 | Mailing List | | Home | | Forum Home | | JBoss - Java Application Server | | Struts - A MVC web framework | | Tomcat - JSP/Servlet container | | iText - An open source PDF Java Library | | JDOM - JDOM XML Parser | | J2EE - A mailing list for Java(tm) 2 Platform, Enterprise Edition | | J2EE Pattern - An interest list for Sun Java Center J2EE Pattern Catalog | | Servlet - A mailing list for discussion about Sun Microsystem's Java Servlet API Technology | | JSP - A mailing list about Java Server Pages specification and reference | |
Struts & Hibernate
|
|
|
| | | Transactions | Transactions 2004-05-25 - By Jaise George
Back
The following is an excerpt from the URL
<http://info.borland.com/techpubs/jbuilder/jbuilder8/enterprise/transact
ions.html>
http://info.borland.com/techpubs/jbuilder/jbuilder8/enterprise/transacti
ons.html
Local and global transactions
When a single connection to a database exists, the enterprise bean can
directly control the transaction by calling commit() or rollback() on
the connection. This type of transaction is a local transaction. Using
global transactions, all database connections are registered with the
global transaction service, which handles the transaction. For a global
transaction, the enterprise bean never makes calls directly on a
database connection itself.
A bean that uses bean-managed transaction demarcation uses the
javax.transaction.UserTransaction  interface to identify the boundaries
of a global transaction. When a bean uses container-managed demarcation,
the container interrupts each client call to control the transaction
demarcation, using the transaction attribute set in the bean's
deployment descriptor by the application assembler. The transaction
attribute also determines whether the transaction is local or global.
For container-managed transactions, the container follows certain rules
to determine when it should do a local versus a global transaction.
Usually a container calls the method within a local transaction after
verifying that no global transaction already exists. It also verifies
that it isn't expected to start a new global transaction and that the
transaction attributes are set for container-managed transactions. The
container automatically wraps a method call within a local transaction
if one of the follow conditions is true:
The transaction attribute is set to NotSupported and the container
detects that the database resources were accessed.
The transaction attribute is set to Supports and the container detects
that the method wasn't invoked from within a global transaction.
The transaction attribute is set to Never and the container detects that
database resources are accessed.
Best Regards
Jaise
-- --Original Message-- --
From: A mailing list for Java(tm) 2 Platform, Enterprise Edition
[mailto:J2EE-INTEREST@(protected)] On Behalf Of Ashutosh Bhardwaj
Sent: Tuesday, May 25, 2004 1:22 PM
To: J2EE-INTEREST@(protected)
Subject: Transactions
Can somebody throw some lighty on local and global transactions ? what
are shareable and unsahreable connections?
regards,
ashutosh
========================================================================
=== To unsubscribe, send email to listserv@(protected) and include in
the body of the message "signoff J2EE-INTEREST". For general help, send
email to listserv@(protected) and include in the body of the message
"help".
===========================================================================
To unsubscribe, send email to listserv@(protected) and include in the body
of the message "signoff J2EE-INTEREST". For general help, send email to
listserv@(protected) and include in the body of the message "help".
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<TITLE>Message</TITLE>
<META content="MSHTML 6.00.2800.1106" name=GENERATOR></HEAD>
<BODY>
<DIV><FONT size=2>
<P>The following is an excerpt from the URL </FONT><A
href="http://info.borland.com/techpubs/jbuilder/jbuilder8/enterprise
/transactions.html"><U><FONT
color=#0000ff
size=2>http://info.borland.com/techpubs/jbuilder/jbuilder8/enterprise
/transactions.html</U></FONT></A></P>
<P><FONT size=2>Local and global transactions</FONT></P>
<P><FONT size=2>When a single connection to a database exists, the enterprise
bean can directly control the transaction by calling commit() or rollback() on
the connection. This type of transaction is a local transaction. Using global
transactions, all database connections are registered with the global
transaction service, which handles the transaction. For a global transaction,
the enterprise bean never makes calls directly on a database connection itself.
</FONT></P>
<P><FONT size=2>A bean that uses bean-managed transaction demarcation uses the
javax.transaction.UserTransaction interface to identify the boundaries of a
global transaction. When a bean uses container-managed demarcation, the
container interrupts each client call to control the transaction demarcation,
using the transaction attribute set in the bean's deployment descriptor by the
application assembler. The transaction attribute also determines whether the
transaction is local or global.</FONT></P>
<P><FONT size=2>For container-managed transactions, the container follows
certain rules to determine when it should do a local versus a global
transaction. Usually a container calls the method within a local transaction
after verifying that no global transaction already exists. It also verifies
that
it isn't expected to start a new global transaction and that the transaction
attributes are set for container-managed transactions. The container
automatically wraps a method call within a local transaction if one of the
follow conditions is true:</FONT></P>
<P><FONT size=2>The transaction attribute is set to NotSupported and the
container detects that the database resources were accessed.</FONT></P>
<P><FONT size=2>The transaction attribute is set to Supports and the container
detects that the method wasn't invoked from within a global
transaction.</FONT></P>
<P><FONT size=2>The transaction attribute is set to Never and the container
detects that database resources are accessed. </FONT></P>
<P><SPAN class=683455808-25052004><FONT face=Verdana color=#000080
size=2></FONT></SPAN> </P>
<P><FONT face=Verdana color=#000080 size=2><SPAN class=683455808-25052004>Best
Regards</SPAN></FONT></P>
<P><FONT face=Verdana color=#000080 size=2><SPAN
class=683455808-25052004>Jaise</SPAN></FONT></P></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-- --Original Message-- --<BR><B>From:</B> A mailing list
for Java(tm) 2 Platform, Enterprise Edition
[mailto:J2EE-INTEREST@(protected)] <B>On Behalf Of </B>Ashutosh
Bhardwaj<BR><B>Sent:</B> Tuesday, May 25, 2004 1:22 PM<BR><B>To:</B>
J2EE-INTEREST@(protected)<BR><B>Subject:</B>
Transactions<BR><BR></FONT></DIV>
<DIV><SPAN class=390085007-25052004><FONT face=Arial size=2>Can somebody
throw
some lighty on local and global transactions ? what are shareable and
unsahreable connections?</FONT></SPAN></DIV>
<DIV><SPAN class=390085007-25052004><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=390085007-25052004><FONT face=Arial
size=2>regards,</FONT></SPAN></DIV>
<DIV><SPAN class=390085007-25052004><FONT face=Arial
size=2>ashutosh</FONT></SPAN></DIV>==========================================
=================================
To unsubscribe, send email to listserv@(protected) and include in the body
of
the message "signoff J2EE-INTEREST". For general help, send email to
listserv@(protected) and include in the body of the message "help".
<P></P></BLOCKQUOTE></BODY></HTML>
===========================================================================
To unsubscribe, send email to listserv@(protected) and include in the body
of the message "signoff J2EE-INTEREST". For general help, send email to
listserv@(protected) and include in the body of the message "help".
<p>
|
|
|
