Abstract class, a question

i have an abstract class called shape with default constructor (double y1, double y2);
with an abstract method area.
now i have a circle class which extends it, but i want its constructor to have ONE radius (as its pi radius*radius)
at the moment this is how my circle looks like, and as you can see that there is really no need for second radius how can i modify circle class without modifying shape class?
class circle extends Shape{
circle(double radius, double radius1) {
super(radius, radius);
double area() {
return (3.14*x1*x1);
}

the answer from the test class in above case will be
0!Yes, because 3.14 * 0 * 0 is 0.
but if i change the x3 above to x1, it would work, You honestly don't see why? It's staring you right in the face. What does area() use? How does that field get set?
the
reason i decided to use x3 is so that ppl dont get
confuse! Here's what's confusing:
* field names x1, x2, x3. What do those mean? They sound like 3 x coordinates.
* two fields that are used by certain subclasses, but not others, and a third field that's used only by the subclasses that don't use the first two.
* that third field meaning "the single value that applies to what both of the other two fields mean" instead of just setting both fields to the same value.
* having any of those fields in there at all in the first place when they're not used by the abstract class and not used consistently by subclasses.
but shouldnt it work because i have done the
same thing i did to x1 and x2??

Similar Messages

EJB question: How to use abstract class in writing a session bean?

I had written an abstract class which implements the session bean as follow:
public abstract class LoggingSessionBean implements SessionBean {
protected SessionContext ctx;
protected abstract Object editRecord(Object obj) throws Exception;
public LoggingSessionBean()
super();
private final String getBeforeUpdateImage(Object obj) throws Exception {
// implement the details of extracting the backup image ...
public void setSessionContext(SessionContext ctx)
this.ctx = ctx;
private final void writeThisImageToDatabase(String aStr) {
// connect to database to write the record ...
public final Object update(final Object obj) {
try {
final String aStr = getBeforeUpdateImage(obj);
writeThisImageToDatabase(aStr);
editRecord(obj);
} catch (Exception e) {
ctx.setRollbackOnly();
This abstract class is to write the backup image to the database so that other session beans extending it only need to implement the details in editRecord(Object Obj) and they do not need to take care of the operation of making the backup image.
However, some several questions for me are:
1. If I write a class ScheduleSessionBean extending the above abstract class and the according 2 interfaces ScheduleSession and ScheduleSessionHome for this session bean (void update(Object obj); defined in ScheduleSession), do I still need to write the interfaces for LoggingSession and LoggingSessionHome?
2. If I wrote the interface LoggingSession extending EJBObject where it defined the abstract methods "void update(Object obj);" and "void setSessionContext(SessionContext ctx);", that this meant I needed to write the ScheduleSession to implement the Logging Session?
3. I used OC4J 9.0.4. How can I define the ejb-jar.xml in this case?

Hi Maggie,
1. do I still need to write
the interfaces for LoggingSession and
LoggingSessionHome?"LoggingSessionBean" can't be a session bean, because it's an abstract class. Therefore there's no point in thinking about the 'home' and 'remote' interfaces.
2. this
meant I needed to write the ScheduleSession to
implement the Logging Session?Again, not really a question worth considering, since "LoggingSessionBean" can't be an EJB.
3. I used OC4J 9.0.4. How can I define the
ejb-jar.xml in this case?Same as you define it for any version of OC4J and for any EJB container, for that matter, since the "ejb-jar.xml" file is defined by the EJB specification.
Let me suggest that you create a "Logging" class as a regular java class, and give your "ScheduleSessionBean" a member that is an instance of the "Logging" class.
Alternatively, the "ScheduleSessionBean" can extend the "Logging" class and implement the "SessionBean" interface.
Good Luck,
Avi.

