[jOOQ/jOOQ#3419] Improved BatchedConnection

- Added DEBUG logging
- Fixed close() and execute() semantics in some cases

jOOQ/src/main/java/org/jooq/tools/jdbc/BatchedConnection.java

@@ -79,8 +79,8 @@ import java.util.regex.Pattern;
  */
 public class BatchedConnection extends DefaultConnection {
 
-    private String            lastSQL;
-    private PreparedStatement lastStatement;
+    String            lastSQL;
+    PreparedStatement lastStatement;
 
     public BatchedConnection(Connection delegate) {
         super(delegate);
@@ -90,17 +90,20 @@ public class BatchedConnection extends DefaultConnection {
     // XXX: Utilities
     // -------------------------------------------------------------------------
 
-    private void checkBatch(String sql) throws SQLException {
+    private void executeLastBatch(String sql) throws SQLException {
         if (!sql.equals(lastSQL))
             executeLastBatch();
     }
 
     private void executeLastBatch() throws SQLException {
         if (lastStatement != null) {
-            lastStatement.executeBatch();
+            if (lastStatement instanceof BatchedPreparedStatement && ((BatchedPreparedStatement) lastStatement).batches > 0)
+                lastStatement.executeBatch();
+
             safeClose(lastStatement);
-            clearLastBatch();
         }
+
+        clearLastBatch();
     }
 
     void clearLastBatch() {
@@ -184,16 +187,16 @@ public class BatchedConnection extends DefaultConnection {
 
     @Override
     public PreparedStatement prepareStatement(String sql) throws SQLException {
-        checkBatch(sql);
+        executeLastBatch(sql);
         return lastStatement != null ? lastStatement : (lastStatement = prepareStatement0(lastSQL = sql));
     }
 
+    // TODO: Can we implement this in a more sophisticated way without invoking the costly parser?
     static final Pattern P_DML = Pattern.compile("\\s*(?i:delete|insert|merge|update).*");
 
     private PreparedStatement prepareStatement0(String sql) throws SQLException {
-
-        // TODO: More sophistication here
         PreparedStatement result = super.prepareStatement(sql);
+
         return P_DML.matcher(sql).matches()
              ? new BatchedPreparedStatement(this, result)
              : result;

jOOQ/src/main/java/org/jooq/tools/jdbc/BatchedPreparedStatement.java

@@ -41,6 +41,8 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 
+import org.jooq.tools.JooqLogger;
+
 /**
  * A batched statement.
  * <p>
@@ -53,15 +55,32 @@ import java.sql.SQLException;
  */
 public class BatchedPreparedStatement extends DefaultPreparedStatement {
 
-    private int batches;
+    private static final JooqLogger log = JooqLogger.getLogger(BatchedPreparedStatement.class);
+    int                             batches;
 
     public BatchedPreparedStatement(BatchedConnection connection, PreparedStatement delegate) {
         super(delegate, connection);
     }
 
-    // -------------------------------------------------------------------------
-    // XXX: Utilities
-    // -------------------------------------------------------------------------
+    public BatchedConnection getBatchedConnection() throws SQLException {
+        return (BatchedConnection) super.getConnection();
+    }
+
+    private void resetBatches() {
+        batches = 0;
+    }
+
+    private void logBatch() throws SQLException {
+        if (log.isDebugEnabled())
+            log.debug("BatchedStatement", "Batched " + batches + " times: " + getBatchedConnection().lastSQL);
+    }
+
+    private void logExecution() throws SQLException {
+        if (log.isDebugEnabled())
+            log.debug("BatchedStatement", "Executed " + batches + " batches: " + getBatchedConnection().lastSQL);
+
+        resetBatches();
+    }
 
     // -------------------------------------------------------------------------
     // XXX: Executing queries
@@ -108,21 +127,18 @@ public class BatchedPreparedStatement extends DefaultPreparedStatement {
     @Override
     public void addBatch() throws SQLException {
         batches++;
+        logBatch();
         super.addBatch();
     }
 
-    @Override
-    public void addBatch(String sql) throws SQLException {
-        super.addBatch(sql);
-    }
-
     @Override
     public void clearBatch() throws SQLException {
-        super.clearBatch();
+        throw new UnsupportedOperationException("Clearing a batch is not yet supported");
     }
 
     @Override
     public int[] executeBatch() throws SQLException {
+        logExecution();
         return super.executeBatch();
     }
 
@@ -130,6 +146,7 @@ public class BatchedPreparedStatement extends DefaultPreparedStatement {
 
     @Override
     public long[] executeLargeBatch() throws SQLException {
+        logExecution();
         return super.executeLargeBatch();
     }
 
@@ -139,6 +156,11 @@ public class BatchedPreparedStatement extends DefaultPreparedStatement {
     // XXX: Unsupported static statement execution features
     // -------------------------------------------------------------------------
 
+    @Override
+    public void addBatch(String sql) throws SQLException {
+        throw new UnsupportedOperationException("No static statement methods can be called");
+    }
+
     @Override
     public boolean execute(String sql) throws SQLException {
         throw new UnsupportedOperationException("No static statement methods can be called");
@@ -214,10 +236,10 @@ public class BatchedPreparedStatement extends DefaultPreparedStatement {
 
     @Override
     public ResultSet executeQuery() throws SQLException {
-        if (batches > 0)
-            throw new UnsupportedOperationException("Cannot batch result queries");
-        else
+        if (batches == 0)
             return super.executeQuery();
+        else
+            throw new UnsupportedOperationException("Cannot batch result queries");
     }
 
     @Override