My new path

At last I started on my own path, still need to learn and do a lot. The first one a puppy is for Kaushik (As I told him, he would get my first painting) :) and its like the first painting as I had no exp in oil paint...anyways lots of complaints from him for that but a promise is a promise so I will not be correcting that painting even if I know its not tht much good...




The second one is for my wife...yeah my life I started realizing about oil painting...yeah its not that easy, this painting is copy right of a guy (I don't remember this id to be given over here) so I tried to do it as he has done but yeah he is a professional one n mine seems just a child started one, mmmm thats k for me....I have learned lots of details from this person's painting (thanks to him, sorry realy I haven't saved from where I have taken this painting).








The third is for Sudhir...my lungoti yaar....yeah he seems very impressed but frm my heart I know its just eye illussion if this painting is seen by any real artist he will defentliy kick me..for the mistakes I have done, but yeah I will b improving on that.

ORA-01005: null password given; logon denied

I was doing a simple POC of JDBC.
My system configuration is

Operating System : Windows XP
OS Architecture : x86
OS Version : 5.1
Database Version : Oracle Database 10g Express Edition Release 10.2.0.1.0 - Beta
Java Version : 1.5.0_16
JDBC Jar File : OJDBC5.jar

When I tried to run the program I was getting "null password given; logon denied", yeah I know the reason :) I cross checked that I have missed giving password but NO wait...I have given it correctly, but still I was getting "null password given; logon denied".

I searched net for any issues related to it, and found one blog where it says change the language settings, I tried it but had no success. So I went and saw was I using correct ojdbc5.jar file, looked like I was using correct jar and that too with correct version of JAVA but still I got the error. after struggling for 3 days I just thought to use the jar provided by ORACLE XE in %ORACLE_HOME%/lib, it contained ojdbc1.4.jar and ojdbc1_g.jar it says to use this jar with JDK1.4 but I was using 1.5 but still wanted to test it. so I went ahead and used 1.4 drivers instead of 5.jar, it just worked out...... :) but still have to figure out why I was getting "null password given; logon denied" when I was using ojdbc5.jar which should be used with JAVA 1.5.

Back reference in Hibernate

I was working on a bug (enhancement) in my project, where in I had to enhance one functionality which is purely written in JSF (some JS) to use the projects metadata framework. First I want to tell what this framework looks like (at high level).

Metadata framework (MTDFRM) its some thing like replicating or showing in UI form to the user for doing addition/editing/deletion of an row in DB (database).

Coming to the problem where it all started, below is the hibernate mapping of a table which I had move it to MTDFRM from conventional JSF:

<hibernate-mapping>
<class lazy="true" update="true" insert="true" table="HOLDER" name="Holder">
.......
.......
<set lazy="true" cascade="all" name="ParamsValues">
<key column="PARAMS_VALUES_SEQNO" null="true">
<one-to-many class="ParamsValue">
</one-to-many>
</key>
</set>
.......
</hbm>

There were 10 properties (including collections) but when I was running the project JSF was complaining about a property not found which was named as _paramsValuesBackref ("_" and "Backref" where appended to paramsValues, as I am like a new bee to the project I spent around 6hours finding which code modified the properties of the table mapping but I never serached in hibernate code, my mistake :(, but some how at last I was able to trace to a file which was appending one extra property to the metadata, it was org.hibernate.cfg.HbmBinder.

As per comments in the file of HbmBinder it says "for non-inverse one-to-many, with a not-null fk, add a backref!", which was perfect fit for the above properties which I had in my mapping file, so I had to add inverse="true" which made the backref no more to be added as extra properties in the metadata, as we know it also helps in telling hibernate that we should not propagate chances made at this collection end ie at ParamsValues end.

This blog doesn't say much about the usage of BackRef by hibernate, as I need to investigate the usage as how hibernate uses this property. Will be posting the finding (need to google or debug) in the next blog to come....