A question about Abstract Classes

Hello
Can someone please help me with the following question.
Going through Brian's tutorials he defines in one of his exercises an 'abstract' class as follows
<ClassType ID="MyMP.MyComputerRoleBase" Base="Windows!Microsoft.Windows.ComputerRole" Accessibility="Internal" Abstract="true" Hosted="true" Singleton="false">
Now I am new to authoring but get the general concepts, and on the surface of it, it appears odd to have an 'abstract' class that is also 'hosted' I understand and abstract class to be a template with one or more properties defined which is then used
as the base class for one or more concrete classes. Therefore you do not have to keep defining the properties on these concrete classes over and over as they inherit the properties from their parent abstract class, is this correct so far?
if the above is correct then it seems odd that the abstract class would be hosted, unless (and this is the only way it makes sense to me) that ultimately (apart from singleton classes) any class that is going to end up being discovered and
thereby an instance of said class instigated in the database must ultimately be hosted somewhere, is that correct?
in other words if you has an abstract class, which acts as the base class for one or more concrete classes (by which I mean ones for which you are going to create lets say WMI discoveries ), if this parent abstract class is not ultimately
hosted to a concrete class of its own then these child concrete classes (once discovered) will never actually create instances in the database.
Is that how it is?
Any advise most welcome, thanks
AAnotherUser__
AAnotherUser__

Hi,
Hosting is the only relationship type that doesn't require you to discover it with a discovery rule. OpsMgr will create a relationship instance automatically for you using a 'hosted' properties 'chain' in a class\model definition. In an abstract class definition
you need to have this property set to 'true' or you will 'brake' a hosting 'chain'.
http://OpsMgr.ru/

Weird Abstract Class Question

First off, I hope I'm posting in the correct section of the forum, apologies if I'm not.
I have a bit a of a weird query more so than a question.
I have recently been given the challenge of developing a mobile application. So as one does when one gets a job, they sit down and have a think about how to best use Java inheritance to make my their design nice and neat.
So anyway to do some of the GPS stuff for my app I am using the JSF-179, an API specification for location info. So this JSF API is implemented by a number of providers, nokia, samsung, sony ericsson, etc..
So as all implementations stick to the API, the code should remain the same for each platform, the only change will be where the code is imported from.
So for example each class will have:
import com.nokia.jsf-179
import com.sony.jsf-179
import com.samsung.jsf-179And this import info will be the only code that will change.
I had a number of ideas:
1 - Create an Interface with methods each concrete class can implement, but with this approach a code re-write is required. Also each sub class will conform to the java is-a rule so it really should extend an abstract class as opposed to implement an Interface.
2 - Extend Abstract class, we still have the code re-write issue.
So how then do I keep the code the same but only change the import info all nice and neat like? Is there some kind of abstract marker for imports?

kajbj wrote:
@Op. I don't know if you question is more of a design question, or if you have a question that is related to Java ME, or development on mobile phones. I'm however moving this thread from the Generics forum (since the question isn't related to Generics).given that [Joahim's answer|http://forums.sun.com/thread.jspa?messageID=10806927#10806927] satisfied OP, this topic better matches Java ME than design. Suggest to move it to CLDC and MIDP forum for closer toipic alignment

Question about Abstract Classes and Class Inheritance

The semester is winding down, and the assignments are getting more complicated....
Prof has given us a project involving both an interface and an abstract class. There's a class Person, then an abstract class Employee that extends Person, and two types of Employees (Hourly and Salaried) that extend Employee. The finished assignment is a type of payroll program that's supposed to be able to store both types of Employees and related info (name, salary, etc). One thing the prof suggested was to store both HourlyEmployees and SalariedEmployees in an array of Employees. But you can't instantiate an array of Employees directly, of course, since it's an abstract class.
So is it possible to create an array of Persons, cast either HourlyEmployees or SalariedEmployees into Employee objects, and then store the Employee objects in the Person array? And if I do that, can I still use methods particular to the SalariedEmployees and/or HourlyEmployees once they are in the Person array? Or can I store SalariedEmployee and HourlyEmployee directly in an array of Persons, without having to cast them into anything else? (In that case, I'm not sure what the point of having the abstract Employee class is, though). Do they become just generic "Persons" if I do this?
Thanks for any help!

