#690 Do not close result set after fetching last row in auto-commit mode

src/docs/asciidoc/release_notes.adoc

@@ -942,6 +942,20 @@ If you find cases where you think Jaybird should not (or on the contrary should)
 
 For more information, see also https://github.com/FirebirdSQL/jaybird/blob/master/devdoc/jdp/jdp-2024-02-create-database-through-jdbc-url.adoc[jdp-2024-02: Create database through JDBC URL^].
 
+[#no-close-after-last]
+=== `ResultSet` in auto-commit no longer closed after last row
+
+In previous Jaybird versions, iterating over a forward-only result set in auto-commit mode would implicitly close the result set after the last row was fetched -- i.e. when `next()` returned `false`.
+This behaviour complied with the JDBC 3.0 requirements, but in JDBC 4.0 this requirement was removed, but the behaviour is still allowed.
+
+In Jaybird 6, this implicit close has been removed.
+In auto-commit mode, a result set will now remain open until explicitly closed using `ResultSet.close()`, when any statement is executed, when the auto-commit mode is disabled, or by the close of the `Statement` or `Connection`.
+
+As a result set close is an auto-commit boundary, this change may delay commit of the active transaction until another action on the connection.
+If you relied on this implicit close for correctness of your application, you may need to add an explicit call to `ResultSet.close()` -- e.g. using try-with-resources.
+
+For more information, see also https://github.com/FirebirdSQL/jaybird/blob/master/devdoc/jdp/jdp-2024-03-do-not-close-result-set-after-last-row-in-auto-commit.adoc[jdp-2024-03: Do not close result set after last row in auto-commit^].
+
 // TODO add major changes
 
 [#other-fixes-and-changes]
@@ -1225,6 +1239,11 @@ If overridden transaction mappings are used, and the default isolation level has
 As a result, switching isolation levels will now also result in read-only transactions, even if the mapping of the other isolation level is defined with `isc_tpb_write`.
 You will need to explicitly call `setReadOnly(false)`, or -- better yet -- do not override transaction mappings with a `isc_tpb_read`, but always use `isc_tpb_write`, and control read-only state only through `setReadOnly`.
 
+[#compat-no-close-after-last]
+=== `ResultSet` in auto-commit no longer closed after last row
+
+For more information, see <<no-close-after-last>>.
+
 // TODO Document compatibility issues
 
 [#removal-of-classes-packages-and-methods-without-deprecation]
@@ -1615,6 +1634,11 @@ replacement is `new SQLExceptionChainBuilder().append(exception)`
 * `FBManagedConnection`
 ** `setReadOnly(boolean)` was renamed to `setTpbReadOnly(boolean)` to reflect what it actually does
 ** `isReadOnly()` was renamed to `isTpbReadOnly()` to reflect what it actually does
+* `FBObjectListener.FetcherListener`
+** `fetcherClosed(FBFetcher)` was removed
+** `allRowsFetched(FBFetcher)` was removed
+* `FBObjectListener.ResultSetListener`
+** `allRowsFetched(ResultSet)` was removed
 
 [#breaking-changes-unlikely]
 === Unlikely breaking changes

src/main/org/firebirdsql/gds/ng/FbStatement.java

@@ -113,7 +113,7 @@ public interface FbStatement extends ExceptionListenable, AutoCloseable {
      * </p>
      *
      * @param transactionEnd
-     *         close is in response to a transaction end or another operation which will close the cursor
+     *         close is in response to a transaction end or another operation which will implicitly close the cursor
      */
     void closeCursor(boolean transactionEnd) throws SQLException;
 

src/main/org/firebirdsql/jdbc/FBObjectListener.java

@@ -39,31 +39,21 @@ private FBObjectListener() {
 
     public interface FetcherListener {
 
-        /**
-         * Notify listener that underlying fetcher is closed.
-         *
-         * @param fetcher
-         *         fetcher that was closed.
-         */
-        void fetcherClosed(FBFetcher fetcher) throws SQLException;
-
-        /**
-         * Notify listener that underlying fetcher fetched all rows.
-         *
-         * @param fetcher
-         *         fetcher that fetched all rows.
-         */
-        void allRowsFetched(FBFetcher fetcher) throws SQLException;
-
         /**
          * Notify listener that underlying row was changed.
+         * <p>
+         * The default implementation does nothing.
+         * </p>
          *
          * @param fetcher
-         *         instance of {@link FBFetcher} that caused this event.
+         *         instance of {@link FBFetcher} that caused this event
          * @param newRow
-         *         new row.
+         *         new row
          */
-        void rowChanged(FBFetcher fetcher, RowValue newRow) throws SQLException;
+        default void rowChanged(FBFetcher fetcher, RowValue newRow) throws SQLException {
+            // do nothing
+        }
+
     }
 
