Java school Project

DJT · Post by **DJT** » 30 Aug 2005, 14:32

Jeez, take a look at what we have to do for our Gr 10 Computer studies project.

GRADE 10 CELL PHONE PROJECT

You are required to generate /simulate a cell phone. The cell phone must have the basic functions of sending and receiving telephone numbers. These numbers should include landline and cell numbers. In addition, include a SMS function of sending and receiving messages.

You will need to do:

1. create a class that contains the following attributes
1.1. ownNumber
1.2. incoming number
1.3. outgoing number
1.4. blocked number
1.5. SMS number
1.6. Engaged
1.7. Time
1.8. Cost_per_minute

(for the I want to do learner ? how about determining if the system is prepaid etc)

You will need to decide what data types you need for the attributes

2. The following methods
2.1. A set and get method for each attribute
2.2. A method that converts the time to hours, minutes and seconds
2.3. A method that determines the cost of the call.
2.4. ToString method
2.5. A print statement about the call, length of call.

3. A main method
That instantiates a Cell phone object and which simulates the front end of cell phone

4. NOTE: Generate random number for the incoming, outgoing - calls, cost and time and the engaged signal

No idea where to start on this. We were given a weird class that generates rendom phone numbers, but apart from that, nothing.

Stevo · Post by **Stevo** » 30 Aug 2005, 14:34

ouch ........

Fishzn · Post by **Fishzn** » 30 Aug 2005, 14:38

Dude, i did this for an assignment in 1st year varsity. It was slightly more complex than what you have there, but still performed all those functions. If i can find it, i will send it to you!

rustypup · Post by **rustypup** » 31 Aug 2005, 07:57

Project wrote: 1.1. ownNumber
1.2. incoming number
1.3. outgoing number
1.4. blocked number
1.5. SMS number
1.6. Engaged
1.7. Time
1.8. Cost_per_minute

Code: Select all

public abstract class Phone
{
private String ownNumber, incommingNumber, outgoingNumber, blockedNumber, SMS number;
private boolean engaged;
private java.util.Date callStart;
private BigDecimal costPerMinute;
}

i)Numbers stored as Strings...quickest route, unless you want to discuss regex...
ii) engaged is digital - either true/false..
iii) Using java.util.Date, calls to a getDuration() type method returns deviation from start to now... or you could store the system time as a long...
iv)BigDecimal... using this wrapper will help in not having to deal with NaN or infinity issues when engaged in double precision math...

Project wrote: 2.1. A set and get method for each attribute

Standard practice in any java app.... it's how things work...

Code: Select all

public void setPhoneNumber(String numbr)
{
    ownNumber = numbr==null?ownNumber:numbr;
}
public String getPhoneNumber()
{
    return ownNumber;
}

HINT: always validate params... this will save you a lot of unnecessary headaches around silly NPEs..... if the turnary *?* bugs you let me know...

Project wrote: 2.2. A method that converts the time to hours, minutes and seconds

Sure..why not... I'm sure the odds are that no codemonkey has ever needed this before, hence its exclusion from the jAPI... man... who teaches this stuff?

my favourites being...

Project wrote: 2.4. ToString method
3. A main method

someone did their homework... the first is default inherited from Object, but you will almost *always* override in order to make sense of anything... the second you cannot do without if you want the app to run...

....if this doesn't help... give us a shout..

Law · Post by **Law** » 31 Aug 2005, 08:19

Code: Select all

private java.util.Date callStart;

Do u really think that is nessecary. just easier to use Time as a float. then use Time = System.currentTimeMillis();then when the calls finish Time = (System.currentTimeMillis()-Time)/1000. then you got the call length in seconds. Just seems easier.

rustypup · Post by **rustypup** » 31 Aug 2005, 08:29

Law wrote:
Code: Select all
private java.util.Date callStart;
Do u really think that is nessecary. just easier to use Time as a float. then use Time = System.currentTimeMillis();then when the calls finish Time = (System.currentTimeMillis()-Time)/1000. then you got the call length in seconds. Just seems easier.

err..long .. not float

... that's why i said store start time as a long.. but then that's precisely what the java.util.Date class does, while at the same time including all those handy minute/hour/day functions attached along with being implicitly understood by java.util.Calendar...

long just seemed so boring... the API is chock-full of alternmatives to which the average student is never exposed... just seemed a good point at which to start the introduction...

