BRIDGING JAVA OBJECTS AND RELATIONAL DATABASES
BRIDGING
JAVA OBJECTS AND RELATIONAL DATABASES
This release brings to major changes:
due to a trademark conflict I had to change the name of the project. It is now called ObJectRelationalBridge. The new name is not as smashing as the old one but more precise. So I think it's a thing we can adopt to.
In the long time since the last release (6 weeks !) I
designed a distributed architecture for OJB. This new architecture
splits OJB into two parts: a client component consisting of the ODMG
implementation (if you want to use it) and a
PersistenceBrokerClient. And on the other Side a
PersistenceBrokerServer. The PersistenceBrokerClient implements the
PersistenceBroker interface but it is a Proxy that delegates all
calls to the PersistenceBrokerServers. In fact it can delegate calls
to an arbitrary number of servers to allow load-balancing.
The
PersistenceBrokerServer is a TCP/IP based multithreaded Server (in
fact it's based on a simple HTTP server). The Server maintains a
pool of PersistenceBrokerImpl's that do the real database work. All
these worker objects share the same ObjectCache.
The concept is
not fully implemented (distributed lock handling is not yet
supported) but it is complete enough to give it a try.
I wrote a
little intro that
will help you getting started with the Server architecture.
Be sure that a JDK 1.2 or later is properly installed on your
machine.
If you are working under windows you will need to adjust
the batch file build.bat. The variable JAVA_HOME
must point to the base directory of your JDK. For example: set
JAVA_HOME=C:\jdk1.3
If working under
GNU/Linux you will need to set execute rights for build.sh by chmod
+x build.sh
After running build[.sh|.bat]
doc you will find further information following the two
links below:
The PersistenceBroker is quite stable, only minor Modfications and bug fixes are to be expected
The ODMG interface is now feature complete !
Multisession capable Objectbroker (implemented as a multithreaded TCP/IP socket based server)
Distributed lock handling
built in support for major RDBMS (Oracle, DB2, etc.)
Graphical tool for building Object / Relational mappings (A volunteer is working on this !)
JDO compliant interface
documentation
...