New to Java...Tough program to write I think...

Alright, I have a problem. I have never coded in java before, but a teacher wants a program written that is too much for html/php/VB to handel, and a friend suggestion I use java.
my problem is that I have never coded in Java before, but supposidly because its object oriented, the language should make the program easier to write.
The program is a "Group Generator"
Anyway, here is what the teacher wants:
Step 1) Program Asks user how many students are in his class, and how many students he wants in each group
Step 2) Program Asks user the names of all X students
Step 3) Program makes a list of every combination of groups that can be made out of these X people (never repeating 2 people in a group)
Step 4) Program outputs results
Here is a quick example because I know its confusing
10 kids in my class, groups of 2
Group Set 1:
1: AB
2: CD
3: EF
4: GH
5: IJ
Group Set 2:
1: AC
2: BD
3: GF
4: IH
5: EJ
and the program would keep finding sets of unique grounds...but A will never be grouped with B again, or C again...so the ammount of group sets is actually quite low.
Anway, this isnt for a grade or anything, its just something some teacher wants and I think would help teachers a bit in forming unique grounds of kids....
Any input or ideas would be GREATLY appriciated :-)

Alright, I have a problem. I have never coded in java
before, but a teacher wants a program written that is
too much for html/php/VB to handel, and a friend
suggestion I use java.HTML is markup, so it won't be of much use. However, PHP, VB, and a host of other languages can handle this easily. Write it using the language with which you are comfortable.
If you want to learn Java, however, here are some good resources...
Your First Cup of Java - http://java.sun.com/docs/books/tutorial/getStarted/cupojava/index.html
Essentials, Part 1, Lesson 1: Compiling & Running a Simple Program - http://java.sun.com/developer/onlineTraining/Programming/BasicJava1/compile.html
The Java Tutorial - A practical guide for programmers - http://java.sun.com/docs/books/tutorial/
New to Java Center - http://java.sun.com/learning/new2java/index.html
How To Think Like A Computer Scientist - http://www.ibiblio.org/obp/thinkCSjav/
Introduction to Computer Science using Java - http://chortle.ccsu.ctstateu.edu/CS151/cs151java.html
The Java Developers Almanac 1.4 - http://javaalmanac.com/
JavaRanch: a friendly place for Java greenhorns - http://www.javaranch.com/
jGuru - http://www.jguru.com
Object-Oriented Programming Concepts - http://java.sun.com/docs/books/tutorial/java/concepts/
Object-oriented language basics - http://www.javaworld.com/javaworld/jw-04-2001/jw-0406-java101.html
Don't Fear the OOP - http://sepwww.stanford.edu/sep/josman/oop/oop1.htm
Books:
Bert Bates and Kathy Sierra's Head First Java - http://www.amazon.com/exec/obidos/tg/detail/-/0596004656?v=glance
Bruce Eckel's Thinking in Java (Free online) - http://mindview.net/Books/DownloadSites
Joshua Bloch's Effective Java - http://www.amazon.co.uk/exec/obidos/Author=Bloch,%20Josh
Java Design: Building Better Apps and Applets (2nd Edition) - http://www.amazon.com/exec/obidos/tg/detail/-/0139111816/qid=1101309882/sr=8-7/ref=sr_8_xs_ap_i7_xgl14/104-6417153-1511164?v=glance&s=books&n=507846

Similar Messages

Brand New to Java and Programming

I'm brand new, ( RAW ) to software programming at this time. I'm starting from scratch, I work on a Help Desk for the government so I can perform some software functionality but nothing as far as programming.. I would like recommendations for someone starting out brand new.. Books to read (JAVA for Dummies?) any beginner courses? What steps would you take if you were starting out brand new as I am myself.. Thanks..
PS, I plan on taking courses after I get the beginning stuff out of the way, just don't want to go in with no knowledge base..

For a nice list of stock answers: The One to Torment Newbies with
Sun's basic Java tutorial
Sun's New To Java Center. Includes an overview of what Java is, instructions for setting up Java, an intro to programming (that includes links to the above tutorial or to parts of it), quizzes, a list of resources, and info on certification and courses.
http://javaalmanac.com . A couple dozen code examples that supplement The Java Developers Almanac.
jGuru. A general Java resource site. Includes FAQs, forums, courses, more.
JavaRanch. To quote the tagline on their homepage: "a friendly place for Java greenhorns." FAQs, forums (moderated, I believe), sample code, all kinds of goodies for newbies. From what I've heard, they live up to the "friendly" claim.
Bruce Eckel's Thinking in Java (Available online.)
Joshua Bloch's Effective Java
Bert Bates and Kathy Sierra's Head First Java.
James Gosling's The Java Programming Language. Gosling is
the creator of Java. It doesn't get much more authoritative than this.

