[GitHub] [arrow] jduo commented on a change in pull request #12254: ARROW-15452: [FlightRPC][Java] JDBC driver for Flight SQL

[GitBox <gi...@apache.org>]

jduo commented on a change in pull request #12254:
URL: https://github.com/apache/arrow/pull/12254#discussion_r824962459



##########
File path: java/flight/flight-jdbc-driver/src/main/java/org/apache/arrow/driver/jdbc/ArrowFlightJdbcDriver.java
##########
@@ -0,0 +1,253 @@
+/*
+ * 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.arrow.driver.jdbc;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.sql.SQLException;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Properties;
+
+import org.apache.arrow.driver.jdbc.utils.ArrowFlightConnectionConfigImpl.ArrowFlightConnectionProperty;
+import org.apache.arrow.flight.FlightRuntimeException;
+import org.apache.arrow.memory.RootAllocator;
+import org.apache.arrow.util.Preconditions;
+import org.apache.calcite.avatica.AvaticaConnection;
+import org.apache.calcite.avatica.DriverVersion;
+import org.apache.calcite.avatica.Meta;
+import org.apache.calcite.avatica.UnregisteredDriver;
+import org.apache.calcite.avatica.org.apache.http.NameValuePair;
+import org.apache.calcite.avatica.org.apache.http.client.utils.URLEncodedUtils;
+
+/**
+ * JDBC driver for querying data from an Apache Arrow Flight server.
+ */
+public class ArrowFlightJdbcDriver extends UnregisteredDriver {
+
+  private static final String CONNECT_STRING_PREFIX = "jdbc:arrow-flight://";
+  private static DriverVersion version;
+
+  static {
+    // Special code for supporting Java9 and higher.
+    // Netty requires some extra properties to unlock some native memory management api
+    // Setting this property if not already set externally
+    // This has to be done before any netty class is being loaded
+    final String key = "cfjd.io.netty.tryReflectionSetAccessible";
+    final String tryReflectionSetAccessible = System.getProperty(key);
+    if (tryReflectionSetAccessible == null) {
+      System.setProperty(key, Boolean.TRUE.toString());
+    }
+
+    new ArrowFlightJdbcDriver().register();
+  }
+
+  @Override
+  public ArrowFlightConnection connect(final String url, final Properties info)
+      throws SQLException {
+    final Properties properties = new Properties(info);
+    properties.putAll(info);
+
+    if (url != null) {
+      final Map<Object, Object> propertiesFromUrl = getUrlsArgs(url);
+      properties.putAll(propertiesFromUrl);
+    }
+
+    try {
+      return ArrowFlightConnection.createNewConnection(
+          this,
+          factory,
+          url,
+          properties,
+          new RootAllocator(Long.MAX_VALUE));
+    } catch (AssertionError | FlightRuntimeException e) {
+      throw new SQLException("Failed to connect.", e);
+    }
+  }
+
+  @Override
+  protected String getFactoryClassName(final JdbcVersion jdbcVersion) {
+    return ArrowFlightJdbcFactory.class.getName();
+  }
+
+  @Override
+  protected DriverVersion createDriverVersion() {
+
+    CreateVersionIfNull:
+    {
+
+      if (version != null) {
+        break CreateVersionIfNull;
+      }
+
+      try (Reader reader = new BufferedReader(new InputStreamReader(
+          this.getClass().getResourceAsStream("/properties/flight.properties"),
+          StandardCharsets.UTF_8))) {
+        final Properties properties = new Properties();
+        properties.load(reader);
+
+        final String parentName = properties
+            .getProperty("org.apache.arrow.flight.name");
+        final String parentVersion = properties
+            .getProperty("org.apache.arrow.flight.version");
+        final String[] pVersion = parentVersion.split("\\.");
+
+        final int parentMajorVersion = Integer.parseInt(pVersion[0]);
+        final int parentMinorVersion = Integer.parseInt(pVersion[1]);
+
+        final String childName = properties
+            .getProperty("org.apache.arrow.flight.jdbc-driver.name");
+        final String childVersion = properties
