Support Statement.closeOnCompletion.

Check a statement after all its dependent result set are closed.

Extract TarantoolStatement as tarantool specific extension interface to
be used for internal purposes (incompatible vendor API).

Closes: #180

Author: nicktorwald

Diff for: src/main/java/org/tarantool/jdbc/SQLDatabaseMetadata.java

@@ -1126,8 +1126,8 @@ private SQLNullResultSet sqlNullResultSet(List<String> columnNames, List<List<Ob
         return new SQLNullResultSet(SQLResultHolder.ofQuery(meta, rows), createMetadataStatement());
     }
 
-    private SQLStatement createMetadataStatement() throws SQLException {
-        return connection.createStatement().unwrap(SQLStatement.class);
+    private TarantoolStatement createMetadataStatement() throws SQLException {
+        return connection.createStatement().unwrap(TarantoolStatement.class);
     }
 
     private static <T> T ensureType(Class<T> cls, Object v) throws Exception {
@@ -1152,7 +1152,7 @@ private SQLNullResultSet emptyResultSet(List<String> colNames) throws SQLExcepti
 
     protected class SQLNullResultSet extends SQLResultSet {
 
-        public SQLNullResultSet(SQLResultHolder holder, SQLStatement ownerStatement) throws SQLException {
+        public SQLNullResultSet(SQLResultHolder holder, TarantoolStatement ownerStatement) throws SQLException {
             super(holder, ownerStatement);
         }
 

Diff for: src/main/java/org/tarantool/jdbc/SQLResultSet.java

@@ -38,13 +38,13 @@
 
 public class SQLResultSet implements ResultSet {
 
-    private final CursorIterator<List<Object>> iterator;
-    private final SQLResultSetMetaData metaData;
+    private CursorIterator<List<Object>> iterator;
+    private SQLResultSetMetaData metaData;
 
     private Map<String, Integer> columnByNameLookups;
     private boolean lastColumnWasNull;
 
-    private final Statement statement;
+    private final TarantoolStatement statement;
     private final int maxRows;
 
     private AtomicBoolean isClosed = new AtomicBoolean(false);
@@ -53,7 +53,7 @@ public class SQLResultSet implements ResultSet {
     private final int concurrencyLevel;
     private final int holdability;
 
-    public SQLResultSet(SQLResultHolder holder, SQLStatement ownerStatement) throws SQLException {
+    public SQLResultSet(SQLResultHolder holder, TarantoolStatement ownerStatement) throws SQLException {
         metaData = new SQLResultSetMetaData(holder.getSqlMetadata());
         statement = ownerStatement;
         scrollType = statement.getResultSetType();
@@ -108,7 +108,13 @@ protected Number getNullableNumber(int columnIndex) throws SQLException {
     @Override
     public void close() throws SQLException {
         if (isClosed.compareAndSet(false, true)) {
-            iterator.close();
+            try {
+                iterator.close();
+                iterator = null;
+                metaData = null;
+            } finally {
+                statement.checkCompletion();
+            }
         }
     }
 
@@ -393,11 +399,13 @@ public String getCursorName() throws SQLException {
 
     @Override
     public ResultSetMetaData getMetaData() throws SQLException {
+        checkNotClosed();
         return metaData;
     }
 
     @Override
     public int findColumn(String columnLabel) throws SQLException {
+        checkNotClosed();
         return findColumnIndex(columnLabel);
     }
 
@@ -1122,7 +1130,7 @@ public <T> T unwrap(Class<T> type) throws SQLException {
         if (isWrapperFor(type)) {
             return type.cast(this);
         }
-        throw new SQLNonTransientException("ResultSet does not wrap " + type.getName());
+        throw new SQLNonTransientException("SQLResultSet does not wrap " + type.getName());
     }
 
     @Override

Diff for: src/main/java/org/tarantool/jdbc/SQLStatement.java

@@ -21,7 +21,7 @@
  * types of cursors.
  * Supports only {@link ResultSet#HOLD_CURSORS_OVER_COMMIT} holdability type.
  */
-public class SQLStatement implements Statement {
+public class SQLStatement implements TarantoolStatement {
 
     protected final SQLConnection connection;
 
@@ -31,6 +31,8 @@ public class SQLStatement implements Statement {
     protected SQLResultSet resultSet;
     protected int updateCount;
 
+    private boolean isCloseOnCompletion;
+
     private final int resultSetType;
     private final int resultSetConcurrency;
     private final int resultSetHoldability;
@@ -310,23 +312,44 @@ public boolean isPoolable() throws SQLException {
         throw new SQLFeatureNotSupportedException();
     }
 
