();
                            } else {
                                logger.warn("Unknown process command: command={}", command);
                            }

   */
  @GuardedBy("lock")
  private int runningTasks = 0;

  @GuardedBy("lock")
  private boolean shutdown = false;

  @Override
  public void execute(Runnable command) {
    startTask();
    try {
      command.run();
    } finally {
      endTask();
    }
  }

  @Override
  public boolean isShutdown() {
    synchronized (lock) {
      return shutdown;
    }
  }

- kubeadm: if an unknown command name is passed to any parent command such as 'kubeadm init phase' return an error. If 'kubeadm init phase' or another command that has subcommands is called without subcommand name, print the available commands and also return an error. ([#127096](https://github.com/kubernetes/kubernetes/pull/127096), [@neolit123](https://github.com/neolit123)) [SIG...