StandaloneMybatisTransactionContext.java

/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.cfg.standalone;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.activiti.engine.impl.cfg.TransactionContext;
import org.activiti.engine.impl.cfg.TransactionListener;
import org.activiti.engine.impl.cfg.TransactionPropagation;
import org.activiti.engine.impl.cfg.TransactionState;
import org.activiti.engine.impl.db.DbSqlSession;
import org.activiti.engine.impl.interceptor.Command;
import org.activiti.engine.impl.interceptor.CommandConfig;
import org.activiti.engine.impl.interceptor.CommandContext;
import org.activiti.engine.impl.interceptor.CommandExecutor;
import org.apache.ibatis.session.SqlSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * @author Tom Baeyens
 * @author Joram Barrez
 */
public class StandaloneMybatisTransactionContext implements TransactionContext {
  
  private static Logger log = LoggerFactory.getLogger(StandaloneMybatisTransactionContext.class);

  protected CommandContext commandContext;
  protected Map<TransactionState,List<TransactionListener>> stateTransactionListeners = null;
  
  public StandaloneMybatisTransactionContext(CommandContext commandContext) {
    this.commandContext = commandContext;
  }

  public void addTransactionListener(TransactionState transactionState, TransactionListener transactionListener) {
    if (stateTransactionListeners==null) {
      stateTransactionListeners = new HashMap<TransactionState, List<TransactionListener>>();
    }
    List<TransactionListener> transactionListeners = stateTransactionListeners.get(transactionState);
    if (transactionListeners==null) {
      transactionListeners = new ArrayList<TransactionListener>();
      stateTransactionListeners.put(transactionState, transactionListeners);
    }
    transactionListeners.add(transactionListener);
  }
  
  public void commit() {
    
    log.debug("firing event committing...");
    fireTransactionEvent(TransactionState.COMMITTING, false);
    
    log.debug("committing the ibatis sql session...");
    getDbSqlSession().commit();
    log.debug("firing event committed...");
    fireTransactionEvent(TransactionState.COMMITTED, true);
    
  }

  /**
   * Fires the event for the provided {@link TransactionState}.
   * 
   * @param transactionState The {@link TransactionState} for which the listeners will be called.
   * @param executeInNewContext If true, the listeners will be called in a new command context.
   *                            This is needed for example when firing the {@link TransactionState#COMMITTED}
   *                            event: the transaction is already committed and executing logic in the same
   *                            context could lead to strange behaviour (for example doing a {@link SqlSession#update(String)}
   *                            would actually roll back the update (as the MyBatis context is already committed
   *                            and the internal flags have not been correctly set).
   */
  protected void fireTransactionEvent(TransactionState transactionState, boolean executeInNewContext) {
    if (stateTransactionListeners==null) {
      return;
    }
    final List<TransactionListener> transactionListeners = stateTransactionListeners.get(transactionState);
    if (transactionListeners==null) {
      return;
    }
    
    if (executeInNewContext) {
      CommandExecutor commandExecutor = commandContext.getProcessEngineConfiguration().getCommandExecutor(); 
      CommandConfig commandConfig = new CommandConfig(false, TransactionPropagation.REQUIRES_NEW); 
      commandExecutor.execute(commandConfig, new Command<Void>() {
        public Void execute(CommandContext commandContext) {
          executeTransactionListeners(transactionListeners, commandContext);
          return null;
        }
      });
    } else {
      executeTransactionListeners(transactionListeners, commandContext);
    }
    
  }

  protected void executeTransactionListeners(List<TransactionListener> transactionListeners, CommandContext commandContext) {
    for (TransactionListener transactionListener : transactionListeners) {
      transactionListener.execute(commandContext);
    }
  }
  
  protected DbSqlSession getDbSqlSession() {
    return commandContext.getSession(DbSqlSession.class);
  }

  public void rollback() {
    try {
      try {
        log.debug("firing event rolling back...");
        fireTransactionEvent(TransactionState.ROLLINGBACK, false);
        
      } catch (Throwable exception) {
        log.info("Exception during transaction: {}",exception.getMessage());
        commandContext.exception(exception);
      } finally {
        log.debug("rolling back ibatis sql session...");
        getDbSqlSession().rollback();
      }
      
    } catch (Throwable exception) {
      log.info("Exception during transaction: {}",exception.getMessage());
      commandContext.exception(exception);

    } finally {
      log.debug("firing event rolled back...");
      fireTransactionEvent(TransactionState.ROLLED_BACK, true);
    }
  }
}