+            .getProperty("org.apache.arrow.flight.jdbc-driver.version");
+        final String[] cVersion = childVersion.split("\\.");
+
+        final int childMajorVersion = Integer.parseInt(cVersion[0]);
+        final int childMinorVersion = Integer.parseInt(cVersion[1]);
+
+        version = new DriverVersion(childName, childVersion, parentName,
+            parentVersion, true, childMajorVersion, childMinorVersion,
+            parentMajorVersion, parentMinorVersion);
+      } catch (final IOException e) {
+        throw new RuntimeException("Failed to load driver version.", e);
+      }
+    }
+
+    return version;
+  }
+
+  @Override
+  public Meta createMeta(final AvaticaConnection connection) {
+    return new ArrowFlightMetaImpl((ArrowFlightConnection) connection);
+  }
+
+  @Override
+  protected String getConnectStringPrefix() {
+    return CONNECT_STRING_PREFIX;
+  }
+
+  @Override
+  public boolean acceptsURL(final String url) throws SQLException {
+    return Preconditions.checkNotNull(url).startsWith(CONNECT_STRING_PREFIX);
+  }
+
+  /**
+   * Parses the provided url based on the format this driver accepts, retrieving
+   * arguments after the {@link #CONNECT_STRING_PREFIX}.
+   * <p>
+   * This method gets the args if the provided URL follows this pattern:
+   * {@code jdbc:arrow-flight://<host>:<port>[/?key1=val1&key2=val2&(...)]}
+   *
+   * <table border="1">
+   *    <tr>
+   *        <td>Group</td>
+   *        <td>Definition</td>
+   *        <td>Value</td>
+   *    </tr>
+   *    <tr>
+   *        <td>? — inaccessible</td>
+   *        <td>{@link #getConnectStringPrefix}</td>
+   *        <td>
+   *            the URL prefix accepted by this driver, i.e.,
+   *            {@code "jdbc:arrow-flight://"}
+   *        </td>
+   *    </tr>
+   *    <tr>
+   *        <td>1</td>
+   *        <td>IPv4 host name</td>
+   *        <td>
+   *            first word after previous group and before "{@code :}"
+   *        </td>
+   *    </tr>
+   *    <tr>
+   *        <td>2</td>
+   *        <td>IPv4 port number</td>
+   *        <td>
+   *            first number after previous group and before "{@code /?}"
+   *        </td>
+   *    </tr>
+   *    <tr>
+   *        <td>3</td>
+   *        <td>custom call parameters</td>
+   *        <td>
+   *            all parameters provided after "{@code /?}" — must follow the
+   *            pattern: "{@code key=value}" with "{@code &}" separating a
+   *            parameter from another
+   *        </td>
+   *    </tr>
+   * </table>
+   *
+   * @param url The url to parse.
+   * @return the parsed arguments.
+   * @throws SQLException If an error occurs while trying to parse the URL.
+   */
+  private Map<Object, Object> getUrlsArgs(String url)
+      throws SQLException {
+
+    /*
+     *
+     * Perhaps this logic should be inside a utility class, separated from this
+     * one, so as to better delegate responsibilities and concerns throughout
+     * the code and increase maintainability.
+     *
+     * =====
+     *
+     * Keep in mind that the URL must ALWAYS follow the pattern:
+     * "jdbc:arrow-flight://<host>:<port>[/?param1=value1&param2=value2&(...)]."
+     *
+     */
+
+    if (!url.startsWith("jdbc:")) {
+      throw new SQLException("Malformed/invalid URL!");
+    }
+
+    // It's necessary to use a string without "jdbc:" at the beginning to be parsed as a valid URL.
+    url = url.substring(5);
+
+    final URI uri;
+
+    try {
+      uri = URI.create(url);
+    } catch (final IllegalArgumentException e) {
+      throw new SQLException("Malformed/invalid URL!", e);
+    }
+
+    if (!Objects.equals(uri.getScheme(), "arrow-flight")) {

Review comment:
       TLS is enabled using the useTls connection property (so we'd generate a grpc+tls scheme).
   I propose that we treat the scheme as optional, with as grpc, but also allow explicit setting of known schemes (grpc+unix, ucx)




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org