package com.atlassian.activeobjects.internal;
   
   import com.atlassian.sal.api.transaction.TransactionCallback;
   import net.java.ao.ActiveObjectsException;
   import net.java.ao.EntityManager;
   import net.java.ao.Transaction;
   
   import java.sql.SQLException;
   
  import static com.google.common.base.Preconditions.checkNotNull;
  
  /**
   * Implementation of the {@link com.atlassian.activeobjects.internal.TransactionManager} that
   * relies on Active Objects transaction mechanism.
   */
  final class EntityManagedTransactionManager extends AbstractLoggingTransactionManager {
      private final EntityManager entityManager;
  
      EntityManagedTransactionManager(EntityManager entityManager) {
          this.entityManager = checkNotNull(entityManager);
      }
  
      <T> T inTransaction(final TransactionCallback<T> callback) {
          try {
              return new Transaction<T>(entityManager) {
                  public T run() {
                      return callback.doInTransaction();
                  }
              }.execute();
          } catch (SQLException e) {
              throw new ActiveObjectsException(e);
          }
      }
  }