Package org.apache.tomcat.dbcp.dbcp2.managed

Class LocalXAConnectionFactory.LocalXAResource

java.lang.Object
org.apache.tomcat.dbcp.dbcp2.managed.LocalXAConnectionFactory.LocalXAResource
All Implemented Interfaces:
XAResource
Enclosing class:
LocalXAConnectionFactory
protected static class LocalXAConnectionFactory.LocalXAResource extends Object implements XAResource
LocalXAResource is a fake XAResource for non-XA connections. When a transaction is started the connection auto-commit is turned off. When the connection is committed or rolled back, the commit or rollback method is called on the connection and then the original auto-commit value is restored.

The LocalXAResource also respects the connection read-only setting. If the connection is read-only the commit method will not be called, and the prepare method returns the XA_RDONLY.

It is assumed that the wrapper around a managed connection disables the setAutoCommit(), commit(), rollback() and setReadOnly() methods while a transaction is in progress.

Since:
2.0

  • Constructor Details

    • LocalXAResource

      public LocalXAResource(Connection localTransaction)
      Constructs a new instance for a given connection.
      Parameters:
      localTransaction - A connection.

  • Method Details

    • commit

      public void commit(Xid xid, boolean flag) throws XAException
      Commits the transaction and restores the original auto commit setting.
      Specified by:
      commit in interface XAResource
      Parameters:
      xid - the id of the transaction branch for this connection
      flag - ignored
      Throws:
      XAException - if connection.commit() throws an SQLException

    • end

      public void end(Xid xid, int flag) throws XAException
      This method does nothing.
      Specified by:
      end in interface XAResource
      Parameters:
      xid - the id of the transaction branch for this connection
      flag - ignored
      Throws:
      XAException - if the connection is already enlisted in another transaction

    • forget

      public void forget(Xid xid)
      Clears the currently associated transaction if it is the specified xid.
      Specified by:
      forget in interface XAResource
      Parameters:
      xid - the id of the transaction to forget

    • getTransactionTimeout

      public int getTransactionTimeout()
      Always returns 0 since we have no way to set a transaction timeout on a JDBC connection.
      Specified by:
      getTransactionTimeout in interface XAResource
      Returns:
      always 0

    • getXid

      public Xid getXid()
      Gets the current xid of the transaction branch associated with this XAResource.
      Returns:
      the current xid of the transaction branch associated with this XAResource.

    • isSameRM

      public boolean isSameRM(XAResource xaResource)
      Returns true if the specified XAResource == this XAResource.
      Specified by:
      isSameRM in interface XAResource
      Parameters:
      xaResource - the XAResource to test
      Returns:
      true if the specified XAResource == this XAResource; false otherwise

    • prepare

      public int prepare(Xid xid)
      This method does nothing since the LocalXAConnection does not support two-phase-commit. This method will return XAResource.XA_RDONLY if the connection isReadOnly(). This assumes that the physical connection is wrapped with a proxy that prevents an application from changing the read-only flag while enrolled in a transaction.
      Specified by:
      prepare in interface XAResource
      Parameters:
      xid - the id of the transaction branch for this connection
      Returns:
      XAResource.XA_RDONLY if the connection.isReadOnly(); XAResource.XA_OK otherwise

    • recover

      public Xid[] recover(int flag)
      Always returns a zero length Xid array. The LocalXAConnectionFactory cannot support recovery, so no xids will ever be found.
      Specified by:
      recover in interface XAResource
      Parameters:
      flag - ignored since recovery is not supported
      Returns:
      always a zero length Xid array.

    • rollback

      public void rollback(Xid xid) throws XAException
      Rolls back the transaction and restores the original auto commit setting.
      Specified by:
      rollback in interface XAResource
      Parameters:
      xid - the id of the transaction branch for this connection
      Throws:
      XAException - if connection.rollback() throws an SQLException

    • setTransactionTimeout

      public boolean setTransactionTimeout(int transactionTimeout)
      Always returns false since we have no way to set a transaction timeout on a JDBC connection.
      Specified by:
      setTransactionTimeout in interface XAResource
      Parameters:
      transactionTimeout - ignored since we have no way to set a transaction timeout on a JDBC connection
      Returns:
      always false

    • start

      public void start(Xid xid, int flag) throws XAException
      Signals that a connection has been enrolled in a transaction. This method saves off the current auto commit flag, and then disables auto commit. The original auto commit setting is restored when the transaction completes.
      Specified by:
      start in interface XAResource
      Parameters:
      xid - the id of the transaction branch for this connection
      flag - either XAResource.TMNOFLAGS or XAResource.TMRESUME
      Throws:
      XAException - if the connection is already enlisted in another transaction, or if auto-commit could not be disabled