Fix for http://code.google.com/p/mybatis/issues/detail?id=197 and hopefully http://code.google.com/p/mybatis/issues/detail?id=147 . Ignore resetAutocommit exceptions and refactored exception handling on close.

Author: emacarron

src/main/java/org/apache/ibatis/executor/BaseExecutor.java

@@ -1,24 +1,36 @@
 package org.apache.ibatis.executor;
 
-import org.apache.ibatis.cache.CacheKey;
-import org.apache.ibatis.cache.impl.PerpetualCache;
 import static org.apache.ibatis.executor.ExecutionPlaceholder.EXECUTION_PLACEHOLDER;
 
-import org.apache.ibatis.mapping.*;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+import org.apache.ibatis.cache.CacheKey;
+import org.apache.ibatis.cache.impl.PerpetualCache;
+import org.apache.ibatis.logging.Log;
+import org.apache.ibatis.logging.LogFactory;
+import org.apache.ibatis.mapping.BoundSql;
+import org.apache.ibatis.mapping.MappedStatement;
+import org.apache.ibatis.mapping.ParameterMapping;
+import org.apache.ibatis.mapping.ParameterMode;
+import org.apache.ibatis.mapping.StatementType;
 import org.apache.ibatis.reflection.MetaObject;
+import org.apache.ibatis.session.Configuration;
 import org.apache.ibatis.session.ResultHandler;
 import org.apache.ibatis.session.RowBounds;
-import org.apache.ibatis.session.Configuration;
 import org.apache.ibatis.transaction.Transaction;
 import org.apache.ibatis.type.TypeHandlerRegistry;
 
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.*;
-import java.util.concurrent.ConcurrentLinkedQueue;
-
 public abstract class BaseExecutor implements Executor {
 
+  private static final Log log = LogFactory.getLog(BaseExecutor.class);
+
   protected Transaction transaction;
 
   protected ConcurrentLinkedQueue<DeferredLoad> deferredLoads;
@@ -54,6 +66,7 @@ public void close(boolean forceRollback) {
       }
     } catch (SQLException e) {
       // Ignore.  There's nothing that can be done at this point.
+      log.debug("Unexpected exception on closing transaction.  Cause: " + e);
     } finally {
       transaction = null;
       deferredLoads = null;
@@ -262,8 +275,6 @@ public void load() {
       }
       resultObject.setValue(property, value);
     }
-
   }
 
-
 }

src/main/java/org/apache/ibatis/session/defaults/DefaultSqlSession.java

@@ -165,8 +165,6 @@ public void close() {
     try {
       executor.close(isCommitOrRollbackRequired(false));
       dirty = false;
-    } catch (Exception e) {
-      throw ExceptionFactory.wrapException("Error closing transaction.  Cause: " + e, e);
     } finally {
       ErrorContext.instance().reset();
     }

src/main/java/org/apache/ibatis/transaction/jdbc/JdbcTransaction.java

@@ -1,13 +1,17 @@
 package org.apache.ibatis.transaction.jdbc;
 
-import org.apache.ibatis.transaction.Transaction;
-import org.apache.ibatis.transaction.TransactionException;
-
 import java.sql.Connection;
 import java.sql.SQLException;
 
+import org.apache.ibatis.logging.Log;
+import org.apache.ibatis.logging.LogFactory;
+import org.apache.ibatis.transaction.Transaction;
+import org.apache.ibatis.transaction.TransactionException;
+
 public class JdbcTransaction implements Transaction {
 
+  private static final Log log = LogFactory.getLog(JdbcTransaction.class);
+
   protected Connection connection;
 
   public JdbcTransaction(Connection connection, boolean desiredAutoCommit) {
@@ -53,14 +57,15 @@ protected void setDesiredAutoCommit(boolean desiredAutoCommit) {
   protected void resetAutoCommit() {
     try {
       if (!connection.getAutoCommit()) {
-        // for compatibility we always use true, as some drivers don't like being left in "false" mode.
+        // MyBatis does not call commit/rollback on a connection if just selects were performed.
+        // Some databases start transactions with select statements 
+        // and they mandate a commit/rollback before closing the connection. 
+        // A workaround is setting the autocommit to true before closing the connection.
         connection.setAutoCommit(true);
       }
     } catch (SQLException e) {
-      // Only a very poorly implemented driver would fail here,
-      // and there's not much we can do about that.
-      throw new TransactionException("Error configuring AutoCommit.  " +
-          "Your driver may not support getAutoCommit() or setAutoCommit(). Cause: " + e, e);
+      log.debug("Error resetting autocommit to true " +
+          "before closing the connection.  Cause: " + e);
     }
   }
 

src/main/java/org/apache/ibatis/transaction/managed/ManagedTransaction.java

@@ -1,17 +1,14 @@
 package org.apache.ibatis.transaction.managed;
 
-import org.apache.ibatis.logging.Log;
-import org.apache.ibatis.logging.LogFactory;
-import org.apache.ibatis.transaction.Transaction;
-
 import java.sql.Connection;
 import java.sql.SQLException;
 
-public class ManagedTransaction implements Transaction {
+import org.apache.ibatis.transaction.Transaction;
 
-  private static final Log log = LogFactory.getLog(ManagedTransaction.class);
+public class ManagedTransaction implements Transaction {
 
   private Connection connection;
+  
   private boolean closeConnection;
 
   public ManagedTransaction(Connection connection, boolean closeConnection) {
@@ -33,12 +30,7 @@ public void rollback() throws SQLException {
 
   public void close() throws SQLException {
     if (closeConnection) {
-      try {
-        if (connection != null) connection.close();
-      } catch (SQLException e) {
-        // Log and ignore.  Nothing more that should be done here.
-        log.error(e.getMessage(), e);
-      }
+      connection.close();
     }
   }