/**
 * Pager for duplicate host management with standard paging functionality.
 * This class provides pagination support for duplicate host listings in the admin interface,
 * including navigation controls and search/filter parameters.
 *
 * <p>Duplicate hosts allow administrators to define hostname patterns that should
 * be treated as equivalent during crawling, helping to avoid duplicate content

import org.lastaflute.web.Execute;
import org.lastaflute.web.response.JsonResponse;

import jakarta.annotation.Resource;

/**
 * API action for admin duplicate host management.
 * Provides RESTful API endpoints for managing duplicate host settings in the Fess search engine.
 * Duplicate host settings help prevent indexing the same content from multiple similar URLs.
 *
 */
public class ApiAdminDuplicatehostAction extends FessApiAdminAction {

    /**
     * Displays the initial duplicate host management page.
     *
     * @param form the search form
     * @return HTML response for the duplicate host list page
     */
    @Execute
    @Secured({ ROLE, ROLE + VIEW })
    public HtmlResponse index(final SearchForm form) {
        return asListHtml();
    }

    /**
     * Displays the duplicate host list with pagination.
     *

    E duplicate = arrayAndDuplicate.duplicate;

    int firstIndex = getList().indexOf(duplicate);
    int initialSize = getList().size();
    assertTrue("remove(present) should return true", getList().remove(duplicate));
    assertTrue(
        "After remove(duplicate), a list should still contain the duplicate element",
        getList().contains(duplicate));
    assertFalse(

single process running those previous steps *even* if afterwards, you start **multiple processes** (multiple workers) for the application itself. If those steps were run by **multiple processes**, they would **duplicate** the work by running it in **parallel**, and if the steps were something delicate like a database migration, they could cause conflicts with each other.

Of course, there are some cases where there's no problem in running the previous steps multiple times, in that case, it's...

import jakarta.validation.constraints.Min;
import jakarta.validation.constraints.Size;

/**
 * Form class for creating new duplicate host configuration entries.
 * This form handles the creation of duplicate host mappings that redirect
 * crawling from duplicate hostnames to the regular canonical hostname.
 */
public class CreateForm {

    /**
     * Creates a new CreateForm instance.
     */

import jakarta.validation.constraints.Size;

/**
 * Form class for editing duplicate host configurations in the admin interface.
 * This form extends CreateForm to include fields necessary for updating existing duplicate host entries,
 * including tracking information for optimistic locking and audit trails.
 * Duplicate hosts are used to define which domains should be treated as the same site for crawling purposes.
 *
 */

    collection = getSubjectGenerator().create(arrayAndDuplicate.elements);
    E duplicate = arrayAndDuplicate.duplicate;

    assertTrue(
        "removeAll(intersectingCollection) should return true",
        getList().removeAll(MinimalCollection.of(duplicate)));
    assertFalse(
        "after removeAll(e), a collection should not contain e even "

    collection = getSubjectGenerator().create(arrayAndDuplicate.elements);
    E duplicate = arrayAndDuplicate.duplicate;

    assertTrue(
        "removeAll(intersectingCollection) should return true",
        getList().removeAll(MinimalCollection.of(duplicate)));
    assertFalse(
        "after removeAll(e), a collection should not contain e even "

import org.codelibs.fess.app.web.api.admin.BaseSearchBody;

/**
 * Search request body for duplicate host administration.
 * Extends BaseSearchBody with duplicate host-specific search parameters.
 */
public class SearchBody extends BaseSearchBody {

    /** The regular host name to search for. */
    public String regularName;

    /** The duplicate host name to search for. */
    public String duplicateHostName;

    /**