/**
 * Fess-specific web resource root implementation for Tomcat.
 * This class extends StandardRoot to provide custom web resource handling
 * for Fess plugins, including support for plugin JAR files in the WEB-INF/plugin directory.
 */
public class FessWebResourceRoot extends StandardRoot {
    /** Logger instance for this class */
    private static final Logger logger = Logger.getLogger(FessWebResourceRoot.class.getName());

 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

In this case, you could want to document how that external API *should* look like. What *path operation* it should have, what body it should expect, what response it should return, etc.

## An app with callbacks { #an-app-with-callbacks }

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful

 * Stopwords are common words that should be ignored during search indexing and querying.
 * This form is used in the admin interface to upload custom stopwords dictionary files.
 */
public class UploadForm {

    /**
     * The dictionary ID that identifies which stopwords dictionary configuration to update.
     * This ID corresponds to a specific stopwords dictionary instance in the system.
     */
    @Required

 * Copyright (C) 2000  "Michael B. Allen" <jcifs at samba dot org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,

 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0

# This CITATION.cff file was generated with cffinit.
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cff-version: 1.2.0
title: FastAPI
message: >-
  If you use this software, please cite it using the
  metadata from this file.
type: software
authors:
  - given-names: Sebastián
    family-names: Ramírez
    email: ******@****.***
identifiers:
repository-code: 'https://github.com/fastapi/fastapi'

    private final AtomicInteger called = new AtomicInteger();

    InteractionTester(Class<T> interfaceType, Method method) {
      this.interfaceType = interfaceType;
      this.method = method;
      this.passedArgs = getParameterValues(method);
      this.returnValue = new FreshValueGenerator().generateFresh(method.getReturnType());
    }

    @Override
    protected @Nullable Object handleInvocation(