MONDRIAN: Fix MONDRIAN-738, "Statements not being closed". Now Statem…

…ents are

    closed explicitly, after ResultSets and before Connections.

[git-p4: depot-paths = "//open/mondrian-release/3.2/": change = 13617]

src/main/mondrian/rolap/SqlStatement.java

@@ -216,15 +216,29 @@ public void close() {
             haveSemaphore = false;
             querySemaphore.leave();
         }
+
+        // According to the JDBC spec, closing a statement automatically closes
+        // its result sets, and closing a connection automatically closes its
+        // statements. But let's be conservative and close everything
+        // explicitly.
+        Statement statement = null;
         if (resultSet != null) {
             try {
+                statement = resultSet.getStatement();
                 resultSet.close();
             } catch (SQLException e) {
                 throw Util.newError(message + "; sql=[" + sql + "]");
             } finally {
                 resultSet = null;
             }
         }
+        if (statement != null) {
+            try {
+                statement.close();
+            } catch (SQLException e) {
+                throw Util.newError(message + "; sql=[" + sql + "]");
+            }
+        }
         if (jdbcConnection != null) {
             try {
                 jdbcConnection.close();

src/main/mondrian/spi/impl/MySqlDialect.java

@@ -9,11 +9,8 @@
 package mondrian.spi.impl;
 
 import mondrian.olap.Util;
-import mondrian.olap.MondrianDef;
-import mondrian.util.Pair;
 
 import java.util.List;
-import java.util.Iterator;
 import java.util.Map;
 import java.sql.*;
 
@@ -48,6 +45,8 @@ protected boolean acceptsConnection(Connection connection) {
      * Creates a MySqlDialect.
      *
      * @param connection Connection
+     *
+     * @throws SQLException on error
      */
     public MySqlDialect(Connection connection) throws SQLException {
         super(connection);
@@ -136,21 +135,31 @@ protected boolean deduceSupportsSelectNotInGroupBy(Connection connection)
     private String getCurrentSqlMode(Connection connection)
         throws SQLException
     {
-        return getSqlMode(connection, true);
+        return getSqlMode(connection, Scope.SESSION);
     }
 
-    private String getSqlMode(Connection connection, boolean session)
+    private String getSqlMode(Connection connection, Scope scope)
         throws SQLException
     {
-        String scope = session ? "SESSION" : "GLOBAL";
         String sqlmode = null;
-        Statement s = connection.createStatement();
-        if (s.execute("SELECT @@" + scope + ".sql_mode")) {
-            ResultSet rs = s.getResultSet();
-            rs.next();
-            sqlmode = rs.getString(1);
+        Statement s = null;
+        try {
+            s = connection.createStatement();
+            if (s.execute("SELECT @@" + scope + ".sql_mode")) {
+                ResultSet rs = s.getResultSet();
+                if (rs.next()) {
+                    sqlmode = rs.getString(1);
+                }
+            }
+        } finally {
+            if (s != null) {
+                try {
+                    s.close();
+                } catch (SQLException e) {
+                    // ignore
+                }
+            }
         }
-        s.close();
         return sqlmode;
     }
 
@@ -215,6 +224,11 @@ public boolean requiresOrderByAlias() {
     public boolean supportsMultiValueInExpr() {
         return true;
     }
+
+    private enum Scope {
+        SESSION,
+        GLOBAL
+    }
 }
 
 // End MySqlDialect.java