gaining confidence...

When we write a program, we should always write modules to allow us to see the health of the module, such as connectivity to JMS servers, open office instances ...

provide admin functionality but make it as inaccessible as possible.

Simplication via Polyglot

Radical Simplification Through Polyglot and Poly-paradigm Programming

*less code
*biz logic and impl separation (DSL)

imutable
nothing to sync
no locks semaphores mutexes

data stable, but a lot of functions use list, map, filter, fold/reduce (cloud computing)

adding types, few functions, use OO inheritances

declarative vs imperative

erlang
no mutable variables & side effect
IPC optimised msg passing (actor model)
lightweight & fast process

*less code 
*model domain as close as possible 
*declarative concise bug free 
*no mutable variables & side effect

-mocking dependency 

“FIRST class” test cases

Make “FIRST class” test cases (Fast, Independent, Repeatable, Small and Transparent)

Fast. Your test cases should be very fast to execute, every time you want to run all of them it shouldn’t take more than a few seconds for an small application.

Independent. You should be able to run your test cases in any order.

Repeatable. The result of the test case should be always the same, no matter how many times you have executed it before.

Small. Small test cases are easy to understand and change, are also likely to be faster.

Transparent. It should be clear what the purpose of each test case is.

from How to write a good test case: 5 tips to write better test cases

inverse vandals

"Basically, inverse vandals dont care about their work and its impact on the lives of users and the many others affected by their work, which is a pity. Software has a sort of magic in itself, and interactive software provides a concrete, vivid example of such a magic. Whether you are a teenager playing a video game or an old guy fiddling with an early computer in your garage, there was probably a moment in your life when you were totally amazed by a piece of software - otherwise you would probably have chosen another career."

Wiley Professional Java User Interfaces p. xxiiv

sql to_date() to_char() removal for java

Oracle to_date()
select db_fieldname from db_table where db_timestamp_field = to_date(?, 'dd-mm-yyyy');

replace the to_date(?, 'dd-mm-yyyy') function with a ?

select db_fieldname from db_table where db_timestamp_field = ?;

then using

SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
Timestamp result = new Timestamp(sdf.parse(inputdate,new ParsePosition(0)).getTime());

prepareStatement.setTimeStamp(1,result);


Oracle to_char()

select * from table where to_char(db_timestamp_field, 'dd-mm-yyyy') = ?;

replace to_char(db_timestamp_field,'dd-mm-yyyy') with trunc(db_timestamp_field)

select * from table where trunc(db_timestamp_field) = ?;

SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
Date javaDate = sdf.parse(inputdate);
java.sql.Date sqlDate = new java.sql.Date(javaDate.getTime());

prepareStatement.setDate(1,sqlDate);

accumulator

I would need to scan a directory, take note of each of the file size, and do a count on how many files there are with a particular size.

file size is long
count is int

so i have one array to keep track of file size
another array to keep the int count

so once i have a file size, i would check through the array of file size, to see if it is the same, if yes, i remember the index and take the value from the count array plus one and put back in. The data structure which i used initially was 2 arraylist.

for sizeArray
  if sizeArray[i] is filesize
    take countArray[i]+1
    addedFlag to false

if addedFlag
  sizeArray[max] is filesize
  countArray[max] is 1

it looks awfully complicated, so i changed the 2 array into a hashtable
the long value will be converted to a string object.

if hashtable has fileSizeString
  currentCount is hashtable get fileSize
  hashtable put fileSizeString, currentCount+1

hence making the code a lot more shorter.

Conditional Complexity

see Conditional Complexity

public function validateObject(object:Object):void {
if (conditionA || conditionB) {
throw new ObjectValidationError(object);
}
if (conditionC || conditionD) {
throw new ObjectValidationError(object);
}
if (conditionE || conditionF) {
throw new ObjectValidationError(object);
}
// and many more if-statements
}

---

public function validateObject(object:Object):void {
if (conditionA || conditionB) {
invalid(object);
}
if (conditionC || conditionD) {
invalid(object);
}
if (conditionE || conditionF) {
invalid(object);
}
}

protected function invalid(object:Object):void {
throw new ObjectValidationError(object);
}

---

public function validateObject(object:Object):void {
validate(conditionA && conditionB, object)
validate(conditionC && conditionD, object)
validate(conditionE && conditionF, object)
}

protected function validate(isValid:Boolean, object:Object):void {
if (!isValid) {
throw new ObjectValidationError(object);
}
}

Vector to HashMap pattern

motivation: i recently discovered a bug via vector which resulted in the validation incorrectly checked.