New to Java. Want to write a simple applet for a mobile phone.

Hello,
I want to write a simple java applet for a mobile phone. currently I am in the stage of thinking about whether this is possible in a timeframe of about a month. I have very little java experience from a while back so I'm pretty much starting from scratch.
All I want is an applet that lets you send 2 or 3 variables to an online server. The server will then reposition telescopes.
All i'm concerned with is the mobile phone part, which doesn't have to be secure or impressive. Just a simple interface.
Ideally it should work on my nokia 6070, which occording to the official specs has the following java technology:
MIDP 2.0
CLDC 1.1
JSR 120 Wireless Messaging API
JSR 135 Mobile Media API
Nokia UI API
(I don't know what any of this means but am a good learner).
Can anyone offer me any advice? Is this possible in my timeframe? where should I start? I need a editor and compiler also (I'm using windows XP).
Many thanks and kind regards,
Jason

Actually it is working on my phone now.
I changed the target platform in the wireless toolkit settings to MIDP 1.0
Now to create the fields coordinate fields etc. I don't have much of a clue really.
Current I have:
import java.io.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
public class AtmosMIDlet extends MIDlet implements CommandListener
Form WelcomeForm = new Form("AtmosMIDlet");
StringItem WelcomeMes = new StringItem(null, "Please enter coordinates:");
TextField Longitude = new TextField("Longitude", "", 3, TextField.NUMERIC);
TextField Lattitude = new TextField("Lattitude", "", 3, TextField.NUMERIC);
public AtmosMIDlet()
try
ImageItem logo = new ImageItem(Image.createImage("/logo.png"));
WelcomeForm.append(logo);
catch (java.io.IOException x)
throw new RuntimeException ("Image not found");
WelcomeForm.append(WelcomeMes);
WelcomeForm.append(Longitude);
WelcomeForm.append(Lattitude);
WelcomeForm.addCommand(new Command("Exit", Command.EXIT, 0));
WelcomeForm.setCommandListener(this);
public void startApp()
Display.getDisplay(this).setCurrent(WelcomeForm);
public void pauseApp() {}
public void destroyApp(boolean unconditional) {}
public void commandAction(Command c, Displayable s)
notifyDestroyed();
I'm trying to get the image logo.png to display at the top but I get the error:
C:\WTK25\apps\AtmosSpec\src\AtmosMIDlet.java:19: cannot find symbol
symbol : constructor ImageItem(javax.microedition.lcdui.Image)
location: class javax.microedition.lcdui.ImageItem
ImageItem logo = new ImageItem(Image.createImage("/logo.png"));
^
1 error
com.sun.kvem.ktools.ExecutionException
Build failed
When I try to build.. Any help would be great.
Ideally the image would be on a seperate screen for a couple of seconds.

New to Java - Wrapper program

Hi there, I'm trying to do something really basic. I want to be able to take data from the user e.g =]'999 and print only the integer so I tried the following...
package assignment2;
import java.util.*;
* @author Aaron
public class WrapperTwo {
* @param args the command line arguments
public static void main(String[] args) {
// TODO code application logic here
Scanner scan = new Scanner(System.in);
String line;
int num;
System.out.println("Enter a number: ");
line = scan.nextLine();
num = Integer.parseInt(line);
System.out.println("" + num);
When I enter just a number e.g 45, it'll print that number. If I enter 45]] or 45p it sends out the following errors:
Exception in thread "main" java.lang.NumberFormatException: For input string: "p99"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Integer.parseInt(Integer.java:447)
at java.lang.Integer.parseInt(Integer.java:497)
at assignment2.WrapperTwo.main(WrapperTwo.java:25)
Java Result: 1
If anyone could tell me where I'm going wrong that would be great. Thanks in advance!

Hi all, thanks for helping!
Before re-checking this post I figured out how to do it. Scan in the string, then take a substring from it before parsing it as an integer as only the first character can be non-numeric. I did it like this:-
package assignment2;
import java.util.*;
* @author Aaron
public class WrapperTwo {
* @param args the command line arguments
public static void main(String[] args) {
// TODO code application logic here
Scanner scan = new Scanner(System.in);
String firstString;
          String firstString2;
int firstNumber;
          System.out.println ("Enter a string: ");
          firstString = scan.nextLine();
          firstString2 = firstString.substring (1);
          firstNumber = Integer.parseInt(firstString2);
          System.out.println ("" + firstNumber);
}

New to Java Wireless Programming - Help needed!