+    /**
+     * {@inheritDoc}
+     * <p>
+     * <strong>Impl Note:</strong> this method doesn't affect
+     * execution methods which close the last result set implicitly.
+     * It is applied only when {@link ResultSet#close()} is invoked
+     * explicitly by the app.
+     *
+     * @throws SQLException if this method is called on a closed
+     * {@code Statement}
+     */
     @Override
     public void closeOnCompletion() throws SQLException {
-
+        checkNotClosed();
+        isCloseOnCompletion = true;
     }
 
     @Override
     public boolean isCloseOnCompletion() throws SQLException {
         checkNotClosed();
-        return false;
+        return isCloseOnCompletion;
+    }
+
+    @Override
+    public void checkCompletion() throws SQLException {
+        if (isCloseOnCompletion &&
+            resultSet != null &&
+            resultSet.isClosed()) {
+            close();
+        }
     }
 
     @Override
     public <T> T unwrap(Class<T> type) throws SQLException {
         if (isWrapperFor(type)) {
             return type.cast(this);
         }
-        throw new SQLNonTransientException("Statement does not wrap " + type.getName());
+        throw new SQLNonTransientException("SQLStatement does not wrap " + type.getName());
     }
 
     @Override
@@ -338,15 +361,18 @@ public boolean isWrapperFor(Class<?> type) throws SQLException {
      * Clears the results of the most recent execution.
      */
     protected void discardLastResults() throws SQLException {
+        final SQLResultSet lastResultSet = resultSet;
+
         clearWarnings();
         updateCount = -1;
-        if (resultSet != null) {
+        resultSet = null;
+
+        if (lastResultSet != null) {
             try {
-                resultSet.close();
+                lastResultSet.close();
             } catch (Exception ignored) {
                 // No-op.
             }
-            resultSet = null;
         }
     }
 
@@ -375,16 +401,7 @@ protected boolean executeInternal(String sql, Object... params) throws SQLExcept
         return holder.isQueryResult();
     }
 
-    /**
-     * Returns {@link ResultSet} which will be initialized by <code>data</code>.
-     *
-     * @param data predefined result to be wrapped by {@link ResultSet}
-     *
-     * @return wrapped result
-     *
-     * @throws SQLException if a database access error occurs or
-     *                      this method is called on a closed <code>Statement</code>
-     */
+    @Override
     public ResultSet executeMetadata(SQLResultHolder data) throws SQLException {
         checkNotClosed();
         return createResultSet(data);

Diff for: src/main/java/org/tarantool/jdbc/TarantoolStatement.java

@@ -0,0 +1,30 @@
+package org.tarantool.jdbc;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+/**
+ * Tarantool specific statement extensions.
+ */
+public interface TarantoolStatement extends Statement {
+
+    /**
+     * Checks for statement completion and closes itself,
+     * according to {@link Statement#closeOnCompletion()}.
+     */
+    void checkCompletion() throws SQLException;
+
+    /**
+     * Returns {@link ResultSet} which will be initialized by <code>data</code>.
+     *
+     * @param data predefined result to be wrapped by {@link ResultSet}
+     *
+     * @return wrapped result
+     *
+     * @throws SQLException if a database access error occurs or
+     *                      this method is called on a closed <code>Statement</code>
+     */
+    ResultSet executeMetadata(SQLResultHolder data) throws SQLException;
+
+}

Diff for: src/test/java/org/tarantool/jdbc/JdbcResultSetIT.java

@@ -167,8 +167,12 @@ public void testResultSetMetadataAfterClose() throws SQLException {
         assertNotNull(resultSet);
         ResultSetMetaData metaData = resultSet.getMetaData();
         assertNotNull(metaData);
+
+        int expectedColumnSize = 2;
+        assertEquals(expectedColumnSize, metaData.getColumnCount());
+
         resultSet.close();
-        assertEquals(metaData, resultSet.getMetaData());
+        assertEquals(expectedColumnSize, metaData.getColumnCount());
     }
 
     @Test

Diff for: src/test/java/org/tarantool/jdbc/JdbcStatementIT.java

@@ -157,12 +157,14 @@ public void execute() throws Throwable {
 
     @Test
     public void testUnwrap() throws SQLException {
+        assertEquals(stmt, stmt.unwrap(TarantoolStatement.class));
         assertEquals(stmt, stmt.unwrap(SQLStatement.class));
         assertThrows(SQLException.class, () -> stmt.unwrap(Integer.class));
     }
 