But you
can't instantiate an array of Employees directly, of
course, since it's an abstract class.Sure you can. You just can't instantiate Employee (the abstact class itself, as opposed to its subclasses) objects.
Employee[] employees = new Employee[20];
employees[0] = new HourlyEmployee();That should work.
So is it possible to create an array of Persons, cast
either HourlyEmployees or SalariedEmployees into
Employee objects, and then store the Employee objects
in the Person array?You could do that as well, but you shouldn't need to cast it.
Given the type hierarchy you describe, an HourlyEmployee is a Person, so you should be able to assign an HourlyEmployee directly to a Person-valued variable.
And if I do that, can I still use
methods particular to the SalariedEmployees and/or
HourlyEmployees once they are in the Person array?No. If the method doesn't exist in Person, then you can't call it on a Person variable, even if the method does exist in the class implementing Person.
But if the method exists in Person, but is implemented and possibly overridden in HourlyEmployee, you can still invoke it, by just invoking the Person method.
public interface Person {
public void feed();
public abstract class Employee implements Person {
public abstract void hire();
public class HourlyEmployee extends Employee {
// then:
Person persons = new Person[20];
// add HourlyEmployees or SalariedEmployees to persons array...
persons[0].feed(); // OK!
persons[0].hire(); // NOT OK!

Question about abstract classes

abstract class Animal
abstract boolean alive();
class Dog extends Animal
public int age;
class Test
public void main(String args[])
Animal a = new Dog();
a.age = 2; // <== Doesn't work, why?
}

abstract class Animal
abstract boolean alive();
class Dog extends Animal
public int age;
class Test
public void main(String args[])
Animal a = new Dog();
a.age = 2; // <== Doesn't work, why?
}because a is an "Animal" and you didn't specify that all "Animal"s have an "age" - only that "Dog"s do. So of course you would have had to do:
Dog a = new Dog();
a.age = 2;
(It still wouldn't have compiled anyway however, because you didn't implement the "alive" method in Dog)

Question about abstract classes and instances

I have just read about abstract classes and have learned that they cannot be instantiated.
I am doing some exercises and have done a class named "Person" and an abstract class named "Animal".
I want to create a method in "Person" that makes it possible to set more animals to Person objects.
So I wrote this method in class Person and compiled it and did not get any errors, but will this work later when I run the main-method?
public void addAnimal(Animal newAnimal)
animal.add(newAnimal);
}Is newAnimal not an instance?

Roxxor wrote:
Ok, but why is it necessary with constructors in abstract classes if we don�t use them (because what I have understand, constructors are used to create objects)?Constructors don't create objects. The new operator creates objects. An object's c'tor is invoked after the object has already been created. The c'tors job is to initialize the newly-created object to a valid state. Whenever a child object is created, the parent's c'tor is run before the child's c'tor, so that by the time we're inside the child's c'tor, setting up the child's state, we know that the parent (or rather the "parent part" of the object we're initializing) is in a valid state.
Constructor rules:
1) Every class has at least one ctor.
1.1) If you do not define an explicit constructor for your class, the compiler provides a implicit constructor that takes no args and simply calls super().
1.2) If you do define one or more explicit constructors, regardless of whether they take args, then the compiler no longer provides the implicit no-arg ctor. In this case, you must explicitly define a public MyClass() {...} if you want one.
1.3) Constructors are not inherited.
2) The first statement in the body of any ctor is either a call to a superclass ctor super(...) or a call to another ctor of this class this(...) 2.1) If you do not explicitly put a call to super(...) or this(...) as the first statement in a ctor that you define, then the compiler implicitly inserts a call to super's no-arg ctor super() as the first call. The implicitly called ctor is always super's no-arg ctor, regardless of whether the currently running ctor takes args.
2.2) There is always exactly one call to either super(...) or this(...) in each constructor, and it is always the first call. You can't put in more than one, and if you put one in, the compiler's implicitly provided one is removed.