I'm currently finishing my 4 java programmign class in university, and i'm not looking to expand my knowledge in the this language. I would like to learn the how to code for wireless devices. I've already downloaded the Java Wireless Toolkit, but I would really appreciate some direction on what I should read to know where to start with this. Any info that anyone may have is greatly appreciated!
Thanks
Al

Googling J2ME tutorials or MIDP tutorials will give you plenty to read.
but here's a start:
http://www.developer.com/java/j2me/article.php/10934_1561591_1
http://developers.sun.com/techtopics/mobility/midp/samples/index.html#getstart

Understanding java multithread programming

Hi
I am new to java multithreaded programming.
In order to understand more about threading mechanism, I would like to first know more about the processors,operating systems.
Please let me know which book or web site to follow to get a brief but good idea about processors,operating systems that would eventually let me go further with the understanding of multithreading mechanism in java.
Any input is highly appreciated.
Thanks in advance.

Multithread programming is a difficult topic.
If you protect every access to shared memory by using synchronized methods, you are on the safe side.
But things are not so simple in the real world.
Sooner or later, you will face deadlock problems, for instance, and you will learn how to avoid them.
With more experience, you will be tempted to use some "tricks" that you will find on the internet ( double-locking idiom or things like that ), not understanding why it is dangerous and does not work.
If you continue your investigation, you will end up with concepts such as memory barrier, race conditions, spinlocks, mutexes, memory model, processor cache and SMP, instruction reordering, and more.
( google some of these topics how wide the landscape is )
In fact, the more you work with it, the more you will have questions about it, and the more you will want to learn about it.
I also thought that multithreading was easy, three years ago, but it is not true.
Today, I continue to read books about it.
Read a lot ! The topic is wide, but the more you know about it, the best you can use it and be confident with it !
It is worth the effort, as multithreading is here to stay and seems to be everywhere.
Multithreading is difficult to understand fully, but very interesting.
Besides, if you write code for server programs ( serving multiple clients ), you must be aware of it.
Eventually, you will perhaps read this book:
UNIX(R) Systems for Modern Architectures: Symmetric Multiprocessing and Caching for Kernel Programmers
by Curt Schimmel
It is not about java, but if you want to really understand java, you must learn about the underlying layers, and even how a processor works.
As an example of what not to do and that I saw in an introductory book about java, the following code is full of bugs and does not work !
You cannot stop the looping thread B by just setting and testing a global flag like that.
static int stopflag = 0;
Thread A:
public void stop_B_thread()
stopflag = 1;
Thread B:
while (stopflag == 0)
// do some job

Java Concurrent Program issue

Hello,
I am fairly new the Java Concurrent Programs concept. I was just trying a simple Hello World example but I cannot seem to run it from the operating system. Here is my Hello World java program I created using Jdeveloper:
package oracle.apps.fnd.cp.request;
public class Hello implements JavaConcurrentProgram {
public static final String RCS_ID = "$Header$";
public void runProgram(CpContext ctx) {
ctx.getLogFile().writeln("-- Hello World! --", 0);
ctx.getOutFile().writeln("-- Hello World! --");
ctx.getReqCompletion().setCompletion(ReqCompletion.NORMAL, "");
It compiles fine in Jdev generating the class file. Here is what I did :
1) Created directory under $JAVA_TOP as follows :
mkdir $JAVA_TOP/oracle/apps/fnd/cp/sample
2) moved the Hello.java file there under sample directory
3) compiled java file using avac $JAVA_TOP/oracle/apps/fnd/cp/sample/Hello.java ( It compiles fine generating the class file )
4) Now I wanted to test running it : I tried using jre command first as I saw in other posts but this is not working :
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Error :
ksh: jre: not found
Then I tried using the other way I saw on posts which is using the java command :
java -cp $AF_CLASSPATH -Ddbcfile=$FND_TOP/secure/k021kp-6180_r115dev1.dbc -Drequest.outfile=/export/home/sqadri/outfile oracle.apps.fnd.cp.request.Run oracle.apps.fnd.cp.sample.Hello
This gives me the following error :
java.lang.NoClassDefFoundError: oracle/apps/fnd/cp/sample/Hello (wrong name: oracle/apps/fnd/cp/request/Hello)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:141)
at oracle.apps.fnd.cp.request.Run.main(Run.java:157)
Can anyone tell me what I am doing wrong ? I have tried everything even tried ftp the class file from my local but I get the same error. Any help would be appreciated.
Thanks

