ARROW-18296: [Java] Honor Driver#connect API contract in JDBC driver (#…

…14617)

Authored-by: David Li <li.davidm96@gmail.com>
Signed-off-by: David Li <li.davidm96@gmail.com>

java/flight/flight-sql-jdbc-driver/src/main/java/org/apache/arrow/driver/jdbc/ArrowFlightJdbcDriver.java

@@ -29,6 +29,7 @@
 import java.sql.SQLException;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Properties;
 
 import org.apache.arrow.driver.jdbc.utils.ArrowFlightConnectionConfigImpl.ArrowFlightConnectionProperty;
@@ -72,7 +73,11 @@ public ArrowFlightConnection connect(final String url, final Properties info)
     properties.putAll(info);
 
     if (url != null) {
-      final Map<Object, Object> propertiesFromUrl = getUrlsArgs(url);
+      final Optional<Map<Object, Object>> maybeProperties = getUrlsArgs(url);
+      if (!maybeProperties.isPresent()) {
+        return null;
+      }
+      final Map<Object, Object> propertiesFromUrl = maybeProperties.get();
       properties.putAll(propertiesFromUrl);
     }
 
@@ -199,11 +204,11 @@ public boolean acceptsURL(final String url) {
    * </table>
    *
    * @param url The url to parse.
-   * @return the parsed arguments.
+   * @return the parsed arguments, or an empty optional if the driver does not handle this URL.
    * @throws SQLException If an error occurs while trying to parse the URL.
    */
   @VisibleForTesting // ArrowFlightJdbcDriverTest
-  Map<Object, Object> getUrlsArgs(String url)
+  Optional<Map<Object, Object>> getUrlsArgs(String url)
       throws SQLException {
 
     /*
@@ -240,8 +245,7 @@ Map<Object, Object> getUrlsArgs(String url)
 
     if (!Objects.equals(uri.getScheme(), "arrow-flight") &&
         !Objects.equals(uri.getScheme(), "arrow-flight-sql")) {
-      throw new SQLException("URL Scheme must be 'arrow-flight'. Expected format: " +
-          CONNECTION_STRING_EXPECTED);
+      return Optional.empty();
     }
 
     if (uri.getHost() == null) {
@@ -258,7 +262,7 @@ Map<Object, Object> getUrlsArgs(String url)
       resultMap.putAll(keyValuePairs);
     }
 
-    return resultMap;
+    return Optional.of(resultMap);
   }
 
   static Properties lowerCasePropertyKeys(final Properties properties) {

java/flight/flight-sql-jdbc-driver/src/test/java/org/apache/arrow/driver/jdbc/ArrowFlightJdbcDriverTest.java

@@ -17,9 +17,11 @@
 
 package org.apache.arrow.driver.jdbc;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.sql.Connection;
 import java.sql.Driver;
@@ -91,17 +93,15 @@ public void testDriverIsRegisteredInDriverManager() throws Exception {
   }
 
   /**
-   * Tests whether the {@link ArrowFlightJdbcDriver} fails when provided with an
+   * Tests whether the {@link ArrowFlightJdbcDriver} returns null when provided with an
    * unsupported URL prefix.
-   *
-   * @throws SQLException If the test passes.
    */
-  @Test(expected = SQLException.class)
+  @Test
   public void testShouldDeclineUrlWithUnsupportedPrefix() throws Exception {
     final Driver driver = new ArrowFlightJdbcDriver();
 
-    driver.connect("jdbc:mysql://localhost:32010", dataSource.getProperties("flight", "flight123"))
-        .close();
+    assertNull(driver.connect("jdbc:mysql://localhost:32010",
+        dataSource.getProperties("flight", "flight123")));
   }
 
   /**
@@ -263,7 +263,8 @@ public void testDriverUrlParsingMechanismShouldReturnTheDesiredArgsFromUrl() thr
     final ArrowFlightJdbcDriver driver = new ArrowFlightJdbcDriver();
 
     final Map<Object, Object> parsedArgs = driver.getUrlsArgs(
-        "jdbc:arrow-flight-sql://localhost:2222/?key1=value1&key2=value2&a=b");
+        "jdbc:arrow-flight-sql://localhost:2222/?key1=value1&key2=value2&a=b")
+        .orElseThrow(() -> new RuntimeException("URL was rejected"));
 