Question on abstract classes

I just need to make sure that I have a concept right. I know that interface declarations can have fields, but they must be initialized and constant. In an abstract class though, can they also have fields, since it can acept both abstract and concrete methods? If so, do they have the same requirements as an interface? Thanks!

Yes, abstract classes can have fields.
No, it does not have the same requirements as an interface.
It is a class, and so can do everything a concrete class can do, except be instantiated.
It depends on the visibility of the field you define.
Defining a field private means that it can't even be used by its subclasses. Sometimes you might want that, sometimes not.

Generics/Abstract class question

I'm not sure exactly what my problem is here. I am creating an abstract class for a number of other data types that I am creating. The purpose of this class is to track changes so that the GUI can prompt the user to save changes if they try to exit without saving. I want to do this by storing a reference of the original object and then making changes on a new object. I am running into problems though. Right now I am trying to define the clone method in that class and am getting an error.
public abstract class ChangeableDataType<T extends ChangeableDataType>{
    protected T old;
    public Object clone(){
        T t = new T(); // Error occurs here
        //Stuff
    }The error I get is unexpected type on the line where I try to call a new T(). Is this not something that I can do? I have tried to put any code in that I thought might have the problem.

No, that isn't something you can do. I'm sure it's discussed in more (and better) detail in [the Generics FAQ|http://www.angelikalanger.com/GenericsFAQ/JavaGenericsFAQ.html] though.

Question about Classes, Abstract Classes and Interfaces.

I have been experimenting with Classes, Abstract Classes and Interfaces and wonder if anyone can explain this to me.
I was looking for a way to assign a value to a variable and then keep it fixed for the session and have devised this.
First I create an abstract class like this:
public abstract class DatabaseConnection {
private static String ServerName = null;
public static void setServerName(String serverName) {
          ServerName = serverName;
     public static String getServerName() {
          return ServerName;
}and then I created an interface
public interface DatabaseAccess {
     String servername = DatabaseConnection.getServerName();
}And finally the class itself with some test lines in it so I could see what was going on:
public class CreateDatabase extends DatabaseConnection implements DatabaseAccess {
     public static void main (String args[]){
          new CreateDatabase();
     public CreateDatabase(){
          setServerName("Server Name 1");
          System.out.println ("Before update ");
          System.out.println ("ServerName from Interface           = " + servername);
          System.out.println ("ServerName from Abstract Class = " + getServerName());
          System.out.println ("After update ");
          setServerName("Server Name 2");
          System.out.println ("ServerName from Interface           = " + servername);
          System.out.println ("ServerName from Abstract Class = " + getServerName());
          System.out.println ("==========================");
}The output I get from the above is:
Before update
ServerName from Interface           = Server Name 1
ServerName from Abstract Class = Server Name 1
After update
ServerName from Interface           = Server Name 1
ServerName from Abstract Class = Server Name 2
==========================I also tried this in another class which calls the above class to see if I get the same effect
public class CheckDatabaseAccess {
     public static void main (String args[]){
          new CreateDatabase();
          CreateDatabase.setServerName("Server 3");
          System.out.println("CreateDatabase "+CreateDatabase.servername);
          CreateDatabase.setServerName("Server 4");
          System.out.println("CreateDatabase "+CreateDatabase.servername);
          CreateDatabase.setServerName("Server 5");
          System.out.println("CreateDatabase "+CreateDatabase.servername);
}The output of which is this:
Before update
ServerName from Interface           = Server Name 1
ServerName from Abstract Class = Server Name 1
After update
ServerName from Interface           = Server Name 1
ServerName from Abstract Class = Server Name 2
==========================
CreateDatabase Server Name 1
CreateDatabase Server Name 1
CreateDatabase Server Name 1Can anyone explain why I appear to only be able to change or set the ServerName only the once?
Is this the correct way to do it? If it is it's exactly what I am looking for, a way to set the value of variable once in a session and then prevent it being changed.
Or is there a better way of doing this.
What I want to use this for is for example, storing the accesses to a database on a server. I won't know what server the database will be stored on nor what the database is called so I create an INI file which stores this information in encrypted format, which is set by the database administrator. It occurs to me I can use this method to then retrieve that data once and once only from the INI file and use that throughout the life of the session to access the database.
Any help appreciated
Regards
John