Ajay,
Yes you are right. I did not register my java program yet in the concurrent programs.
I thought I could test it out from the operating system command line before registering it. But looking at your document you sent me it seems I have to do all the steps i.e. define concurrent program etc before I can test it from the operating system. If that's the case then what's the use of trying to test it via operating system using
java -cp $AF_CLASSPATH -Ddbcfile=$FND_TOP/secure/k021kp-6180_r115dev1.dbc -Drequest.outfile=/export/home/sqadri/outfile oracle.apps.fnd.cp.request.Run oracle.apps.fnd.cp.sample.Hello
Thanks
Syed

How to get Source code of a Schedular Java concurrent program in Payments

Hi Experts,
I am very new to Java Concurrent program.
I need java source code of a schedule java concurrent program.Following are the details of Executable.
Executable :Format Payment Instructions
Short Name :IBY_FD_PAYMENT_FORMAT
Application : Payments
Execution Method :Java Concurrent Program
Execution File Name:FDExtractAndFormatting
Execution File Path : oracle.apps.iby.scheduler
I searched in execution file path,but i am unable to find required java source.
Please someone help regarding this issue..
It's Urgent Issue.
Regards
Amar

Hi Srini,
Thanks for reply...
In the attached template of concurrent program "Format Payment Instructions", i need to add voucher number in the template.
How can i do this?how to decompile the executable?
It is a check printing.
Please give me suggestions..
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Amar

Run Java 3D Program

Hello All,
I am the new in Java 3D Programming. What should i install to run a Java 3D program?
Thanking u,
Ripon

Download and install Java3D API.

Help me with this (I am new to java)

I am completely new to java, and programming all together, for that matter. I am trying to make a java program that will add 2 numbers that I have input (I don't even know what to put so I can input a number, but oh well).
I put together the following program, but I got an error when trying to run it, and don't know what the error means or why.
Program:
class addition
public static void main (String[] args)
int result = 1+2;
System.out.println(result);
Error:
----jGRASP exec: java add
java.lang.NoClassDefFoundError: add
Exception in thread "main"
----jGRASP wedge2: exit code for process is 1.
----jGRASP: operation complete.

Also, what does this mean:
java.lang.NoClassDefFoundErrorTranslated : No Class Definition Found Error. It means you haven't defined a class called "add". You defined a class called "addition". Being this said, I repeat the question, when you are called by another name than yours, do you respond?
I get that all the time when compiling.when compiling or trying to running it? (diferent concepts)
Message was edited by:
Ruly-o_O

New to JAVA, but old school to programming

Objects & Classes & Methods, Oh my!
I'm pretty new to java, but I've been programming in several languages over the years. I thought it was about time to update my skill set, especially with the job market as it is today. I wanted to go JAVA because it's not specific to any environment.
I picked up a begining JAVA book and was a little confused. When I was learning programming a program was called a program. a peice of code in a program called by a statement was called a subroutine (it was performed then control returned to the calling line and continued).
Now I'm trying to make sense of everything I have read so far and trying to relate it back to my old school of thinking. I was hoping it would make it easier to retain and I could expand it as I learn and possibly realize that it IS different. I know it's a new way of thinking, but stay with me for minute.
What I used to call a program is now a CLASS in JAVA (this can be a collection of code or other objects). A sub-routine in a CLASS is a Method. I know that the language part will come as I use it since I understand if's then's and whatever you use to gosub or goto, but I want to make sure I have down the lingo before I go to deep.

I have no idea how you can compare Java to Cobol.
DataFlex? How about that! In about '84 I switched to
DataFlex from dBaseII. In '91 DataFlex changed from
procedural to OOP. It took most of us at least a year
to adjust, and then some to write concrete code. It
was tough. They had bugs and we were limited with DOS.
BUT, it was a great OOP training experience. Anyhow,
needless to day Java is miles ahead on all fronts.Small world. I was stuck in the old DataFlex Ver 2.3 at that time. The company I worked for had the newer OOP package. I did get to work with it some, but not enough to become totally familiar with it. We started to move out of DataFlex towards PowerBuilder towards the end of 1995. I did get some OOP from that experience, but again only enough to learn about global variables, instance variables, and a few other items. I hoping that I will be able to get the solid OOP background that I need from JAVA since I hear through the grapevine that it may be a new tool that we will be looking at to enhance our programming. I was looking at PERL but even the PERL programmers we have agree that JAVA is more scalable.