     /**
@@ -73,47 +63,48 @@ public interface ResultSetListener {
 
         /**
          * Notify listener that result set was closed.
+         * <p>
+         * The default implementation does nothing.
+         * </p>
          *
          * @param rs
-         *         result set that was closed.
-         */
-        void resultSetClosed(ResultSet rs) throws SQLException;
-
-        /**
-         * Notify listener that all rows were fetched. This event is used in auto-commit case to tell the statement that
-         * it is completed.
-         *
-         * @param rs
-         *         result set that was completed.
+         *         result set that was closed
          */
-        void allRowsFetched(ResultSet rs) throws SQLException;
+        default void resultSetClosed(ResultSet rs) throws SQLException {
+            // do nothing
+        }
 
         /**
          * Notify listener that execution of some row updating operation started.
+         * <p>
+         * The default implementation does nothing.
+         * </p>
          *
          * @param updater
          *         instance of {@link FirebirdRowUpdater}
-         * @throws SQLException
-         *         if something went wrong.
          */
-        void executionStarted(FirebirdRowUpdater updater) throws SQLException;
+        default void executionStarted(FirebirdRowUpdater updater) throws SQLException {
+            // do nothing
+        }
 
         /**
          * Notify listener that execution of some row updating operation is completed.
+         * <p>
+         * The default implementation does nothing.
+         * </p>
          *
          * @param updater
-         *         instance of {@link FirebirdRowUpdater}.
-         * @throws SQLException
-         *         if something went wrong.
+         *         instance of {@link FirebirdRowUpdater}
          */
-        void executionCompleted(FirebirdRowUpdater updater, boolean success) throws SQLException;
+        default void executionCompleted(FirebirdRowUpdater updater, boolean success) throws SQLException {
+            // do nothing
+        }
+
     }
 
     /**
-     * Implementation of {@link org.firebirdsql.jdbc.FBObjectListener.ResultSetListener} that implements all methods as
-     * empty methods.
+     * Implementation of {@link org.firebirdsql.jdbc.FBObjectListener.ResultSetListener} that does nothing.
      */
-    @SuppressWarnings("java:S1186")
     public static final class NoActionResultSetListener implements ResultSetListener {
 
         private static final ResultSetListener INSTANCE = new NoActionResultSetListener();
@@ -125,18 +116,6 @@ public static ResultSetListener instance() {
         private NoActionResultSetListener() {
         }
 
-        @Override
-        public void resultSetClosed(ResultSet rs) { }
-
-        @Override
-        public void allRowsFetched(ResultSet rs) { }
-
-        @Override
-        public void executionStarted(FirebirdRowUpdater updater) { }
-
-        @Override
-        public void executionCompleted(FirebirdRowUpdater updater, boolean success) { }
-
     }
 
     /**
@@ -149,25 +128,23 @@ public interface StatementListener {
          *
          * @return instance of {@link FBConnection}
          * @throws SQLException
-         *         if something went wrong.
+         *         if something went wrong
          */
         FBConnection getConnection() throws SQLException;
 
         /**
          * Notify listener that statement execution is being started.
          *
          * @param stmt
-         *         statement that is being executed.
-         * @throws SQLException
-         *         if something went wrong.
+         *         statement that is being executed
          */
         void executionStarted(FBStatement stmt) throws SQLException;
 
         /**
          * Notify the listener that statement was closed.
          *
          * @param stmt
-         *         statement that was closed.
+         *         statement that was closed
          */
         void statementClosed(FBStatement stmt) throws SQLException;
 
@@ -184,14 +161,12 @@ public interface StatementListener {
          * Notify the listener that statement is completed and tell whether execution was successful or not.
          *
          * @param stmt
-         *         statement that was completed.
+         *         statement that was completed
          * @param success
-         *         {@code true} if completion was successful.
-         * @throws SQLException
-         *         if an error occurred.
+         *         {@code true} if completion was successful
          */
-        void statementCompleted(FBStatement stmt, boolean success)
-                throws SQLException;
+        void statementCompleted(FBStatement stmt, boolean success) throws SQLException;
+
     }
 
     /**
@@ -201,30 +176,39 @@ public interface BlobListener {
 
         /**
          * Notify listener that execution of some BLOB operation had been started.
+         * <p>
+         * The default implementation does nothing.
+         * </p>
          *
          * @param blob
-         *         instance of {@link FirebirdBlob} that caused this event.
+         *         instance of {@link FirebirdBlob} that caused this event
          * @throws SQLException
-         *         if something went wrong.
+         *         if something went wrong
          */
-        void executionStarted(FirebirdBlob blob) throws SQLException;
+        default void executionStarted(FirebirdBlob blob) throws SQLException {
+            // do nothing
+        }
 
