Why abstrace method exist in interface

when I see junit source code .I see code about this:
public interface Test {
      * Counts the number of test cases that will be run by this test.
     public abstract int countTestCases();
      * Runs a test and collects its result in a TestResult instance.
     public abstract void run(TestResult result);
}I know that abstract method is for abstract class.But why it exist in this interface.

All interface methods are abstract, even if you don't declare them as such, because they don't have implementation where they're declared.
It's generally considered better form not to bother with "public" or "abstract" since they're redundant, but some people prefer to be explicit.

Similar Messages

Should I denote that a method satisfies an interface?

When writing a class which has ("satisfies") 1 or more interfaces, should I note somehow (e.g. in an XML comment, or with an attribute) that a particular method was added for one of the interfaces?
For example, the IComparable interface requires an int
CompareTo(Object) method.
I know I don't need to do anything other than implement the appropriate methods, but for maintainability and ease of understanding are there any "best practices"
for letting others know why the method exists?

Yes. Your inclination is sound. You should leave a comment in the method's source code and/or larger documentation.
// Implements IComparable interface
in the method source should do the trick, allowing those who will be reading the code closely (you later on, or someone else maintaining, modifying, or adapting it) to easily and rapidly acertain why the method exists.
If the method is part of a promoted API, it can also be mentioned in the API docs (the form of which will vary based on what documentation system you're using).
Even if you're not fully committed to literate programming, in which
an explanation of the code is considered co-equal to the code itself, it is an excellent practice to use comments in the program source and notes in the API documentation to explain how the program works, why it is defined and implemented as it is, and how
to use it.

How to add new payment methods to an existing EDI interface to bank

Hello:
<b>Requirment:</b> Need to add two new payment methods to an existing EDI interface to bank. As of now only USD EFT's are sent. With the new set up we need to be able to send CAD and USD checks and CAD EFT's to that particualr bank.
<b>Scenario:</b> The payment methods are all set up in the payment program. I need two separate variants on the program RFF0EDI1 thats triggers the EDI file. The trigger of the EDI after the payment run should have a different variant... but the message type ought to be the same.
Can some one please exlpain how I should go about setting this up. Thank you.

I figured out the way to do it myself, after poking around the system for hours together.
All I need to do was to make config changes in FI12- define the posting rules and the bank accounts the checks needs to be drawn against. Also adding the payment method "C" in the DME section of the FI12. Next check and see if the Idoc message types have been set to what was required by clicking on "EDI partner profile in the DME section. Also to have different varaints for the program RFF0EDI1 , I just had to goto SE38 select the program and create the new variant. For enabling EDI I had to do some config changes in FBZP- MAINTAIN PAYMENT PROGRAM CONFIGURATION: PAYMENT METHODS in country, Delete the entry made in the "Name of print data set" in the form print section and enter "RFF0EDI" under "Name of the print program" in the form data section. If anybody needs any other information , please let me know. Thanks everyone.

Why is it that the interfaces cannot have static methods?

why is it that the interfaces cannot have static methods?

Interfaces contain polymorphic methods. Static methods are not polymorphic, and therefore would not make any sense to be in interfaces.

Is there a quick fix option for implementing the unimplemented methods for an interface?

Hi guys,
It's a useful feature and it seems to exist in raw Eclipse. I'm aware of the Source -> Override/Implement methods, but this is clunky when you could hover over an interface and hit Ctrl+1 and auto-implement all methods for that interface (which seems to be pretty much most use cases for me). At the moment the quick-fix only seems to have renaming options. Is there something wrong with my configuration?
If not, is there a way to make feature requests? :-))
Thanks!
Jarrod

I have safari on my iPone and like it there... thought that I would give it a try. Well, IE just started to slow to a paint drying speed and then wouldn't load anything. Safari was installed but crashed in threee seconds each occuarnce. No reason, no error message.
I downloaded (eventually) Firefox... loaded it, chose my extentions and have never had a problem with it since. I unloaded 5 times (gave up on) Safari, reset IE, reinstalled the extentions for that and now it is working after cleaning all of the files, passwords, forms autocomplete, temp files, etc.
Firefox works and all of my freinds and kids use it. That is why it is so good. Remember, if your car worked like your PC you wold junk it right away. Reliability is not in the MS dictionary. It is something that you have to add via tons of fixes, add-ons and program balancing so that conflicts don't occer. I want my MAC, I want my, I want my MAC...

