* *路径*可以包含 <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#key-expression" class="external-link" target="_blank">OpenAPI 3 表达式</a>（详见下文），可以使用带参数的变量，以及发送至您的 API 的原始请求的部分

### 回调路径表达式

回调*路径*支持包含发送给您的 API 的原始请求的部分的  <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#key-expression" class="external-link" target="_blank">OpenAPI 3 表达式</a>。

本例中是**字符串**：

```Python

	certificate, err := getTLSCert()
	if err != nil {
		return nil, err
	}
	return &certificate, nil
}

func getTLSCert() (tls.Certificate, error) {
	keyPEMBlock := []byte(`-----BEGIN RSA PRIVATE KEY-----
MIIEpAIBAAKCAQEApEkbPrT6wzcWK1W5atQiGptvuBsRdf8MCg4u6SN10QbslA5k
6BYRdZfFeRpwAwYyzkumug6+eBJatDZEd7+0FF86yxB7eMTSiHKRZ5Mi5ZyCFsez
dndknGBeK6I80s1jd5ZsLLuMKErvbNwSbfX+X6d2mBeYW8Scv9N+qYnNrHHHohvX

					values = append(values, clause.Column{Name: dbName}, m.DB.Migrator().FullDataTypeOf(field))
					createTableSQL += ","
				}
			}

			if !hasPrimaryKeyInDataType && len(stmt.Schema.PrimaryFields) > 0 {
				createTableSQL += "PRIMARY KEY ?,"
				primaryKeys := make([]interface{}, 0, len(stmt.Schema.PrimaryFields))

 * It also supports loading default bad words from a file.
 */
public class BadWordSettings {
    private static final Logger logger = LogManager.getLogger(BadWordSettings.class);

    /** Key for bad word settings. */
    public static final String BAD_WORD_SETTINGS_KEY = "badword";

    /** Array settings for bad words. */
    protected ArraySettings arraySettings;

    /** Default bad words. */

        final Pattern pattern = Pattern.compile("(\\$\\{([\\w\\.]+)\\})");
        final Matcher matcher = pattern.matcher(value);
        while (matcher.find()) {
            final String key = matcher.group(2);
            String replacement = System.getProperty(key);
            if (replacement == null) {
                replacement = matcher.group(1);
            }

        return doGetConditionQuery();
    }

    // ===================================================================================
    //                                                                         Primary Key
    //                                                                         ===========
    public DuplicateHostCB acceptPK(String id) {
        assertObjectNotNull("id", id);
        BsDuplicateHostCB cb = this;

        return doGetConditionQuery();
    }

    // ===================================================================================
    //                                                                         Primary Key
    //                                                                         ===========
    public RelatedQueryCB acceptPK(String id) {
        assertObjectNotNull("id", id);
        BsRelatedQueryCB cb = this;

 * Provides functionality for setting and retrieving objects from request attributes,
 * error handling, and validation in web API context.
 */
public final class WebApiUtil {

    /**
     * Request attribute key for storing web API exceptions.
     */
    private static final String WEB_API_EXCEPTION = "webApiException";

    /**
     * Private constructor to prevent instantiation.
     */
    private WebApiUtil() {
    }

///

/// info | Примечание

В этом примере мы используем выдуманные пользовательские заголовки `X-Key` и `X-Token`.

Но в реальных проектах, при внедрении системы безопасности, вы получите больше пользы используя интегрированные [средства защиты (следующая глава)](../security/index.md){.internal-link target=_blank}.

///

/**
 * Represents a hierarchical trace of nested requests within a session, enabling correlation between
 * session events and their originating operations in the application code. The trace structure
 * supports the following key features:
 *
 * <ul>
 *   <li>Maintains parent-child relationships between requests to track operation nesting</li>
 *   <li>Carries contextual data describing the current request or operation</li>