Not gonna read all of it, but this jumps out:
public abstract class DatabaseConnection {
private static String ServerName = null;
public interface DatabaseAccess {
     String servername = DatabaseConnection.getServerName();
}You have two completely separate variables (with two different names, for that matter, since you were inconsistent in your capitalization, but it wouldn't make a difference if they did have the same name with the same case). And the one in the interface is implicitly public, static, and final.
Anytime you refer to "servername" through a reference of type DatabaseAccess, it refers to the one declared in the interface.
Anytime you refer to "ServerName" inside the DatabaseConnection class, it refers to the one declared in that class.

A Singleton variable in an Abstract Class

Hello there people
I have a quick question. I have made an abstract class in which I want to put an identifier (ID) int to be incremented whenever I make any of the concrete class instances that extend this abstract class.
whould that declairation be as follows?:
public static int IDAdditionally, I have a quick question about abstract constructors. If constructors are defined in the concrete classes, are their declairations needed in the abstract class?
and finally, if I wanted to use the int ID (as mentioned above) then would I have to use constructor from the abstract class?
thanks in advance for the help

I think the OP would want a constructor in the abstract class to update that variable. Otherwise, he'd have to remember to update it in the constructor for all concrete classes. But, you don't declare constructors for the concrete class in the abstract class. You only declare constructors for the abstract class in the abstract class.

Beginner CORBA idl struct said to be abstract class

How do I instantiate a class declared in my .idl file for use by the methods implementing the interface?
I want to return an array of Record objects in my CORBA implentation, and my .idl file has: struct Record
    long recordNumber;
    string firstName;
    string lastName;
    string streetAddress;
    string city;
    string country;
    string phone;
    string eMail;
    string fax;
     typedef sequence <Record> recordSet;
interface AddRecord
    void setUser(in string user);
    string getUser();
        recordSet getRecords();
// plus more stuffWhen my implementing class in the server tries to define the getRecords() method like so: public Record[] getRecords()
    Record r = null;
    Record[] allRecs;
    int index = 0;
    String selectAll = "SELECT * FROM Record ORDER BY Record_number";
    try
      Statement s = connection.createStatement();
      ResultSet recs = s.executeQuery(selectAll);
      while(recs.next())
        index++;
      allRecs = new Record[index];
//plus more stuffthe compiler complains
C:\My Documents\Java\CIS 290\hw5\RecordObj.java:178: Record is abstract; cannot be instantiated
r = new Record();
I went into the Record.java that the idlj compiler generated, and it is a final, non-abstract class. What incantation do I need here?