Method in abstract interface

Suppose I have an abstract interface which has one method:
public abstract interface IParent {
public void setSignal(int signal);
}And I have a concrete interface inherited from IParent which also have one method:
public interface IChild extends IParent {
public void setSpeed(int speed);
}If I define a class which implements IChild it only asks me to implement setSpeed method.
public class Test implements IChild {
}Why it does not ask me to implement setSignal method of IParent interface?

Suppose I have an abstract interface which has one method:
Every interface is implicitly abstract.
public void setSignal(int signal);
Every method declaration in the body of an interface is implicitly public.
And I have a concrete interface inherited from IParent which also have one method:
Every interface is implicitly abstract.
If I define a class which implements IChild it only asks me to implement setSpeed method.'It' being what?
Why it does not ask me to implement setSignal method of IParent interface?I have no idea what 'it' you're talking about, but the Test class will not compile.

Why getRequestDispatcher method cannot accept full URL?

Examples*
This code works well:
public void doPost(HttpServletRequest request, HttpServletResponse response)
               throws ServletException, IOException {
          String url = "/jsp/pageStart.jsp";
                /* requestDispatcher is NOT null */
          RequestDispatcher requestDispatcher = getServletContext()
                    .getRequestDispatcher(url);
          requestDispatcher.forward(request, response);
     }This code doesn't work, get NullPointerException, requestDispatcher is null:
public void doPost(HttpServletRequest request, HttpServletResponse response)
               throws ServletException, IOException {
          String url = "http://localhost:8080/mymvc/jsp/pageStart.jsp";
                /* requestDispatcher is null */
          RequestDispatcher requestDispatcher = getServletContext()
                    .getRequestDispatcher(url)
          requestDispatcher.forward(request, response);
Notes*
- JSP path is \src\main\webapp\jsp\pageStart.jsp
- I am sure, I can manually open 'http://localhost:8080/mymvc/jsp/pageStart.jsp', just copy and paste this url into address of new browser window.
- Base url is http://localhost:8080/mymvc/servlet/ControllerServlet
- I use Servlet mapping:
<servlet-mapping>
     <servlet-name>ControllerServlet</servlet-name>
     <url-pattern>/servlet/*</url-pattern>
</servlet-mapping>
<servlet>
     <servlet-name>ControllerServlet</servlet-name>
     <servlet-class>controller.ControllerServlet</servlet-class>
</servlet>
Questions*
1. Why getRequestDispatcher method cannot accept full URL?
2. Could you please explain to me the reason why ? and please provide me the better resolutions.
Thanks u in advance!

As per Java API documentation:
ServletContext#getRequestDispatcher(String path)
The pathname must begin with a "/" and is interpreted as relative to the current context root.
For details: [http://java.sun.com/javaee/5/docs/api/javax/servlet/ServletContext.html#getRequestDispatcher(java.lang.String)|http://java.sun.com/javaee/5/docs/api/javax/servlet/ServletContext.html#getRequestDispatcher(java.lang.String)]
ServletRequest.html#getRequestDispatcher(java.lang.String)
To allow RequestDispatcher objects to be obtained using relative paths that are relative to the path of the current request (not relative to the root of the ServletContext), the getRequestDispatcher method is provided in the ServletRequest interface. The pathname specified may be relative, although it cannot extend outside the current servlet context.
For details : [http://java.sun.com/javaee/5/docs/api/javax/servlet/ServletRequest.html#getRequestDispatcher(java.lang.String)|http://java.sun.com/javaee/5/docs/api/javax/servlet/ServletRequest.html#getRequestDispatcher(java.lang.String)]

Static method allowed in interface?

