core/src/main/java/org/apache/calcite/avatica/remote/AvaticaHttpClientFactoryImpl.java

/*
 * 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
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.calcite.avatica.remote;

import org.apache.calcite.avatica.ConnectionConfig;

import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManager;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.lang.reflect.Constructor;
import java.net.URL;
import java.util.Objects;

/**
 * Default implementation of {@link AvaticaHttpClientFactory} which chooses an implementation
 * from a property.
 */
public class AvaticaHttpClientFactoryImpl implements AvaticaHttpClientFactory {
  private static final Logger LOG = LoggerFactory.getLogger(AvaticaHttpClientFactoryImpl.class);

  public static final String HTTP_CLIENT_IMPL_DEFAULT =
      AvaticaCommonsHttpClientImpl.class.getName();

  // Public for Type.PLUGIN
  public static final AvaticaHttpClientFactoryImpl INSTANCE = new AvaticaHttpClientFactoryImpl();

  // Public for Type.PLUGIN
  public AvaticaHttpClientFactoryImpl() {}

  /**
   * Returns a singleton instance of {@link AvaticaHttpClientFactoryImpl}.
   *
   * @return A singleton instance.
   */
  public static AvaticaHttpClientFactoryImpl getInstance() {
    return INSTANCE;
  }

  @Override public AvaticaHttpClient getClient(URL url, ConnectionConfig config,
      KerberosConnection kerberosUtil) {
    String className = config.httpClientClass();
    if (null == className) {
      className = HTTP_CLIENT_IMPL_DEFAULT;
    }

    AvaticaHttpClient client = instantiateClient(className, url);

    if (client instanceof HttpClientPoolConfigurable) {
      PoolingHttpClientConnectionManager pool = CommonsHttpClientPoolCache.getPool(config);
      ((HttpClientPoolConfigurable) client).setHttpClientPool(pool);
    } else {
      // Kept for backwards compatibility, the current AvaticaCommonsHttpClientImpl
      // does not implement these interfaces
      if (client instanceof TrustStoreConfigurable) {
        File truststore = config.truststore();
        String truststorePassword = config.truststorePassword();
        if (null != truststore && null != truststorePassword) {
          ((TrustStoreConfigurable) client).setTrustStore(truststore, truststorePassword);
        }
      } else {
        LOG.debug("{} is not capable of SSL/TLS communication", client.getClass().getName());
      }

      if (client instanceof KeyStoreConfigurable) {
        File keystore = config.keystore();
        String keystorePassword = config.keystorePassword();
        String keyPassword = config.keyPassword();
        if (null != keystore && null != keystorePassword && null != keyPassword) {
          ((KeyStoreConfigurable) client).setKeyStore(keystore, keystorePassword, keyPassword);
        }
      } else {
        LOG.debug("{} is not capable of Mutual authentication", client.getClass().getName());
      }

      // Set the SSL hostname verification if the client supports it
      if (client instanceof HostnameVerificationConfigurable) {
        ((HostnameVerificationConfigurable) client)
            .setHostnameVerification(config.hostnameVerification());
      } else {
        LOG.debug("{} is not capable of configurable SSL/TLS hostname verification",
            client.getClass().getName());
      }
    }

    final String authString = config.authentication();
    final AuthenticationType authType = authString == null ? null
        : AuthenticationType.valueOf(authString);

    if (client instanceof UsernamePasswordAuthenticateable) {
      if (isUserPasswordAuth(authType)) {

        final String username = config.avaticaUser();
        final String password = config.avaticaPassword();

        // Can't authenticate with NONE or w/o username and password
        if (null != username && null != password) {
          ((UsernamePasswordAuthenticateable) client)
              .setUsernamePassword(authType, username, password);
        } else {
          LOG.debug("Username or password was null");
        }
      }
    } else {
      LOG.debug("{} is not capable of username/password authentication.", authType);
    }

    if (client instanceof GSSAuthenticateable) {
      if (AuthenticationType.SPNEGO == authType) {
        // The actual principal is set in DoAsAvaticaHttpClient below
        ((GSSAuthenticateable) client).setGSSCredential(null);
      }
    } else {
      LOG.debug("{} is not capable of kerberos authentication.", authType);
    }

    if (null != kerberosUtil) {
      client = new DoAsAvaticaHttpClient(client, kerberosUtil);
    }

    return client;
  }

  private AvaticaHttpClient instantiateClient(String className, URL url) {
    AvaticaHttpClient client = null;
    Exception clientCreationException = null;
    try {
      // Ensure that the given class is actually a subclass of AvaticaHttpClient
      Class<? extends AvaticaHttpClient> clz =
          Class.forName(className).asSubclass(AvaticaHttpClient.class);
      Constructor<? extends AvaticaHttpClient> constructor = clz.getConstructor(URL.class);
      client = constructor.newInstance(Objects.requireNonNull(url));
    } catch (Exception e) {
      clientCreationException = e;
    }

    if (client == null) {
      throw new RuntimeException("Failed to construct AvaticaHttpClient implementation "
          + className, clientCreationException);
    } else {
      return client;
    }
  }

  private boolean isUserPasswordAuth(AuthenticationType authType) {
    return AuthenticationType.BASIC == authType || AuthenticationType.DIGEST == authType;
  }
}

// End AvaticaHttpClientFactoryImpl.java