How can I use a Java program to write an executable Applescript

I'm using a PC with Windows XP. I'm a private developer. I've written a project in Java and wish to deploy it to other people using email. I've written an Install program (the Main-Class) and successfully packed this in a jar file with the project class files and some data files all as described in the deployment trail in the Java Tutorials. A recipient with a Mac with OS X downloads the jar file and runs it to install the project class files and some data files. The install program then writes an Applescript file (Vocab.scpt shown below) on the Desktop to make starting my downloaded program easier but it doesn't seem to work and I think it may be because the script file is not "executable". Could this be the case? If so, how could I change my install program to make the script file executable or alternatively use some other system to start the downloaded program?
Vocab.scpt:-
# Script to start: Vocab Version: 1.0.0
do shell script "cd /Applications/Vocab; Java Vocab"
Many thanks for your interest. Unfortunately I don't have a Mac to experiment with this problem and although I have spent some days on and off trying to find an answer in the mass of information available on Apple's website I can only find small clues here and there to answer my problem (which I would have thought was quite a common one). In Windows a batch file (eg. Vocab.bat) is automatically executable.

I didn't expect you to have your customer run the command. I would expect you to create the executable and install it. However, there wouldn't be any difference in what you are creating and the .jar file. Either way it is a faceless icon. For that matter, it is no different than a batch file on Windows. I'm not sure what they wouldn't understand with, "copy the Vocab.jar file to wherever you want and double-click it to run the program." In addition, you probably ought to point out that Java is not installed on Mac OS X Lion (10.7.x) and when they double-click the jar file (or whatever you send them), the system will ask if they want to install Java.
What you really need to do is package up the app inside a Mac application package and provide the user with the application on a .dmg (disk image). Take a look here: http://developer.apple.com/library/mac/#documentation/Java/Conceptual/Jar_Bundle r/Introduction/Introduction.html#//apple_ref/doc/uid/TP40000884
I also found this which uses ANT to create the bundle: http://informagen.com/JarBundler/