Law · Post by **Law** » 31 Aug 2005, 08:45

yeah it is long. BUt that is just a waste of performance creating a new object. NOOB

rustypup · Post by **rustypup** » 31 Aug 2005, 09:15

Code: Select all

public class NooBScanner() implements Serializable
{
     public static enum CONSTANT_NOOBS{
          LAW("Law", "Master of the Pubic kNights"), 
          BOB_MUGABE("Satan", "Raging Elton John fan"), 
          AUSTIN_POWERS("jamin_za", "Brick-less");
           
          private String descript, nick;
          
          CONSTANT_NOOBS(String nck, String descr)
          {
                  nick = nck;
                 descript = descr;
          }
          public String getNick()
          {
                return nick;
          }
          public String getDescription()
          {
                return descript;
          }
      }
      //no point instantiating...
      private NooBScanner()
      {     
            super();
      }
      public static boolean isNoob(String posterNick)
      {
           /*for(CONSTANT_NOOBS cn:CONSTANT_NOOBS.values())
                if(cn.getNick().equals(posterNick))
                      return true;
           return false;*/
           if(posterNick.toLowerCase().indexOf("law")>=0)
                return true;
           return false;
       }       
}

found this hiding on the server...

amdretard · Post by **amdretard** » 31 Aug 2005, 16:41

Djt and i are doing the same thing

Anyway how do i randomly generate letters or even word to simulate a SMS

rustypup · Post by **rustypup** » 31 Aug 2005, 16:47

amdretard wrote:Anyway how do i randomly generate letters or even word to simulate a SMS

Math.random()???

amdretard · Post by **amdretard** » 31 Aug 2005, 16:51

ok how do i get that to be just letters

Law · Post by **Law** » 31 Aug 2005, 16:53

Well create an array of strings as sms' Then you at least have proper msgs
then for numbers use

Code: Select all

Math.random()

This generates a random number between (0;1) -> note the round and not square brckets

so you can times it by ten to make a number from 1-9

This makes a String that makes a number

Code: Select all

 String number="";
for(int i=0; i<10; i++)
{
  number +=""+((int) Math.random()*10);
}

then to select from the array

Code: Select all

int selectedMsg = (int) Math.random()*messageArray.length()

if you want generate a random number multiply by 26 then add 59(think to get letters

amdretard · Post by **amdretard** » 31 Aug 2005, 16:54

Why dont one of you guys do this for ME

amdretard · Post by **amdretard** » 31 Aug 2005, 16:55

Why dont one of you guys do this for ME

Since you guys are having a fight over who is best why dont you both do it and then i will judge by using that one

Law · Post by **Law** » 31 Aug 2005, 16:59

caues it's piss easy. AND

you can do it! bite his %$#@en head off!

And i know i'm better newayz0rZ

amdretard · Post by **amdretard** » 31 Aug 2005, 17:06

well i tried

Anyway we havent learnt all this time stuff and we have to create a random time for it
so from creating the random time in seconds how do i convert that to h m s in short easy way

rustypup · Post by **rustypup** » 31 Aug 2005, 17:08

1000ms->1s
60s->1min
60m->1hr
24hr->1day

now class.. who can tell me how many days in a year...?

amdretard · Post by **amdretard** » 31 Aug 2005, 17:13

er 45 LOl

i mean in terms of java what algorithm and then to work out cost of that phone in terms of a cost being an object

Law · Post by **Law** » 31 Aug 2005, 17:15

well if you did it my way. you can divide by 60 to get mins and divide by 60 again to get hrs> if you want hrs mins sec

you have total time in secs say int TotSec

mins = TotSecs/60;
hrs = mins/60

then in order

int secs= TotSec-mins*60;
min=mins-hrs*60;

you may think wtf because i'm dividing by 60 then multipling i'll get the same number. But thanks to my good friend integer division it works

amdretard · Post by **amdretard** » 31 Aug 2005, 17:18

How do it get it not to give me decimal but just remainders

Law · Post by **Law** » 31 Aug 2005, 17:18

what ide are you using??

amdretard · Post by **amdretard** » 31 Aug 2005, 17:20

Ready to program jdk 1.2

Remind me which is the ide

Law · Post by **Law** » 31 Aug 2005, 17:23

like int five = 45%10;

you can also use that to get secs and mins

secs = TotSec%60
mins = mins%60

but only after youve calculated the hrs

so TotSecs = 10000;// sec
mins = 166;
hrs = 2;
then secs = TotSecs%60;
mins = mins%60;

IDE = integrated development enviroment

It's the program you code in

rustypup · Post by **rustypup** » 31 Aug 2005, 17:31

yep... %==modulus == remainder...

but then again,

seriosuly get the latest Eclipse... or netbeans...

also, jdk1.2!?? nooooooo.....

<edit... someday...soon... i'm gonna hurt myself...>

Law · Post by **Law** » 31 Aug 2005, 17:34

1.2 is kewl it closer to 1 than 1.5

Yeah you should geta later JDK. esp since it's free

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