Hello,
I've written the following code:
package a.b.c.d;
import java.util.Map;
public interface Adapter
public void execute(Mapping mapping) throws Exception;
public static Map getParameters( ) throws Exception;
My compiler complains thusly:
"Adapter.java": Error #: 217 : modifier static not allowed here at line 8, column 23
Is it illegal then to declare a static method in an interface and if so why? Thanks in advance!
-Exits

An interface itself is just a contract that says "I will implement thus-and-such methods with such-and-such a signature." The interface has no "meat" to it, so it can't implement the static.
Now you're thinking, if MyClass implements MyInterface, then MyClass can just have a static method that is the one on MyInterface. The problem is with how you're getting your MyInterface-type object. You can do it like this:
MyInterface obj = new MyClass();
obj.myStaticMethod(); //Bzzzzzzzt! blows up at compile time...or...
MyInterface obj = someMethodThatReturnsClassImplementingMyInterface();
obj.myStaticMethod(); //Bzzzzzt! same problemYou can't call a static method on an instance; you have to call it on the class,
MyClass.myStaticMethod();You can't call it on the interface directly because, again, the interface has no guts inside it. There's really no reason to put a static method on an interface because that's not what interfaces are for. If MyClass needs a static, put it there.

Why the method can be called in this way?

Hi all,
The following is JAVA SWING TREE custom data models program. There are two files in the program: one is TestFrame.java, and the other is MyDataModel.java. I only posted the important part on the Forum.My question is how method getChild(...) in MyDataModel.java was called in the program? Why I couldn't see the statement like tree.getChild(..) in TestFrame.java? After adding PRINT statements, I know the method getChild(..) was called automatically when object tree was initialized , but I don't know why. Thank you in advance.
======
TestFrame.java
// Imports
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
class TestFrame extends JFrame
// Instance attributes used in this example
private JPanel topPanel;
private JTree tree;
private JScrollPane scrollPane;
// Constructor of main frame
public TestFrame()
// Create a new tree control
MyDataModel treeModel = new MyDataModel( root );
tree = new JTree(treeModel);
=========
==========
MyDataModel.java
import javax.swing.tree.*;
class MyDataModel extends DefaultTreeModel
private DefaultMutableTreeNode root;
private String rootName = "";
public MyDataModel( TreeNode root )
super( root );
DefaultMutableTreeNode parentNode = (DefaultMutableTreeNode)root;
rootName = (String)parentNode.getUserObject();
System.out.println("rootName is: "+rootName);
public Object getChild( Object parent, int index )
DefaultMutableTreeNode parentNode = (DefaultMutableTreeNode)parent;
String parentName = (String)parentNode.getUserObject();
System.out.println("parentName is: "+parentName);
if( parentName.equals( rootName ) )
return super.getChild( parent, index );
else
return new DefaultMutableTreeNode( cardArray[index] );
}

This is the first time I saw this usage. I understood it now, but I was afraid I missed some important concepts on "interface as parameter in the constructor". Therefore, I am wondering where I can find some online document about it in order to understand the usage clearly.
For example, if there are a few method implementations of interface TreeModel in MyDataModel.java, which methods will it call after calling JTree constructor? all methods or only part of them?
Thanks

Why does EJB needs two interface???

Hi All,
This has been asked by many ppl and many of you might be having
the correct answer for it. Please tell me....
Why does EJB needs two interface (Home and Remote Interface)?. Why not one?
Thanx to all...
Regards
GoodieGuy

Hi Goodie ,
Its good question and its a very valid one , one has to have doubt
why two , why not one ..
Here the answer goes ..
First of all you need to understand that its a distributed computing technique ie I mean lot of people will be accessing the bean at the same time , right ? OK , you cann't access the bean directly.
and lastly the stateless and entity beans do instance pooling.
The very purpose of having two interfaces is
1) To differnentiate the bussiness logic and life cycle methods .
2) The home interface inititates life cycle methods like creation , destruction etc .
3) There are lot of beans in the container , and through home you are
creating the instance or accessing one of them .
4) Once you have home object using it we get the remote object ie the instance of the bean that you want to access if stateless any bean can be called , if statefull depending upon the parameter in create method that respective bean is created and invoked .
In ejb 1.0 and 1.1 even though the bean and the client are in same jvm its assumed that they are remote and in 2.0 Ver we have local this is to avoid network traffic .
Hope you have got the answer , but if u still need clarification
read EBRoman book first and second chapters thoroughly and then proceed
a head.
Bye
Mahesh L.
============