Whoops; solved that one; the real question is this: My .idl file declares some methods that I want to call in my implementation, but the .java class generated by the idlj compiler doesn't show the methods. Here's the full idl:module hw5Corba
typedef sequence <string> columns;
struct Record
    long recordNumber;
    string firstName;
    string lastName;
    string streetAddress;
    string city;
    string country;
    string phone;
    string eMail;
    string fax;
   typedef sequence <Record> recordSet;
interface AddRecord
   void setUser(in string user);
    string getUser();
   recordSet getRecords();
    columns getColumnNames(in string user);
    void newRecord(in Record r);
    void deleteRecord(in long num);
    void updateRecord(in Record r);
    void setRecordNumber(in long num);
    long getRecordNumber();
    void setFirstName(in string first);
    string getFirstName();
    void setLastName(in string last);
    string getLastName();
    void setStreetAddr(in string add);
    string getStreetAddr();
    void setCity(in string city);
    string getCity();
    void setCountry(in string country);
    string getCountry();
    void setEmail(in string email);
    string getEmail();
    void setPhone(in string phone);
    string getPhone();
    void setFax(in string fax);
    string getFax();
};Here's the method I expect to be able to implement: public Record[] getRecords()
    Record r = null;
    Record[] allRecs;
    int index = 0;
    String selectAll = "SELECT * FROM Record ORDER BY Record_number";
    try
      Statement s = connection.createStatement();
      ResultSet recs = s.executeQuery(selectAll);
      while(recs.next())
        index++;
      allRecs = new Record[index];
      //cycle through records again, adding each
      //to the array
      index = 0;
      recs = s.executeQuery(selectAll);
      while(recs.next())
        r = new Record();
        r.setRecordNumber(recs.getInt(1));
        r.setFirstName(recs.getString(2));
        r.setLastName(recs.getString(3));
        r.setStreetAddr(recs.getString(4));
        r.setCity(recs.getString(5));
        r.setCountry(recs.getString(6));
        r.setEmail(recs.getString(7));
        r.setPhone(recs.getString(8));
        r.setFax(recs.getString(9));
        allRecs[index] = r;
      catch (SQLException ex)
        exceptionCode(ex);
    return allRecs;
}The compiler error lists the 9 sub-methods as "can't resolve symbol", because as the Record.java file generated by the idlj shows, the methods aren't there:package hw5Corba;
* hw5Corba/Record.java
* Generated by the IDL-to-Java compiler (portable), version "3.0"
* from Record.idl
* Tuesday, November 20, 2001 10:08:15 PM CST
public final class Record implements org.omg.CORBA.portable.IDLEntity
public int recordNumber = (int)0;
public String firstName = null;
public String lastName = null;
public String streetAddress = null;
public String city = null;
public String country = null;
public String phone = null;
public String eMail = null;
public String fax = null;
public Record ()
} // ctor
public Record (int _recordNumber,
String _firstName, String _lastName,
String _streetAddress, String _city,
String _country, String _phone,
String _eMail, String _fax)
    recordNumber = _recordNumber;
    firstName = _firstName;
    lastName = _lastName;
    streetAddress = _streetAddress;
    city = _city;
    country = _country;
    phone = _phone;
    eMail = _eMail;
    fax = _fax;
} // ctor
} // class Record What do I need to do to implement these methods declared in the .idl file?

Abstract classes and static methods

I have an abstract report class AbstractReportClass which I am extending in multiple report classes (one for each report, say ReportA, ReportB, ...). Each report class has its own static column definitions, title, etc., which I have to access through a static method getDataMeta() in a web application. Each report has the same exact code in getDataMeta, and no report may exist without these fields. My intuition tells me that AbstractReportClass should contain the code for getDataMeta, but I know that you can't mix abstract and static keywords.
Am I missing a simple solution to unify the getDataMeta code in the abstract base class? or do I really need to have a static function getDataMeta with the same code in each of the base classes?
My apologies if this has been discussed many times before.
Thanks,
-Andrew

I'm not trying to be "right"; rather I just asked a question about whether I can do something that seems intuitive. Perhaps you might write code in a different way than I would or perhaps I wasn't clear about every little detail about my code? Do you regularly belittle people who ask questions here?
I have a loadFromDB() member function in AbstractReport for which all sub classes have an overloaded version. All reports I'm displaying have 4 common fields (a database id and a name and a monetary value, for example), but then each other report has additional fields it loads from the database. Inside ReportX classes' loadFromDB(), I call the superclass loadFromDB() function and augment values to get a completely loaded object. In fact, the loadedData member object resides in AbstractReport.
I can't use a report unless it has these common features. Every report is an AbstractReport. There is common functionality built on top of common objects. Isn't this the point of inheritance? I'm essentially saying that abstract class Shape has a getArea function and then I'm defining multiple types of Shapes (e.g. Rectangle and Circle) to work with...