     @Test
     public void testIsWrapperFor() throws SQLException {
+        assertTrue(stmt.isWrapperFor(TarantoolStatement.class));
         assertTrue(stmt.isWrapperFor(SQLStatement.class));
         assertFalse(stmt.isWrapperFor(Integer.class));
     }
@@ -247,4 +249,103 @@ void testStatementConnection() throws SQLException {
         Statement statement = conn.createStatement();
         assertEquals(conn, statement.getConnection());
     }
+
+    @Test
+    void testCloseOnCompletion() throws SQLException {
+        assertFalse(stmt.isCloseOnCompletion());
+        stmt.closeOnCompletion();
+        assertTrue(stmt.isCloseOnCompletion());
+    }
+
+    @Test
+    void testCloseOnCompletionDisabled() throws SQLException {
+        ResultSet resultSet = stmt.executeQuery("SELECT val FROM test WHERE id=1");
+        assertFalse(stmt.isClosed());
+        assertFalse(resultSet.isClosed());
+
+        resultSet.close();
+        assertTrue(resultSet.isClosed());
+        assertFalse(stmt.isClosed());
+    }
+
+    @Test
+    void testCloseOnCompletionEnabled() throws SQLException {
+        stmt.closeOnCompletion();
+        ResultSet resultSet = stmt.executeQuery("SELECT val FROM test WHERE id=1");
+
+        assertFalse(stmt.isClosed());
+        assertFalse(resultSet.isClosed());
+
+        resultSet.close();
+        assertTrue(resultSet.isClosed());
+        assertTrue(stmt.isClosed());
+    }
+
+    @Test
+    void testCloseOnCompletionAfterResultSet() throws SQLException {
+        ResultSet resultSet = stmt.executeQuery("SELECT val FROM test WHERE id=1");
+        stmt.closeOnCompletion();
+
+        assertFalse(stmt.isClosed());
+        assertFalse(resultSet.isClosed());
+
+        resultSet.close();
+        assertTrue(resultSet.isClosed());
+        assertTrue(stmt.isClosed());
+    }
+
+    @Test
+    void testCloseOnCompletionMultipleResultSets() throws SQLException {
+        stmt.closeOnCompletion();
+        ResultSet resultSet = stmt.executeQuery("SELECT val FROM test WHERE id=1");
+        ResultSet anotherResultSet = stmt.executeQuery("SELECT val FROM test WHERE id=2");
+
+        assertTrue(resultSet.isClosed());
+        assertFalse(anotherResultSet.isClosed());
+        assertFalse(stmt.isClosed());
+
+        anotherResultSet.close();
+        assertTrue(anotherResultSet.isClosed());
+        assertTrue(stmt.isClosed());
+    }
+
+    @Test
+    void testCloseOnCompletionUpdateQueries() throws SQLException {
+        stmt.closeOnCompletion();
+
+        int updateCount = stmt.executeUpdate("INSERT INTO test(id, val) VALUES (5, 'five')");
+        assertEquals(1, updateCount);
+        assertFalse(stmt.isClosed());
+
+        updateCount = stmt.executeUpdate("INSERT INTO test(id, val) VALUES (6, 'six')");
+        assertEquals(1, updateCount);
+        assertFalse(stmt.isClosed());
+    }
+
+    @Test
+    void testCloseOnCompletionMixedQueries() throws SQLException {
+        stmt.closeOnCompletion();
+
+        int updateCount = stmt.executeUpdate("INSERT INTO test(id, val) VALUES (7, 'seven')");
+        assertEquals(1, updateCount);
+        assertFalse(stmt.isClosed());
+
+        ResultSet resultSet = stmt.executeQuery("SELECT val FROM test WHERE id=7");
+        assertFalse(resultSet.isClosed());
+        assertFalse(stmt.isClosed());
+
+        updateCount = stmt.executeUpdate("INSERT INTO test(id, val) VALUES (8, 'eight')");
+        assertEquals(1, updateCount);
+        assertTrue(resultSet.isClosed());
+        assertFalse(stmt.isClosed());
+
+        resultSet = stmt.executeQuery("SELECT val FROM test WHERE id=8");
+        assertFalse(resultSet.isClosed());
+        assertFalse(stmt.isClosed());
+
+        resultSet.close();
+        assertTrue(resultSet.isClosed());
+        assertTrue(stmt.isClosed());
+    }
+
 }