import org.codelibs.fess.opensearch.user.exentity.User;

/**
 * Interface for authentication chain operations.
 * Provides methods for user management and authentication operations.
 */
public interface AuthenticationChain {

    /**
     * Updates an existing user in the authentication chain.
     * @param user The user to update.
     */
    void update(User user);

    /**

    public User load(final User user) {
        User u = user;
        for (final AuthenticationChain chain : chains) {
            u = chain.load(u);
        }
        return u;
    }

    /**
     * Adds an authentication chain to the manager.
     * @param chain The authentication chain to add.
     */
    public void addChain(final AuthenticationChain chain) {
        chains = ArrayUtils.addAll(chains, chain);
    }

    /**

import org.codelibs.fess.opensearch.user.exentity.User;
import org.codelibs.fess.util.ComponentUtil;

/**
 * An authentication chain for LDAP.
 */
public class LdapChain implements AuthenticationChain {

    /**
     * Default constructor.
     */
    public LdapChain() {
        // do nothing
    }

    @Override
    public void update(final User user) {

 * Provides user management through command-line tool execution for password changes and user deletion.
 */
public class CommandChain implements AuthenticationChain {

    private static final Logger logger = LogManager.getLogger(CommandChain.class);

    /** Working directory for command execution. */
    protected File workingDirectory = null;