Abstract class extending a nonabstract

i want to know what are the effects , advantages and cases were we want to use this cinda achitecture.
I have a class(NA) which is NonAbstract, There is a Abstract class(A) which extends a NA. Doing so is legally right, but what are the advantages of doing that are there any situations were we will be using this technique.
TIA
Zoha.

Every abstract class extends a non-abstract class already: Object is non-abstract, and since all abstract classes directly or indirectly extend Object... see?
So if you can see the reason for abstract classes at all, then you don't need to ask this question.

Abstract classes and methods with dollar.decimal not displaying correctly

Hi, I'm working on a homework assignment and need a little help. I have two classes, 1 abstract class, 1 extends class and 1 program file. When I run the program file, it executes properly, but the stored values are not displaying correctly. I'm trying to get them to display in the dollar format, but it's leaving off the last 0. Can someone please offer some assistance. Here's what I did.
File 1
public abstract class Customer//Using the abstract class for the customer info
private String name;//customer name
private String acctNo;//customer account number
private int branchNumber;//The bank branch number
//The constructor accepts as arguments the name, acctNo, and branchNumber
public Customer(String n, String acct, int b)
    name = n;
    acctNo = acct;
    branchNumber = b;
//toString method
public String toString()
String str;
    str = "Name: " + name + "\nAccount Number: " + acctNo + "\nBranch Number: " + branchNumber;
    return str;
//Using the abstract method for the getCurrentBalance class
public abstract double getCurrentBalance();
}file 2
public class AccountTrans extends Customer //
    private final double
    MONTHLY_DEPOSITS = 100,
    COMPANY_MATCH = 10,
    MONTHLY_INTEREST = 1;
    private double monthlyDeposit,
    coMatch,
    monthlyInt;
    //The constructor accepts as arguments the name, acctNo, and branchNumber
    public AccountTrans(String n, String acct, int b)
        super(n, acct, b);
    //The setMonthlyDeposit accepts the value for the monthly deposit amount
    public void setMonthlyDeposit(double deposit)
        monthlyDeposit = deposit;
    //The setCompanyMatch accepts the value for the monthly company match amount
    public void setCompanyMatch(double match)
        coMatch = match;
    //The setMonthlyInterest accepts the value for the monthly interest amount
    public void setMonthlyInterest(double interest)
        monthlyInt = interest;
    //toString method
    public String toString()
        String str;
        str = super.toString() +
        "\nAccount Type: Hybrid Retirement" +
        "\nDeposits: $" + monthlyDeposit +
        "\nCompany Match: $" + coMatch +
        "\nInterest: $" + monthlyInt;
        return str;
    //Using the getter method for the customer.java fields
    public double getCurrentBalance()
        double currentBalance;
        currentBalance = (monthlyDeposit + coMatch + monthlyInt) * (2);
        return currentBalance;
}File 3
    public static void main(String[] args)
//Creates the AccountTrans object
        AccountTrans acctTrans = new AccountTrans("Jane Smith", "A123ZW", 435);
        //Created to store the values for the MonthlyDeposit,
        //CompanyMatch, MonthlyInterest
        acctTrans.setMonthlyDeposit(100);
        acctTrans.setCompanyMatch(10);
        acctTrans.setMonthlyInterest(5);
        DecimalFormat dollar = new DecimalFormat("#,##0.00");
        //This will display the customer's data
        System.out.println(acctTrans);
        //This will display the current balance times 2 since the current
        //month is February.
        System.out.println("Your current balance is $"
                + dollar.format(acctTrans.getCurrentBalance()));
    }

