@SuppressLint("NewApi")
  override fun getSelectedProtocol(sslSocket: SSLSocket): String? =
    try {
      // SSLSocket.getApplicationProtocol returns "" if application protocols values will not
      // be used. Observed if you didn't specify SSLParameters.setApplicationProtocols
      when (val protocol = sslSocket.applicationProtocol) {
        null, "" -> null
        else -> protocol
      }

但也可以使用其它备选 `servers`，例如，需要同一个 API 文档与 staging 和生产环境交互。

如果传递自定义 `servers` 列表，并有 `root_path`（ 因为 API 使用了代理），**FastAPI** 会在列表开头使用这个 `root_path` 插入**服务器**。

例如：

{* ../../docs_src/behind_a_proxy/tutorial003.py hl[4:7] *}

这段代码生产如下 OpenAPI 概图：

```JSON hl_lines="5-7"
{
    "openapi": "3.0.2",
    // More stuff here
    "servers": [
        {
            "url": "/api/v1"

    /**
     * This filter can be considerably more efficient than other file filters
     * as the specified wildcard and attributes are passed to the server for
     * filtering there (although attributes are largely ignored by servers
     * they are filtered locally by the default accept method).
     *
     * @param wildcard the wildcard pattern for matching file names (e.g., "*.txt")

 */
public enum WitnessServiceType {
    /**
     * Cluster-aware witness service for general cluster resources
     */
    CLUSTER_WITNESS,

    /**
     * Individual file server witness for standalone servers
     */
    FILE_SERVER_WITNESS,

    /**
     * Scale-out file server witness for scale-out deployments
     */
    SCALE_OUT_WITNESS,

    /**

 * under the License.
 */
package org.apache.maven.execution;

import org.apache.maven.lifecycle.LifecycleExecutionException;

/**
 * <p>
 * Extension point that allows build extensions observe and possibly veto project build execution.
 * </p>
 * <strong>Note:</strong> This interface is part of work in progress and can be changed or removed without notice.
 *
 * @see ExecutionListener
 * @see MojoExecutionListener

  // * Future completion can be observed if the waitersField field contains a TOMBSTONE

  // Timed Get
  // There are a few design constraints to consider
  // * We want to be responsive to small timeouts, unpark() has non trivial latency overheads (I
  //   have observed 12 micros on 64-bit linux systems to wake up a parked thread). So if the

      <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
    </proxy>
    -->
  </proxies>

  <!-- servers
   | This is a list of authentication profiles, keyed by the server-id used within the system.
   | Authentication profiles can be used whenever maven must make a connection to a remote server.
   |-->
  <servers>
    <!-- server

                    }
                },
                "summary": "Read Sub",
                "operationId": "read_sub_sub_get",
            }
        }
    },
    "servers": [{"url": "/subapi"}],
}


def test_openapi_schema_main():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == openapi_schema_main

        return 0;
    }

    @Override
    int readParametersWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        // observed two zero bytes here with at least win98
        return 2;
    }

    @Override
    int readDataWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        return switch (informationLevel) {

    Typically this would cause certain redirects to fail in debug and development configurations.


## Version 4.4.0

_2020-02-17_

 *  New: Support `canceled()` as an event that can be observed by `EventListener`. This should be
    useful for splitting out canceled calls in metrics.

 *  New: Publish a [bill of materials (BOM)][bom] for OkHttp. Depend on this from Gradle or Maven to