New TO JAVA Programming

Dear Forummembers,
I am student doing postgraduate studies in IT.i have some queries related to one of my programming staff.i am very much new into Java programming and i am finding it a bit difficult to handle this program.The synopsis of the program is given below -
You are required to design and code an object-oriented java program to process bookings for a theatre perfomance.
Your program will read from a data file containing specifications of the performance,including the names of the theatre, the play and its author and the layout of the theatre consisting of the number of seats in each row.
It will then run a menu driven operation to accept theatre bookings or display the current
status of seating in the theatre.
The name of the file containing the details of the performance and the theatre should be
provided at the command line, eg by running the program with the command:
java Booking Theatre.txt
where Theare.txt represents an example of the data file.
A possible data file is:
Opera
U and Me
Jennifer Aniston
5 10 10 11 12 13 14
The data provided is as follows
Line 1
Name of the Theatre
Line 2
Name of the play being performed
Line 3
Name of the author of the play being performed
Line 4
A list of the lengths (number of seats) of each row in the theatre, from front to
back.
The program must start by reading this file, storing all the appropriate parameters and
establishing an object to accept bookings for this performance with all details for the theatre
and performance.
The program should then start a loop in which a menu is presented to the user, eg:
Select from the following:
B - Book seats
T - Display Theatre bookings
Q - Quit from the program
Enter your choice:
And keep performing selected operations until the user�s selects the quit option, when the
program should terminate.
T - Display Theatre bookings
The Display Theatre Bookings option should display a plan of the theatre. Every available
seat should be displayed containing its identification, while reserved seats should contain an
Rows in each theatre are indicated by letters starting from �A� at the front. Seats are
numbered from left to right starting from 1. A typical seat in the theatre might be designated
D12, representing seat 12 in row D.
B - Book seats
The booking of seats is to offer a number of different options.
First the customer must be asked how many adjacent seats are
required. Then start a loop offering a further menu of choices:
Enter one of the following:
The first seat of a selected series, eg D12
A preferred row letter, eg F
A ? to have the first available sequence selected for you
A # to see a display of all available seats
A 0 to cancel your attempt to book seats
Enter your selection:
1. If the user enters a seat indentifier such B6, The program should attempt to
reserve the required seats starting from that seat. For example if 4 seats are
required from B6, seats B6, B7, B8 and B9 should be reserved for the customer,
with a message confirming the reservation and specifying the seats reserved..
Before this booking can take place, some testing is required. Firstly, the row
letter must be a valid row. Then the seat number must be within the seats in the
row and such that the 4 seats would not go beyond the end of the row. The
program must then check that none of the required seats is already reserved.
If the seats are invalid or already reserved, no reservation should be made and the
booking menu should be repeated to give the customer a further chance to book
seats.
If the reservation is successful, return to the main menu.
2. The user can also simply enter a row letter, eg B.IN this case, the program should
first check that the letter is a valid row and then offer the user in turn each
adjacent block of the required size in the specified row and for each ask whether
the customer wants to take them. Using the partly booked theatre layout above, if
the customer wanted 2 seats from row B, the customer should be offered first:
Seats B5 to B6
then if the customer does not want them:
Seats B10 to B11
and finally
Seats B11 to B12
If the customer selects a block of seats, then return to the main menu. If none are
selected, or there is no block of the required size available in the row, then report
that no further blocks of the required size are available in the row and repeat the
booking menu.
3. If the user enters a ? the program should offer the customer every block of seats
of the required size in the whole theatre. This process should start from the first
row and proceed back a row at a time. For example, again using the partially
booked theatre shown above, if the user requested 9 seats, the program should
offer in turn:
Seats A1 to A9
Seats C1 to C9
Seats C2 to C10
Seats E3 to E11
Seats E4 to E12
If the customer selects a block of seats, then return to the main menu. If none are
selected, or there is no block of the required size available in the whole theatre,
then report that no further blocks of the required size are available and repeat the
booking menu.
4. If the user enters a # the program should display the current status of the seating
in the theatre, exactly the same as for the T option from the main menu and then
repeat the booking menu.
5. If the user enters a 0 (zero), the program should exit from the booking menu back
to the main menu. If for example the user wanted 9 seats and no block of 9 was
left in the theatre, he would need to make two separate smaller bookings.
The program should perform limited data validation in the booking process. If a single
character other than 0, ? and # is entered, it should be treated as a row letter and then tested
for falling within the range of valid rows, eg A to H in the example above. Any invalid row
letters should be rejected.
If more than one character is entered, the first character should be tested as a valid row letter,
and the numeric part should be tested for falling within the given row. You are NOT
required to test for valid numeric input as this would require the use of Exception handling.
You are provided with a class file:
Pad.java
containing methods that can be used for neat alignment of the seat identifiers in the theatre
plan.
File Processing
The file to be read must be opened within the program and if the named file does not exist, a
FileNotFoundException will be generated. It is desirable that this Exception be caught and
a corrected file name should be asked for.
This is not required for this assignment, as Exception handling has not been covered in this
Unit. It will be acceptable if the method simply throws IOException in its heading.
The only checking that is required is to make sure that the user does supply a file on the
command line, containing details of the performance. This can be tested for by checking the
length of the parameter array args. The array length should be 1. If not, display an error
message telling the user the correct way to run the program and then terminate the program
System.exit(0);
The file should be closed after reading is completed.
Program Requirements
You are expected to create at least three classes in developing a solution to this problem.
There should be an outer driving class, a class to represent the theatre performance and its
bookings and a class to represent a single row within the theatre.
You will also need to use arrays at two levels. You will need an array of Rows in the Theatre
class.
Each Row object will need an array of seats to keep track of which seats have been reserved.
Your outer driving class should be called BookingOffice and should be submitted in a file named BookingOffice.java
Your second, third and any additional classes, should be submitted in separate files, each
class in a .java file named with the same name as the class
I am also very sorry to give such a long description.but i mainly want to know how to approach for this program.
also how to designate each row about it's column while it is being read from the text file, how to store it, how to denote first row as row A(second row as row B and so on) and WHICH CLASS WILL PERFORM WHICH OPERATIONS.
pls do give a rough guideline about designing each class and it's reponsibilty.
thanking u and looking forward for your help,
sincerely
RK

yes i do know that........but can u ppl pls mention
atleast what classes shud i consider and what will be
the functions of each class?No, sorry. Maybe somebody else will, but in general, this is not a good question for this forum. It's too broad, and the question you're asking is an overall problem solving approach that you should be familiar with at this point.
These forums are best suited to more specific questions. "How do I approach this homework?" is not something that most people are willing or able to answer in a forum like this.

New to Java and need help with this program..please!

