HHH-18220 Detect if Application Continuity is enabled for Oracle dialect

hibernate-core/src/main/java/org/hibernate/cfg/DialectSpecificSettings.java

@@ -12,6 +12,7 @@ package org.hibernate.cfg;
  * its underlying JDBC {@link java.sql.Connection}.
  *
  * @author Marco Belladelli
+ * @author Loïc Lefèvre
  */
 public interface DialectSpecificSettings {
 	/**
@@ -28,6 +29,15 @@ public interface DialectSpecificSettings {
 	 */
 	public static final String ORACLE_EXTENDED_STRING_SIZE = "hibernate.dialect.oracle.extended_string_size";
 
+	/**
+	 * Specifies whether this database is accessed using a database service protected by Application Continuity.
+	 *
+	 * @settingDefault {@code false}
+	 *
+	 * @see <a href="https://docs.oracle.com/en/database/oracle/oracle-database/23/jjdbc/application-continuity.html">Application Continuity for Java</a>
+	 */
+	public static final String ORACLE_APPLICATION_CONTINUITY = "hibernate.dialect.oracle.application_continuity";
+
 	/**
 	 * Specifies whether this database's {@code ansinull} setting is enabled.
 	 *

hibernate-core/src/main/java/org/hibernate/dialect/OracleDialect.java

@@ -187,6 +187,9 @@ public class OracleDialect extends Dialect {
 	// Is MAX_STRING_SIZE set to EXTENDED?
 	protected final boolean extended;
 
+	// Is the database accessed using a database service protected by Application Continuity.
+	protected final boolean applicationContinuity;
+
 	protected final int driverMajorVersion;
 
 	protected final int driverMinorVersion;
@@ -200,6 +203,7 @@ public class OracleDialect extends Dialect {
 		super(version);
 		autonomous = false;
 		extended = false;
+		applicationContinuity = false;
 		driverMajorVersion = 19;
 		driverMinorVersion = 0;
 	}
@@ -212,6 +216,7 @@ public class OracleDialect extends Dialect {
 		super( info );
 		autonomous = serverConfiguration.isAutonomous();
 		extended = serverConfiguration.isExtended();
+		applicationContinuity = serverConfiguration.isApplicationContinuity();
 		this.driverMinorVersion = serverConfiguration.getDriverMinorVersion();
 		this.driverMajorVersion = serverConfiguration.getDriverMajorVersion();
 	}
@@ -258,6 +263,10 @@ public class OracleDialect extends Dialect {
 		return extended;
 	}
 
+	public boolean isApplicationContinuity() {
+		return applicationContinuity;
+	}
+
 	@Override
 	protected DatabaseVersion getMinimumSupportedVersion() {
 		return MINIMUM_VERSION;

hibernate-core/src/main/java/org/hibernate/dialect/OracleServerConfiguration.java

@@ -6,15 +6,20 @@
  */
 package org.hibernate.dialect;
 
+import java.sql.Connection;
 import java.sql.DatabaseMetaData;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.List;
 
+import oracle.jdbc.replay.ReplayStatistics;
+import oracle.jdbc.replay.ReplayableConnection;
 import org.hibernate.engine.jdbc.dialect.spi.DialectResolutionInfo;
 import org.hibernate.internal.util.config.ConfigurationHelper;
 
+import static oracle.jdbc.replay.ReplayableConnection.StatisticsReportType.FOR_CURRENT_CONNECTION;
+import static org.hibernate.cfg.DialectSpecificSettings.ORACLE_APPLICATION_CONTINUITY;
 import static org.hibernate.cfg.DialectSpecificSettings.ORACLE_AUTONOMOUS_DATABASE;
 import static org.hibernate.cfg.DialectSpecificSettings.ORACLE_EXTENDED_STRING_SIZE;
 
@@ -22,10 +27,12 @@ import static org.hibernate.cfg.DialectSpecificSettings.ORACLE_EXTENDED_STRING_S
  * Utility class that extract some initial configuration from the database for {@link OracleDialect}.
  *
  * @author Marco Belladelli
+ * @author Loïc Lefèvre
  */
 public class OracleServerConfiguration {
 	private final boolean autonomous;
 	private final boolean extended;
+	private final boolean applicationContinuity;
 	private final int driverMajorVersion;
 	private final int driverMinorVersion;
 
@@ -37,6 +44,10 @@ public class OracleServerConfiguration {
 		return extended;
 	}
 
