Freya.no » certification http://wp.freya.no Knowledge is power Mon, 06 Feb 2012 19:56:41 +0000 en hourly 1 EJB 3.0 Roles http://wp.freya.no/2010/03/ejb-3-0-roles/ http://wp.freya.no/2010/03/ejb-3-0-roles/#comments Thu, 04 Mar 2010 19:14:18 +0000 Tatyana http://wp.freya.no/?p=619 I had some difficult time understanding all the roles regarding EJB3. Here is an easy-to-remember description of these roles that I found here.

Imagine a factory producing computers:

Bean Provider:
Chip manufacturer. On the chip, there will be a label with “Warranty void if removed” the chip has the logic and the label sets a Role. If you are not authorized to repair it, warranty voids. (i.e. you cannot access the internal chip if you are not in the role of “Warranty Repair Person”.)

Application Assembler
Mainboard assembler. It takes various chips and puts them on the mainboard. If any additional resistor or cable are required, it will put everything togheter to have something that is some kind of working unit but requires additional assembling.

EJB Server Provider
The EJB Server provider is the Computer Case manufacturer providing a case with a power supply. Is a container for the mainboard

Deployer
As every computer case is different and power voltage vary country by country, the Deployer makes sure to adapt the mainboard to the working environment. In this case adjusts the Voltage on the power supply, and connects the cables. At the same time he will define who are the person allowed to repair it (i.e. provide a list of authorized repair centers)

Persistence Provider
the persistence provider could be the network card company that provides the driver to connect to a network.

System Administrator
Is the person in charge to install the operating system and do necessary configuration changes to the OS to connect to the server, and will make sure to monitor that everything is working fine.

More about Enterprise Java Beans 3.0 and Sun Certified Business Component Developer (SCBCD) certification here.

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]]> http://wp.freya.no/2010/03/ejb-3-0-roles/feed/ 0 Java conversions and 7 Golden rules of widening, boxing & varargs http://wp.freya.no/java/java-conversions-and-golden-rules-of-widening-boxing-varargs/ http://wp.freya.no/java/java-conversions-and-golden-rules-of-widening-boxing-varargs/#comments Tue, 16 Feb 2010 19:31:43 +0000 Tatyana http://wp.freya.no/?p=510 Here is a very useful java conversion table that I’ve created while preparing for the Sun Certified Java Programmer exam.

primitives conversion

Java primitive conversions table

And here is a complete overview of the Golden rules of widening, boxing & varargs:

1. Primitive Widening > Boxing > Varargs.
2. Widening and Boxing (WB) not allowed.
3. Boxing and Widening (BW) allowed.
4. While overloading Widening + vararg and boxing + vararg are mutually exclusive of each other.
5. Widening between wrapper classes not allowed
6. Widening+varArgs & Boxing+varargs are individually allowed (but not allowed in overloaded version of method)
7. Boxing+Widening is preferred over Boxing+Varargs.

More explanation here.

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]]> http://wp.freya.no/java/java-conversions-and-golden-rules-of-widening-boxing-varargs/feed/ 1 Java certification preparation tools http://wp.freya.no/2010/02/java-certification-preparation-tools/ http://wp.freya.no/2010/02/java-certification-preparation-tools/#comments Sun, 14 Feb 2010 21:55:56 +0000 Tatyana http://wp.freya.no/?p=469 SCJP – Sun Certified Java Programmer
SCBDC – Sun Certified Business Component Developer

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