I'd really appreciate any helpful comments about this program assignment that I have to turn in a week from Friday. I'm taking a class one night a week and completely new to Java. I'd ask my professor for help, but we can't call him during the week and he never answers e-mails. He didn't tell us how to call from other classes yet, and I just can't get the darn thing to do what I want it to do!
The assignment requirements are:
1. Change a card game application that draws two cards
and the higher card wins, to a Blackjack application
2. Include a new class called Hand
3. The Hand class should record the number of draws
4. The application should prompt for a number of draws
5. The game is played against the Dealer
6. The dealer always draws a card if the dealer's hand total is <= 17
7. Prompt the player after each hand if he wants to quit
8. Display the total games won by the dealer and total and the total games wond by the player after each hand
9. Display all of the dealer's and player's cards at the
end of each hand
10. Player has the option of drawing an additional card after the first two cards
11. The Ace can have a value of 11 or 1
(Even though it's not called for in the requirements, I would like to be able to let the Ace have a value of 1 or an 11)
The following is my code with some comments about a few things that are driving me nuts:
import java.util.*;
import javax.swing.*;
import java.text.*;
public class CardDeck
public CardDeck()
deck = new Card[52];
fill();
shuffle();
public void fill()
int i;
int j;
for (i = 1; i <= 13; i++)
for (j = 1; j <= 4; j++)
deck[4 * (i - 1) + j - 1] = new Card(i, j);
cards = 52;
public void shuffle()
int next;
for (next = 0; next < cards - 1; next++)
int rand = (int)(Math.random()*(next+1));
Card temp = deck[next];
deck[next] = deck[rand];
deck[rand] = temp;
public final Card draw()
if (cards == 0)
return null;
cards--;
return deck[cards];
public int changeValue()
int val = 0;
boolean ace = false;
int cds;
for (int i = 0; i < cards; i++)
if (cardValue > 10)
cardValue = 10;
if (cardValue ==1)     {
ace = true;
val = val + cardValue;
if ( ace = true && val + 10 <= 21 )
val = val + 10;
return val;
public static void main(String[] args)
CardDeck d = new CardDeck();
int x = 3;
int i;
int wins = 1;
int playerTotal = 1;
do {
Card dealer = (d.draw());
/**I've tried everything I can think of to call the ChangeValue() method after I draw the card, but nothing is working for me.**/
System.out.println("Dealer draws: " + dealer);
do {
dealer = (d.draw());
System.out.println(" " + dealer);
}while (dealer.rank() <= 17);
Card mine = d.draw();
System.out.println("\t\t\t\t Player draws: "
+ mine);
mine = d.draw();
System.out.println("\t\t\t\t\t\t" + mine);
do{
String input = JOptionPane.showInputDialog
("Would you like a card? ");
if(input.equalsIgnoreCase("yes"))
     mine = d.draw();
System.out.println("\t\t\t\t\t\t" + mine);
     playerTotal++;
     else if(input.equalsIgnoreCase("no"))
System.out.println("\t\t\t\t Player stands");
     else
System.out.println("\t\tInvalid input.
Please try again.");
I don't know how to go about making and calling a method or class that will combine the total cards delt to the player and the total cards delt to the dealer. The rank() method only seems to give me the last cards drawn to compare with when I try to do the tests.**/
if ((dealer.rank() > mine.rank())
&& (dealer.rank() <= 21)
|| (mine.rank() > 21)
&& (dealer.rank() < 22)
|| ((dealer.rank() == 21)
&& (mine.rank() == 21))
|| ((mine.rank() > 21)
&& (dealer.rank() <= 21)))
System.out.println("Dealer wins");
wins++;
     else
System.out.println("I win!");
break;
} while (playerTotal <= 1);
String stop = JOptionPane.showInputDialog
("Would you like to play again? ");
if (stop.equalsIgnoreCase("no"))
break;
if (rounds == 5)
System.out.println("Player wins " +
(CardDeck.rounds - wins) + "rounds");
} while (rounds <= 5);
private Card[] deck;
private int cards;
public static int rounds = 1;
public int cardValue;
/**When I try to compile this nested class, I get an error message saying I need a brace here and at the end of the program. I don't know if any of this code would work because I've tried adding braces and still can't compile it.**/
class Hand()
static int r = 1;
public Hand() { CardDeck.rounds = r; }
public int getRounds() { return r++; }
final class Card
public static final int ACE = 1;
public static final int JACK = 11;
public static final int QUEEN = 12;
public static final int KING = 13;
public static final int CLUBS = 1;
public static final int DIAMONDS = 2;
public static final int HEARTS = 3;
public static final int SPADES = 4;
public Card(int v, int s)
value = v;
suit = s;
public int getValue() { return value; }
public int getSuit() { return suit; }
public int rank()
if (value == 1)
return 4 * 13 + suit;
else
return 4 * (value - 1) + suit;
/**This works, but I'm confused. How is this method called? Does it call itself?**/
public String toString()
String v;
String s;
if (value == ACE)
v = "Ace";
else if (value == JACK)
v = "Jack";
else if (value == QUEEN)
v = "Queen";
else if (value == KING)
v = "King";
else
v = String.valueOf(value);
if (suit == DIAMONDS)
s = "Diamonds";
else if (suit == HEARTS)
s = "Hearts";
else if (suit == SPADES)
s = "Spades";
else
s = "Clubs";
return v + " of " + s;
private int value; //Value is an integer, so how can a
private int suit; //string be assigned to an integer?
}