+	public boolean isApplicationContinuity() {
+		return applicationContinuity;
+	}
+
 	public int getDriverMajorVersion() {
 		return driverMajorVersion;
 	}
@@ -46,7 +57,7 @@ public class OracleServerConfiguration {
 	}
 
 	public OracleServerConfiguration(boolean autonomous, boolean extended) {
-		this( autonomous, extended, 19, 0 );
+		this( autonomous, extended, false, 19, 0 );
 	}
 
 	public OracleServerConfiguration(
@@ -54,8 +65,18 @@ public class OracleServerConfiguration {
 			boolean extended,
 			int driverMajorVersion,
 			int driverMinorVersion) {
+		this(autonomous, extended, false, driverMajorVersion, driverMinorVersion);
+	}
+		
+	public OracleServerConfiguration(
+			boolean autonomous,
+			boolean extended,
+			boolean applicationContinuity,
+			int driverMajorVersion,
+			int driverMinorVersion) {
 		this.autonomous = autonomous;
 		this.extended = extended;
+		this.applicationContinuity = applicationContinuity;
 		this.driverMajorVersion = driverMajorVersion;
 		this.driverMinorVersion = driverMinorVersion;
 	}
@@ -63,6 +84,7 @@ public class OracleServerConfiguration {
 	public static OracleServerConfiguration fromDialectResolutionInfo(DialectResolutionInfo info) {
 		Boolean extended = null;
 		Boolean autonomous = null;
+		Boolean applicationContinuity = null;
 		Integer majorVersion = null;
 		Integer minorVersion = null;
 		final DatabaseMetaData databaseMetaData = info.getDatabaseMetadata();
@@ -70,7 +92,42 @@ public class OracleServerConfiguration {
 			majorVersion = databaseMetaData.getDriverMajorVersion();
 			minorVersion = databaseMetaData.getDriverMinorVersion();
 
-			try (final Statement statement = databaseMetaData.getConnection().createStatement()) {
+
+			try {
+				final Connection c = databaseMetaData.getConnection();
+
+				// Use Oracle JDBC replay statistics information to determine if this
+				// connection is protected by Application Continuity
+				try {
+					final ReplayableConnection re = (ReplayableConnection) c;
+					ReplayStatistics stats = re.getReplayStatistics(FOR_CURRENT_CONNECTION);
+
+					final long totalRequests = stats.getTotalRequests();
+					final long protectedCalls = stats.getTotalProtectedCalls();
+
+					try (final Statement s = c.createStatement()) {
+						try (final ResultSet r = s.executeQuery("select 1 from dual")) {
+							r.next();
+						}
+					}
+
+					stats = re.getReplayStatistics(FOR_CURRENT_CONNECTION);
+
+					// Application continuity is enabled on this database service if the number of
+					// total requests and the number of protected calls for this connection have
+					// both increased.
+					applicationContinuity = stats.getTotalRequests() > totalRequests && stats.getTotalProtectedCalls() > protectedCalls;
+				}
+				catch(Exception e) {
+					// A ClassCastException or a NullPointerException are expected here in the case
+					// the Connection Factory is not the right one (not Replayable: ClassCastException)
+					// or if the database service has not been configured (server side) to enable
+					// application continuity (NullPointerException).
+					applicationContinuity = false;
+				}
+
+				// continue the checks...
+				try (final Statement statement = c.createStatement()) {
 					final ResultSet rs = statement.executeQuery(
 							"select cast('string' as varchar2(32000)), " +
 									"sys_context('USERENV','CLOUD_SERVICE') from dual"
@@ -81,6 +138,7 @@ public class OracleServerConfiguration {
 						autonomous = isAutonomous(rs.getString(2));
 					}
 				}
+			}
 			catch (SQLException ex) {
 				// failed, so MAX_STRING_SIZE == STANDARD, still need to check autonomous
 				extended = false;
@@ -102,6 +160,13 @@ public class OracleServerConfiguration {
 					false
 			);
 		}
+		if ( applicationContinuity == null ) {
+			applicationContinuity = ConfigurationHelper.getBoolean(
+					ORACLE_APPLICATION_CONTINUITY,
+					info.getConfigurationValues(),
+					false
+			);
+		}
 		if ( majorVersion == null ) {
 			try {
 				java.sql.Driver driver = java.sql.DriverManager.getDriver( "jdbc:oracle:thin:" );
@@ -114,7 +179,7 @@ public class OracleServerConfiguration {
 			}
 
 		}
-		return new OracleServerConfiguration( autonomous, extended, majorVersion, minorVersion );
+		return new OracleServerConfiguration( autonomous, extended, applicationContinuity, majorVersion, minorVersion );
 	}
 
 	private static boolean isAutonomous(String cloudServiceParam) {