Apr 15
An object by itself is intensely uninteresting.Objects contribute to the behavior of a system by collaborating with one another.One of relationship aspects between Objects can be represented by Association.
When we bring in Cardinality in Association we get One-to-One, One-to-Many and Many-to-Many.In later two One-to-Many and Many-to-Many we use Collection to represent many Side.For example: An Order have many OrderDetail’s.
We have these associations represented in Relational DBMS using foreign keys.So from any O-R framework we expect that to take care of these associations in smartest way possible.As these can easily become a performance bottle neck for the application.Some time you may end up loading lot of Data into memory, and sad part is you are never going to use them. Continue reading »
Jun 19
Issues in porting existing Applications on Clustered Environments
The ideas mentioned below are based on the practical experience of porting an existing application over a clustered environment. The work around and the solutions mentioned below should not be taken as “best practice guidelines” but possible quick fixes which may be needed to make sure that the application can run in a stable fashion without causing serious issues though with some trade off on scalability.
Environmental Setup of Cluster
The typical cluster being discussed here is not application severs cluster where the App servers are started in a clustered mode. Here multiple instances of App servers were started on different machines connecting to the same DB and a load balancer was placed in front of them for receiving requests and forwarding it to one of the App Server instances. Continue reading »
May 05
A smarter brain than mine at work, pointed out this interesting article to me.
Java String Performance testing
It talks about string performance testing. I could make sense of most of the observations made in this test and thought of sharing it.
In short the test compares string operations like “+”, “new String” and then “+”, “+” with fields and then StringBuffer append. One of the conclusions of the test is
the ‘+’ operator is not evil when used with Strings
I agree with this statement and a look at the generate byte code pretty much convinces us of so. But, a word of caution here, it always makes sense to check this on our target compiler before committing to it. Continue reading »
Apr 28
This is a small article which explains the steps to register custom fonts with Apache FOP engine. Registering custom fonts with Apache FOP becomes important in the context of Internationalization, especially if one wants to display CJK languages in the PDF being generated. The context of this article is when fop is being used in other application for generating PDF for some XML data.
Step 1:
Install the required fonts to your OS. E.g. for Windows the fonts should be installed using the Control Panel or by copying the fonts to Windows Directory\Fonts.
If one is looking for Chinese/Korean Language, MS GOTHIC is a good font carrying a wide range of symbols.
The font can be in a standalone ttf (TrueType Font) file or a ttc (TrueType Collection) Continue reading »
Apr 07
The main idea of the presentation is not to discuss how Internationalization is done in Java but to highlight some of the problems which one comes across while developing an internationalized application in Java. Most of the observations listed below are based on the personal experience while trying to internationalize a Java based Web Application. Attendees are expected to have basic idea about the features provided by Java to support Internalization. A good resource for the basic reading is OReilly – Java Internationalization.
Continue reading »
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