Package org.apache.cayenne.tx

Class ReadOnlyTransaction

java.lang.Object
org.apache.cayenne.tx.ReadOnlyTransaction
All Implemented Interfaces:
Transaction
public class ReadOnlyTransaction extends Object implements Transaction
A minimal Transaction for read-only (selecting) queries that run outside a managed transaction. It is not a real transaction - it exists only so that a DataNode has a thread-bound transaction to acquire and release its connection through, and it keeps that connection in autocommit mode (each select commits on its own, which is optimal for reads). It never commits or rolls back, and fires no TransactionListener events.

Reads that require a real transaction (e.g. materializing PostgreSQL oid/BLOB large objects) are not routed here - they use a CayenneTransaction.

Since:
5.0

  • Constructor Details

    • ReadOnlyTransaction

      public ReadOnlyTransaction()

  • Method Details

    • getOrCreateConnection

      public Connection getOrCreateConnection(String connectionName, DataSource dataSource) throws SQLException
      Description copied from interface: Transaction
      Retrieves a connection for the given symbolic name. If it does not exists, creates a new connection using provided DataSource, and registers it internally.
      Specified by:
      getOrCreateConnection in interface Transaction
      Parameters:
      connectionName - a symbolic name of the connection. Cayenne DataNodes generate a name in the form of "DataNode.Connection.nodename".
      dataSource - DataSource that provides new connections.
      Returns:
      a connection that participates in the current transaction.
      Throws:
      SQLException

    • commit

      public void commit()
      Specified by:
      commit in interface Transaction

    • rollback

      public void rollback()
      Specified by:
      rollback in interface Transaction

    • getConnections

      public Map<String,Connection> getConnections()
      Description copied from interface: Transaction
      Returns all connections associated with the transaction.
      Specified by:
      getConnections in interface Transaction
      Returns:
      connections associated with the transaction.

    • begin

      public void begin()
      Description copied from interface: Transaction
      Starts a Transaction. If Transaction is not started explicitly, it will be started when the first connection is added.
      Specified by:
      begin in interface Transaction

    • setRollbackOnly

      public void setRollbackOnly()
      Specified by:
      setRollbackOnly in interface Transaction

    • isRollbackOnly

      public boolean isRollbackOnly()
      Specified by:
      isRollbackOnly in interface Transaction

    • addListener

      public void addListener(TransactionListener listener)
      Specified by:
      addListener in interface Transaction

    • isExternal

      public boolean isExternal()
      Description copied from interface: Transaction
      Is this transaction managed by external transaction manager
      Specified by:
      isExternal in interface Transaction