Thank you so much for offering to help me with this Jamie! When I tried to call change value using:
Card dealer = (d.changeValue());
I get an error message saying:
Incompatible types found: int
required: Card
I had my weekly class last night and the professor cleared up a few things for me, but I've not had time to make all of the necessary changes. I did find out how toString worked, so that's one question out of the way, and he gave us a lot of information for adding another class to generate random numbers.
Again, thank you so much. I really want to learn this but I'm feeling so stupid right now. Any help you can give me about the above error message would be appreciated.

New to java - glitch in my program/game? should be a simple fix :)

hey everyone, I'm a student who's new to java programming :) It's is also the first programming language that I'm learning. I know the basics, but nothing very complicated.
I'm making a pong-like game, in an applet.
As I was making the paddle and using a mouselistener to make it move vertically, I came across this problem, the paddle will move vertically with the mouse's position, but one end of my paddle will grow abnormally (I want it to stay the same size as it moves up and down)
Here's my code: (I'm not using most of the mouselistener and keylistener classes yet, so you can ignore them. I'm guessing the problem is probably in one of the last classes, at the bottom)
ypaddle is the variable used for getting the co-ordinates of the mouse and transferring them to the paddle itself
// The "Ping" class.
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
*Ping
public class Ping extends Applet
    implements KeyListener, MouseListener, MouseMotionListener
    int width, height, x, ypaddle;
    Graphics g;
    char move;
     *Initializes variables
    public void init ()
        resize (700, 500);
        setBackground (Color.white);
        addKeyListener (this);
        addMouseListener (this);
        addMouseMotionListener(this);
    public void keyPressed (KeyEvent e)
    public void keyReleased (KeyEvent e)
    public void keyTyped (KeyEvent e)
    public void mouseEntered (MouseEvent e)
    public void mouseExited (MouseEvent e)
    public void mousePressed (MouseEvent e)
    public void mouseReleased (MouseEvent e)
    public void mouseClicked (MouseEvent e)
    public void mouseMoved (MouseEvent e)
        ypaddle = e.getY ();
        repaint();
    public void mouseDragged (MouseEvent e)
    public void paint (Graphics g)
        paddle (g, ypaddle);
     * Creates the paddle for hitting the ball
     *@param    y   value used to move the paddle vertically
    public void paddle (Graphics g, int y)
        g.fillRect (10, 10+y, 15, 60+y);
} // Ping classI'm totally stumped, I've tried for 2 hours to find the problem, and I have a feeling it's something very simple that I'm passing over...
If you have any questions about the variables or other things, please ask!
And one last little quick question, is there a way I can restrict the movement of the paddle between two Y values? (i.e not higher than y=10 or lower than y=100)
Thanks in advance :)

soundweave wrote:
I'm not exactly sure how to find out, Eh?
You wrote this code:
g.fillRect (10, 10+y, 15, 60+y);Do you understand what fillRect does? If I call fillRect(10, 20, 30, 40) where will that rectangle be drawn? If you don't know how to answer that, I don't see how you could have written that line of code.
but here's some pictures of what happens ( I put in 0 and 80 as the y values in each picture, and left the code window open so you can see )I don't need to see them.
Y at 0: [http://i731.photobucket.com/albums/ww314/len56/Untitled.jpg?t=1263077701|http://i731.photobucket.com/albums/ww314/len56/Untitled.jpg?t=1263077701]
Y at 80: [http://i731.photobucket.com/albums/ww314/len56/Untitled2.jpg?t=1263077625|http://i731.photobucket.com/albums/ww314/len56/Untitled2.jpg?t=1263077625]
So, given that the first one comes from fillRect(10, 10, 15, 60), (you get where that comes from I hope) and the second comes from fillRect(10, 90, 15, 150) (that too), does that not suggest that something is wrong with the numbers you're passing to fillRect? And since you have read the docs for fillRect and know what it does and what each of its parameters represents (right?), does it not suggest exactly what is wrong with those numbers?

New to Java...Tough program to write I think...

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