Get a hair cut!
h1. The Ubiquitous Newbie Tips
* DON'T SHOUT!!!
* Homework dumps will be flamed mercilessly. [Feelin' lucky, punk? Well, do ya'?|http://www.youtube.com/watch?v=1-0BVT4cqGY]
* Have a quick scan through the [Forum FAQ's|http://wikis.sun.com/display/SunForums/Forums.sun.com+FAQ].
h5. Ask a good question
* Don't forget to actually ask a question. No, The subject line doesn't count.
* Don't even talk to me until you've:
    (a) [googled it|http://www.google.com.au/] and
    (b) had a squizzy at the [Java Cheat Sheet|http://mindprod.com/jgloss/jcheat.html] and
    (c) looked it up in [Sun's Java Tutorials|http://java.sun.com/docs/books/tutorial/] and
    (d) read the relevant section of the [API Docs|http://java.sun.com/javase/6/docs/api/index-files/index-1.html] and maybe even
    (e) referred to the JLS for "advanced" questions.
* [Good questions|http://www.catb.org/~esr/faqs/smart-questions.html#intro] get better Answers. It's a fact. Trust me on this one.
    - Lots of regulars on these forums simply don't read badly written questions. It's just too frustrating.
      - FFS spare us the SMS and L33t speak! Pull your pants up, and get a hair cut!
    - Often you discover your own mistake whilst forming a "Good question".
    - Often you discover that you where trying to answer "[the wrong question|http://blog.aisleten.com/2008/11/20/youre-asking-the-wrong-question/]".
    - Many of the regulars on these forums will bend over backwards to help with a "Good question",
      especially to a nuggetty problem, because they're interested in the answer.
* Improve your chances of getting laid tonight by writing an SSCCE
    - For you normal people, That's a: Short Self-Contained Compilable (Correct) Example.
    - Short is sweet: No-one wants to wade through 5000 lines to find your syntax errors!
    - Often you discover your own mistake whilst writing an SSCCE.
    - Often you solve your own problem whilst preparing the SSCCE.
    - Solving your own problem yields a sense of accomplishment, which makes you smarter ;-)
h5. Formatting Matters
* Post your code between a pair of {code} tags
    - That is: {code} ... your code goes here ... {code}
    - This makes your code easier to read by preserving whitespace and highlighting java syntax.
    - Copy&paste your source code directly from your editor. The forum editor basically sucks.
    - The forums tabwidth is 8, as per [the java coding conventions|http://java.sun.com/docs/codeconv/].
      - Indents will go jagged if your tabwidth!=8 and you've mixed tabs and spaces.
      - Indentation is essential to following program code.
      - Long lines (say > 132 chars) should be wrapped.
* Post your error messages between a pair of {code} tags:
    - That is: {code} ... errors here ... {code}
    - OR: [pre]{noformat} ... errors here ... {noformat}[/pre]
    - To make it easier for us to find, Mark the erroneous line(s) in your source-code. For example:
        System.out.println("Your momma!); // <<<< ERROR 1
    - Note that error messages are rendered basically useless if the code has been
      modified AT ALL since the error message was produced.
    - Here's [How to read a stacktrace|http://www.0xcafefeed.com/2004/06/of-thread-dumps-and-stack-traces/].
* The forum editor has a "Preview" pane. Use it.
    - If you're new around here you'll probably find the "Rich Text" view is easier to use.
    - WARNING: Swapping from "Plain Text" view to "Rich Text" scrambles the markup!
    - To see how a posted "special effect" is done, click reply then click the quote button.
If you (the newbie) have covered these bases *you deserve, and can therefore expect, GOOD answers!*
h1. The pledge!
We the New To Java regulars do hereby pledge to refrain from flaming anybody, no matter how gumbyish the question, if the OP has demonstrably tried to cover these bases. The rest are fair game.

Abstract class, a question

Similar Messages

Maybe you are looking for