Joe Nguyen

I am using all default configuration for IE 6.0. Do I need to make any modification?

What I did was clicking the back button 10 seconds after reading the content of the page. Does it expire that quick?

Note that right at this moment,I don't have any problem. That what I meant it occurs at certain time of the day.

I kept receiving this message after clicking the back button. It only occurs at certain hours of a day.

"Warning: Page has Expired The page you requested was created using information you submitted in a form. This page is no longer available. As a security precaution, Internet Explorer does not automatically resubmit your information for you.

To resubmit your information and view this Web page, click the Refresh button."

By keeping in the httpSession, you're tempting to use stateless session bean in place of stateful session bean; this practice increases overhead and have been considered to be bad practice (google).
It depends on where state's belong to. If it's belong to HttpSession, then it 's better be in the HttpSession. Otherwise, it's be in the stateful sb

I mean Itinerary has 1...many Segments. To calculate the price, the getPrice() method will be invoked on the component.

Congratulation

Did you have exactly one component diagram, one class diagram, and one sequence diagram?

Could you recomend a couples of good sites providing helpful component diagram tutorial? I did some google and got too many.

I just begin to do part II and would like to get people's opinions about the relationship between Itinerary and Segment.

Since Itinerary has 1...Segments and a Segment can be an Itinerary (in this case Itinerary has exactly 1 Segment), Itinerary can be viewd as a composite and Segment as a leaf. When a customer would like to change the existing Itinerary, Customer selects the segment to change. In order to change, the segment is deleted and the Prepare Itinerary Use Case is executed. Using composite relationship, the pricing would be easy to calculate.

You'll need to cast it back to Integer and call intValue() on it.

switch (((Integer)dno).intValue())

OK. In the case I presented Vector extends Object and Bar extends Vector ( all single inheritance).

Opps Typo: ideally is the same as (3

According to java API Class Object is the root of the class hierarchy. Every class has Object as a superclass. All objects, including arrays, implement the methods of this class. Java does not permit multiple inheritance, but it is not the case.
For instance:
(1) Class Foo extends Object{} //no compiling error
(2) Class Bar extends Vector{} // ideally is the same as (2) but with no compiling error
(3) Class Foo extends Object, Vector // copiling error

Does it mean java internally does permit multiple inheritance?

michelle.favoriteSport = "java";
or
michelle.setFavoriteSport ("java");
- where is the difference?
The writer of 'Person' has total access to the class, and may implement whatever he wants though.


The difference is at the place where the writer of 'Person' is not the same as the creator of the 'Person' instance. If the Person class is coderanch, everyone can create instances of the class; this is where unwanted side effects may take place.

You can achieve it in the following ways
1) subscribe to a timmer event which will notify your people compiling process every hours?
2) keep track of your last refesh time. If the currenttime - last refresh time > 1hr, recompile your people list.
3) create a thread and put it to sleep for an hour

I don't see how linklist could be an example in this case. If I have a read-only variable in an object which is stored in a linklist, I certainly don't want other objects of the same class to modify the read-only variable.