content: /*
   ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
   ~                                                                               ~
   ~ The MIT License (MIT)                                                         ~
   ~                                                                               ~
   ~ Copyright (c) 2015-2025 miaixz.org and other contributors.                    ~
   ~                                                                               ~
   ~ Permission is hereby granted, free of charge, to any person obtaining a copy  ~
   ~ of this software and associated documentation files (the "Software"), to deal ~
   ~ in the Software without restriction, including without limitation the rights  ~
   ~ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell     ~
   ~ copies of the Software, and to permit persons to whom the Software is         ~
   ~ furnished to do so, subject to the following conditions:                      ~
   ~                                                                               ~
   ~ The above copyright notice and this permission notice shall be included in    ~
   ~ all copies or substantial portions of the Software.                           ~
   ~                                                                               ~
   ~ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR    ~
   ~ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,      ~
   ~ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE   ~
   ~ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER        ~
   ~ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, ~
   ~ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN     ~
   ~ THE SOFTWARE.                                                                 ~
   ~                                                                               ~
   ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
  */
  package org.miaixz.bus.http.accord;
  
  import java.io.IOException;
  import java.io.InterruptedIOException;
  import java.net.ProtocolException;
  import java.net.UnknownServiceException;
  import java.security.cert.CertificateException;
  import java.util.Arrays;
  import java.util.List;
  
  import javax.net.ssl.SSLException;
  import javax.net.ssl.SSLHandshakeException;
  import javax.net.ssl.SSLPeerUnverifiedException;
  import javax.net.ssl.SSLSocket;
  
  import org.miaixz.bus.http.metric.Internal;
  
  /**
   * 处理连接规范回退策略:当安全套接字连接由于握手/协议问题而失败时， 可能会使用不同的协议重试连接。实例是有状态的，应该创建并用于单个连接尝试
   *
   * @author Kimi Liu
   * @since Java 17+
   */
  public class ConnectionSelector {
  
      private final List<ConnectionSuite> connectionSuites;
      private int nextModeIndex;
      private boolean isFallbackPossible;
      private boolean isFallback;
  
      public ConnectionSelector(List<ConnectionSuite> connectionSuites) {
          this.nextModeIndex = 0;
          this.connectionSuites = connectionSuites;
      }
  
      /**
       * 根据{@link SSLSocket} 配置连接到指定的主机的信息{@link ConnectionSuite} 返回{@link ConnectionSuite}，不会返回{@code null}
       *
       * @param sslSocket ssl套接字
       * @return 套接字连接的配置
       * @throws IOException 如果套接字不支持任何可用的TLS模式
       */
      public ConnectionSuite configureSecureSocket(SSLSocket sslSocket) throws IOException {
          ConnectionSuite tlsConfiguration = null;
          for (int i = nextModeIndex, size = connectionSuites.size(); i < size; i++) {
              ConnectionSuite connectionSuite = connectionSuites.get(i);
              if (connectionSuite.isCompatible(sslSocket)) {
                  tlsConfiguration = connectionSuite;
                  nextModeIndex = i + 1;
                  break;
              }
          }
  
          if (null == tlsConfiguration) {
              // 这可能是第一次尝试连接，而套接字不支持任何必需的协议
              // 或者可能是重试(但此套接字支持的协议比先前的套接字所建议的少)
              throw new UnknownServiceException(
                      "Unable to find acceptable protocols. isFallback=" + isFallback + ", modes=" + connectionSuites
                              + ", supported protocols=" + Arrays.toString(sslSocket.getEnabledProtocols()));
          }
  
          isFallbackPossible = isFallbackPossible(sslSocket);
  
          Internal.instance.apply(tlsConfiguration, sslSocket, isFallback);
  
          return tlsConfiguration;
      }
  
      /**
       * 报告连接失败。确定下一个要尝试的{@link ConnectionSuite}(如果有的话)
       *
       * @param ex 异常信息
       * @return 如果需要使用 {@link #configureSecureSocket(SSLSocket)} 或{@code false}重试连接，
       *         则为{@code true};如果不需要重试连接，则为{@link #configureSecureSocket(SSLSocket)}或{@code false}
       */
      public boolean connectionFailed(IOException ex) {
          // 未来使用此策略进行连接的任何尝试都将是一次回退尝试
          isFallback = true;
  
          if (!isFallbackPossible) {
              return false;
          }
  
          // 如果有协议问题，不会恢复.
          if (ex instanceof ProtocolException) {
              return false;
          }
  
          // 如果出现中断或超时(SocketTimeoutException)，则不进行恢复。对于套接字连接超时情况，
          // 我们不会使用不同的ConnectionSpec尝试相同的主机:认为通讯是不可到达的
          if (ex instanceof InterruptedIOException) {
              return false;
          }
  
          // 查找已知的客户端或协商错误，这些错误不太可能通过再次尝试使用不同的连接规范来修复
          if (ex instanceof SSLHandshakeException) {
              // 如果问题是来自X509TrustManager的一个证书异常，那么不会重试.
              if (ex.getCause() instanceof CertificateException) {
                  return false;
              }
          }
          if (ex instanceof SSLPeerUnverifiedException) {
              // 例如，证书未经许可的错误.
              return false;
          }
  
          // 重试所有其他SSL失败
          return ex instanceof SSLException;
      }
  
      /**
       * 如果根据提供的{@link SSLSocket}，回退策略中的任何后面的{@link ConnectionSuite} 看起来都是可能的，则返回{@code true}。假设具有与提供的套接字相同的功能
       */
      private boolean isFallbackPossible(SSLSocket socket) {
          for (int i = nextModeIndex; i < connectionSuites.size(); i++) {
              if (connectionSuites.get(i).isCompatible(socket)) {
                  return true;
              }
          }
          return false;
      }
  
  }
  