Support Statement.closeOnCompletion.

Check a statement after a dependent result set is closed.

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

Closes: #180

Author: nicktorwald

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);
         }
 

src/main/java/org/tarantool/jdbc/SQLResultSet.java

@@ -38,12 +38,12 @@
 
 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 final Statement statement;
+    private final TarantoolStatement statement;
     private final int maxRows;
 
     private AtomicBoolean isClosed = new AtomicBoolean(false);
@@ -52,7 +52,7 @@ 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();
@@ -89,7 +89,13 @@ public List<Object> getCurrentRow() 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();
+            }
         }
     }
 
@@ -370,11 +376,13 @@ 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);
     }
 
@@ -1099,7 +1107,7 @@ 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

src/main/java/org/tarantool/jdbc/SQLStatement.java

@@ -22,7 +22,7 @@
  * 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;
 
@@ -32,6 +32,8 @@ 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;
@@ -313,21 +315,33 @@ public boolean isPoolable() throws SQLException {
 
     @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) {
+            return;
+        }
+        if (resultSet != null && !resultSet.isClosed()) {
+            return;
+        }
+        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
@@ -376,16 +390,7 @@ 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);

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;
+
+}

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

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));
     }
@@ -246,4 +248,35 @@ 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());
+    }
+
 }