         /**
          * Notify listener that execution of some BLOB operation had been completed.
+         * <p>
+         * The default implementation does nothing.
+         * </p>
          *
          * @param blob
          *         instance of {@link FirebirdBlob} that caused this event.
          * @throws SQLException
          *         if something went wrong.
          */
-        void executionCompleted(FirebirdBlob blob) throws SQLException;
+        default void executionCompleted(FirebirdBlob blob) throws SQLException {
+            // do nothing
+        }
+
     }
 
     /**
-     * Implementation of {@link org.firebirdsql.jdbc.FBObjectListener.BlobListener} that implements all methods as
-     * empty methods.
+     * Implementation of {@link org.firebirdsql.jdbc.FBObjectListener.BlobListener} that does nothing.
      */
-    @SuppressWarnings("java:S1186")
     public static final class NoActionBlobListener implements BlobListener {
 
         private static final BlobListener INSTANCE = new NoActionBlobListener();
@@ -236,11 +220,6 @@ public static BlobListener instance() {
         private NoActionBlobListener() {
         }
 
-        @Override
-        public void executionStarted(FirebirdBlob blob) { }
-
-        @Override
-        public void executionCompleted(FirebirdBlob blob) { }
     }
 
 }

src/main/org/firebirdsql/jdbc/FBResultSet.java

@@ -87,16 +87,6 @@ public class FBResultSet implements ResultSet, FirebirdResultSet, FBObjectListen
     private final ResultSetBehavior behavior;
     private int fetchDirection = ResultSet.FETCH_FORWARD;
 
-    @Override
-    public void allRowsFetched(FBFetcher fetcher) throws SQLException {
-        listener.allRowsFetched(this);
-    }
-
-    @Override
-    public void fetcherClosed(FBFetcher fetcher) throws SQLException {
-        // ignore, there nothing to do here
-    }
-
     @Override
     public void rowChanged(FBFetcher fetcher, RowValue newRow) throws SQLException {
         this.row = newRow;

src/main/org/firebirdsql/jdbc/FBServerScrollFetcher.java

@@ -374,7 +374,6 @@ public void close(CompletionReason completionReason) throws SQLException {
             rows.clear();
             rowsOffset = 0;
             rows = Collections.emptyList();
-            fetcherListener.fetcherClosed(this);
         }
     }
 

src/main/org/firebirdsql/jdbc/FBStatement.java

@@ -106,11 +106,11 @@ private final class RSListener implements FBObjectListener.ResultSetListener {
         private boolean rowUpdaterSeparateTransaction;
 
         /**
-         * Notify that result set was closed. This method cleans the result
-         * set reference, so that call to {@link #close()} method will not cause
-         * exception.
+         * Notify that result set was closed. This method cleans the result set reference, so that calls to
+         * {@link #close()} method will not cause an exception.
          *
-         * @param rs result set that was closed.
+         * @param rs
+         *         result set that was closed.
          */
         @Override
         public void resultSetClosed(ResultSet rs) throws SQLException {
@@ -123,26 +123,6 @@ public void resultSetClosed(ResultSet rs) throws SQLException {
             }
         }
 
-        @Override
-        public void allRowsFetched(ResultSet rs) throws SQLException {
-
-            /*
-             * According to the JDBC 3.0 specification (p.62) the result set
-             * is closed in the autocommit mode if one of the following occurs:
-             *
-             * - all of the rows have been retrieved
-             * - the associated Statement object is re-executed
-             * - another Statement object is executed on the same connection
-             */
-
-            // according to the specification we close the result set and 
-            // generate the "resultSetClosed" event, that in turn generates
-            // the "statementCompleted" event
-
-            if (connection != null && connection.getAutoCommit())
-                rs.close();
-        }
-
         @Override
         public void executionCompleted(FirebirdRowUpdater updater, boolean success) throws SQLException {
             if (rowUpdaterSeparateTransaction) {

src/main/org/firebirdsql/jdbc/FBStatementFetcher.java

@@ -126,7 +126,6 @@ public boolean next() throws SQLException {
         } else if (getNextRow() == null || (maxRows != 0 && getRowNum() == maxRows)) {
             setIsAfterLast(true);
             allRowsFetched = true;
-            fetcherListener.allRowsFetched(this);
             setRowNum(0);
             return false;
         } else {
@@ -222,7 +221,6 @@ public void close(CompletionReason completionReason) throws SQLException {
         } finally {
             stmt.removeStatementListener(rowListener);
             rows = new ArrayDeque<>(0);
-            fetcherListener.fetcherClosed(this);
         }
     }