Some Action

Vector v = new Vector();

v.add(request.getParameter("name"));
v.add(request.getParameter("address"));
v.add(request.getParameter("telephone"));

Some Manager

v.get(0);
v.get(1);
v.get(2);

can be replaced with

HashMap hm = new HashMap();

hm.add("name",request.getParameter("name"));
hm.add("address",request.getParameter("address"));
hm.add("telephone", request.getParameter("telephone"));

later on

hm.get("name");
hm.get("address");
hm.get("telephone");

this is much less error prone then refering via vector indexes. you can add new parameters without affecting the orders of the parameters also. String should be extracted out into a constants class to obey the principles of DRY.

Ternary operator pattern (aka inline conditions)

ternary operator
String id = request.getParameter("aaa")==null? "" : request.getParameter("aaa");

can be refactored to
String id = request.getParameter("aaa");
if(id==null) id ="";

which can be furthered reduce to

String id = Utility.isNull(request.getParameter("aaa"));

public String isNull(String input){
if(input==null) return "";
return input;
}

becoming a better coder...

things that might help you become a better coder

[Dont repeat yourself][1]

[Command-query separation (CQS)][2]

[Defensive programming][3]

[S.O.L.I.D.][4]

[Code Smell][5]

[Smells to Refactorings][6]
Patterns & Anti-Patterns

[Software Craftsmanship][7]

[Testable code drags OOP into Functional Programming][8]
[Writing Testable Code][9]
[How to Write 3v1L, Untestable Code][10]
[Design by Contract][11]

[1]: http://en.wikipedia.org/wiki/Don't_repeat_yourself
[2]: http://en.wikipedia.org/wiki/Command-query_separation
[3]: http://en.wikipedia.org/wiki/Defensive_programming
[4]: http://mmiika.wordpress.com/oo-design-principles/
[5]: http://en.wikipedia.org/wiki/Code_smell
[6]: http://www.industriallogic.com/papers/smellstorefactorings.pdf
[7]: http://en.wikipedia.org/wiki/Software_Craftsmanship
[8]: http://noss.github.com/2009/02/21/testable-code-drags-oop-into-functional-programming.html
[9]: http://googletesting.blogspot.com/2008/08/by-miko-hevery-so-you-decided-to.html
[10]: http://googletesting.blogspot.com/2008/07/how-to-write-3v1l-untestable-code.html
[11]: http://en.wikipedia.org/wiki/Design_by_Contract

little thoughts

you can have a very nice plan, but terrible piece of codes.

you can have the only documentation as the codes...

or you can do fast iterations, so that we (software engineers) help the user visualise what they want. Show them immediately quick and dirty prototype. Be ready to throw them away. This helps to converge to a commonality point.

quotes

if i dont look good, i dont think you will looked very good too...

but if i looked good, i am sure you will also looked good.

if the team dont look good, i dont looked good.

if the team looked good, we will look good too...


stakeholder...
decision maker...
middle man...
my client...
my team mates aka internal customer ...

environmental ideas

replace bend pipes with straight pipes

throttle server fans

increases air con temperature

a pot that reduces heat wastes. (invented in taiwan)

| |
| |
| |----| |
+---|fire|---+

encapsulate and fully cover the flame...

random words

The only documentation is code...

if I dont look good, you probably wouldnt looked very good too...

codes should be free...

Scolding generates bad karma. explain why not, what is the implications. 1st time let it off, subsequently then take discplinary actions.

the more you restrict, the more precious it becomes.

the more you give, the less it becomes a critical issue.

improper handover is sad, it means 2 person messed up as a professional.

a little quote

A failed project doesnt look good on anyone. it brings out the worst in everybody.

agility and software engineering is 2 different process for different kind of constraints projects. Cheap, fast, quality triangle? cheap but heavy design doc with long turn around time doesnt go togother with fast. quality, writing JUnit codes will turn up 50% of the project time.

know who are the stake holders... are they the decision maker?

just a little thought...

to know and to abuse is 2 different things ...

Information Theory, Inference, and Learning Algorithms

http://www.inference.phy.cam.ac.uk/mackay/itila/

how to find a keyword within an entire project

Place the below mfind.bat within your path such as c:\windows\system32

usage:
mfind "String title"

====mfind.bat====
@echo off
for /f "tokens=*" %%a in ('dir /b /s *.java') do find %1 "%%a"

Source Control HOWTO

Source Control HOWTO

passionate

You got the job because the boss thought you could contribute. Translation, you potentially have a mutually profitable future. Be passionate about your job and take pride in doing it well.

The Ascent of Humanity

http://www.ascentofhumanity.com/

Higher-Order Perl

http://hop.perl.plover.com/book/

Small Memory Software

http://www.cix.co.uk/~smallmemory/book.html

a recommended reading to write smaller programs

Ada

http://en.wikibooks.org/wiki/Ada_Programming

check out wikibooks.org natural science, social science, computing, humanities, arts books.

Structure and Interpretation of Computer Programs

http://mitpress.mit.edu/sicp/
a book on scheme

online: Dive Into Python book

http://diveintopython.org/