The mistakes I do & repeat it even if I know :)

I am a human :) (wow at last I think I am a human) in my job I do one big mistake, which I know about, I may be doing even more mistakes but I need to hunt them down someday.
So about this mistake, I don't know what technical word is given to this habit, its like this say I am working on a problem (off-course its about my job) and as usual I don't know anything about it, I try to hunt it down as soon as possible but when I am stuck the usual thing normal people do is take help from a person who already knows about it but me me....I don't do this but instead I hunt around and this goes like a circle, few problems yeah I do get solutions, its not gr8 because already ppl know about this and me just discovered, but my inner feeling is like "wow I did some thing gr8" this feeling is a evil in disguises to me as for other problems I hunt and I can't get the solution on time but to get this gr8 feeling I try and try but at the end it like, the problem which can be solved by a person how knows things better can do it in say some 16hour I spent the whole week :( ie 8hours * 5 (40 hours) but still I am now where.......
This is my biggest mistake, I do all over then I release but then latter when I am into problems I forget or negelate my mistake and I am allover again doing the same old mistake :)
The other mistake I do is like, when I am looking for solution for problem 'A' I hunt it down, but during this period if I see other things like 'B', 'C'.....I get involved in tooking into it for getting knowledge about them and I just get deviated from problem 'A'.
I need to over come this things, hope I do and soon as I am getting nearer to 4years of work exp I need to be more smart and more control on my self taking in to account of any problem (technically).

Dos and Don'ts

This is much for myself & if it helps others its good :

1. Code to interface, mmmm still need to get habituated with this.
2. Write test cases.
3. Never mutate the object passed by the parameter ie when we get list as an method parameter do not alter the list in that method , and when we need too then just make a local copy of it and work on the locally created object.
4. When wrapping up the exception do wrap with cause ie try {} catch (SomeException e) { throw new WrapException(e.getMessage()) {}...never do this, we are eating up the actual cause but instead do "throw new WrapException(e)" in the catch.
   
5. Avoid String splitting for business logic flow. like String str1 = getSomeText(); if("Target".equals(choice.split("-")[0].trim()) { //do this....} else {// do that...}

Some other things I want to remember and I forget all the time

1. Apache Tomcat is servlet container, it implements java servlet & jsp spec and provides pure java HTTP web servlet environment.
2. 'Apache Web Server' is C-Lang based HTTP web server.
   

technical blog by my collegues

My colleagues blog at http://pitfalls.wordpress.com which is a good stuff to go through...this ppl r technical gurus... :) gr8 to have thm as my colleagues...

sw architecture links

Nowadays I am going through Hibernate, JSF, Springs and functional requirements of my current project. Going through this stuff all at a time is not good....this I got to know after doing it :)

Today I got a good links on Software Architecture, this link is of an google group http://groups.google.com/group/codingthearchitecture?lnk=srg and this one by Markus Voelter http://voelterblog.blogspot.com/

Good article in to JVM internals

This link provides good information about JVM internals.

http://www.artima.com/java/

Books to read:

• Extreme Programming explained by Emrace Change
• Effective Java by Joshua Bloch
• Design Patterns by the Gang of Four
• Concurrent Programming in Java by Doug Lea
• The Pragmatic Programmer: From Journeyman to Master
• Better, Faster, Lighter Java by Brue A. Tate & Justin Gehtland
• Java Threads by Scott Oaks, Henry Wong

and still to come.....

Cricket ball rolling

After all most 2years I was back with ball (cricket ball, 3rd Sat March 08) bowling in nets, I enjoyed every moment of it. SeeBeyond (Sun microsystems) was my first company and there I started playing cricket and then when I changed (joined Intoto) there was no such thing, just work!. now as I joined a new one (Pramati) things seems good over here...people love cricket and they play too.
After having the practice session we had team breakfast and there was another match scheduled on Sunday (4th). I felt great, but then I had pains (not that much), I thought it will go away. On the next day i.e. Sunday we played the match and off-course we won. I came back to home and went to sleep only to find myself in great pains when I woke up :(, I had to take leave on Monday.....my first leave in Pramati :)

Coming back after long time

It has been very long time....since I have posted any, so long that I am working for 3rd company. Hope from now on I will consistent.