     // Check size == the amount of args provided (scheme not included)
     assertEquals(5, parsedArgs.size());
@@ -284,7 +285,8 @@ public void testDriverUrlParsingMechanismShouldReturnTheDesiredArgsFromUrl() thr
   public void testDriverUrlParsingMechanismShouldReturnTheDesiredArgsFromUrlWithSemicolon() throws Exception {
     final ArrowFlightJdbcDriver driver = new ArrowFlightJdbcDriver();
     final Map<Object, Object> parsedArgs = driver.getUrlsArgs(
-        "jdbc:arrow-flight-sql://localhost:2222/;key1=value1;key2=value2;a=b");
+        "jdbc:arrow-flight-sql://localhost:2222/;key1=value1;key2=value2;a=b")
+        .orElseThrow(() -> new RuntimeException("URL was rejected"));
 
     // Check size == the amount of args provided (scheme not included)
     assertEquals(5, parsedArgs.size());
@@ -305,7 +307,8 @@ public void testDriverUrlParsingMechanismShouldReturnTheDesiredArgsFromUrlWithSe
   public void testDriverUrlParsingMechanismShouldReturnTheDesiredArgsFromUrlWithOneSemicolon() throws Exception {
     final ArrowFlightJdbcDriver driver = new ArrowFlightJdbcDriver();
     final Map<Object, Object> parsedArgs = driver.getUrlsArgs(
-        "jdbc:arrow-flight-sql://localhost:2222/;key1=value1");
+        "jdbc:arrow-flight-sql://localhost:2222/;key1=value1")
+        .orElseThrow(() -> new RuntimeException("URL was rejected"));
 
     // Check size == the amount of args provided (scheme not included)
     assertEquals(3, parsedArgs.size());
@@ -320,16 +323,10 @@ public void testDriverUrlParsingMechanismShouldReturnTheDesiredArgsFromUrlWithOn
     assertEquals(parsedArgs.get("key1"), "value1");
   }
 
-  /**
-   * Tests whether an exception is thrown upon attempting to connect to a
-   * malformed URI.
-   *
-   */
   @Test
-  public void testDriverUrlParsingMechanismShouldThrowExceptionUponProvidedWithMalformedUrl() {
+  public void testDriverUrlParsingMechanismShouldReturnEmptyOptionalForUnknownScheme() throws SQLException {
     final ArrowFlightJdbcDriver driver = new ArrowFlightJdbcDriver();
-    assertThrows(SQLException.class, () -> driver.getUrlsArgs(
-        "jdbc:malformed-url-flight://localhost:2222"));
+    assertFalse(driver.getUrlsArgs("jdbc:malformed-url-flight://localhost:2222").isPresent());
   }
 
   /**
@@ -341,7 +338,8 @@ public void testDriverUrlParsingMechanismShouldThrowExceptionUponProvidedWithMal
   @Test
   public void testDriverUrlParsingMechanismShouldWorkWithIPAddress() throws Exception {
     final ArrowFlightJdbcDriver driver = new ArrowFlightJdbcDriver();
-    final Map<Object, Object> parsedArgs = driver.getUrlsArgs("jdbc:arrow-flight-sql://0.0.0.0:2222");
+    final Map<Object, Object> parsedArgs = driver.getUrlsArgs("jdbc:arrow-flight-sql://0.0.0.0:2222")
+        .orElseThrow(() -> new RuntimeException("URL was rejected"));
 
     // Check size == the amount of args provided (scheme not included)
     assertEquals(2, parsedArgs.size());
@@ -364,7 +362,8 @@ public void testDriverUrlParsingMechanismShouldWorkWithEmbeddedEspecialCharacter
       throws Exception {
     final ArrowFlightJdbcDriver driver = new ArrowFlightJdbcDriver();
     final Map<Object, Object> parsedArgs = driver.getUrlsArgs(
-        "jdbc:arrow-flight-sql://0.0.0.0:2222?test1=test1value&test2%26continue=test2value&test3=test3value");
+        "jdbc:arrow-flight-sql://0.0.0.0:2222?test1=test1value&test2%26continue=test2value&test3=test3value")
+        .orElseThrow(() -> new RuntimeException("URL was rejected"));
 
     // Check size == the amount of args provided (scheme not included)
     assertEquals(5, parsedArgs.size());