Automatic payment program - error No permitted payment method exists

Hi All,
I am doing the automatic payment run and done all the necessary config in FBZP.
1) Created the payment program at country level and assigned payment program
2) Created the payment method at company code level for check and assign the Check Form
3) Coming to Bank determination:
   a) Ranking order : given the payment method(A -> Check) ,currency(MYR), ranking order (1) and assigned to house bank (CIMB)
   b) Bank accounts : given house bank , payment method ,currency, account ID and clearing account number.
4) assigned the payment method (A) in vendor master.
when i run the payment run for the vendor in F110 for company code system hitting below errors:
> -
Payment method selection additional log----
> Payment method selection for items due now to the amount of MYR      112,909.38-
> Payment via payee/payer 0550000008
> Payment method "A" is being checked
> Payment with 28 print items, only 16 are allowed
> No permitted payment method exists
Information re. vendor 500000598 / paying company code 0546 ...
......payment not possible because of reported error
End of log
Job finished
please can any body help me on this. I done the same config in DEV and QAS. there working fine with out any issue.   but coming to PRD its giving problem. i double confirm the config in DEV to pRD every thing fine and same.
thanks.
Sandhya.

Hi...
I did check the 1) vendor address -> No gaps
2) My one is check printing not bank transfer
3) I did check all the vendor line items no payment blocks. user already unblock the relevent item to make payment.
Here weird thing is system hitting the same above mentioned error even I updated the payment method(C) and house bank (CIMB) in each and every line item of vendor invoice.
Thanks,
Sandhya.

Generic arguments in a Method on an interface.

Hi all,
I'm having trouble with the following code:
Basically this is what i want:
the Classes:
public class SuperClass
public class ClassA extends SuperClass
public class ClassB extends SuperClass
public class ClassC extends SuperClass
The interface
public interface interfaceX
   public methodX(SuperClass A);
Implementation of the interface
public class classX implements interfaceX
     public methodX(ClassA A)
}My problem is on the declaration of the interface interfaceX in the class classX.
How can i do such thing?
I'm trying to avoid the "correct" declaration. this is:
public methodX(SuperClass A)
        { ... }because I have a couple of class that extends that interface with deferents arguments, all of them extending from the SuperClass.
I know i could use the instanceof keywork, but i'm trying to avoid the extra checking...
Thanks in advance for any help!!
Edited by: ValdemarP on Mar 29, 2010 1:55 AM

i know I'm changing the contract, but only the arguments. if you notice, the new arguments is child of class SuperClass... How can I do this? Declare an method in an interface that accepts an arguments of some class and implement that interface, with argument that are children of the arguments declared in the interface... hope i was more clear this time... :(
Example. I can do this on an interface:
public void MethodListGeneric(List<? extends SuperClass> xpto )and during the implementation of the interface, I can declare the method using any arguments for the generic list, that extends SuperClass.
Example:
public class xpto extends InterfaceX
    public void MethodListGeneric(List<ClassA> xpto )
     // in here I've use ClassA insted of SuperClass
}Edited by: ValdemarP on Mar 29, 2010 3:15 AM
Edited by: ValdemarP on Mar 29, 2010 3:15 AM

Error message: Multiple definitions exist for interface

Hi experts,
I am developing a scenario that involves a BPM, that receives a certain abstract interface, and sends out another abstract interface.
I have created a service interface for the result abstract interface.
I have tested the before BPM and it worked, but now it has stopped working.
In the java ui no errors are seen, and the BPM activates successfully, but in transaction SXI_CACHE the BPM is in status 99, and in the activation log there is a message saying: Multiple definitions exist for interface [Name of the result abstract interface].
I have tried activating the service interface, the BPM, and doing a delta cache refresh, but it didn't change.
What can I do to solve this problem?
Thanks in advance,
Gershon Osmolovski

Hi Gershon,
Try following thing, might help.
Go to ID and check which communication component you have created. Check if there is any other inactive version of it. If it is existing.Delete it.
Edit and activate the original Communication component and do cache refresh.

F110 error: No permitted payment method exists

Hi all,
I am trying to learn the F110 payment method. I have a vendor and a GL to which I have posted an invoice to be paid. When I schedule a payment run, my log looks like this:
Payment method selection additional log FZ
Payment method selection for items due on 06.04.2009 to the amount of USD 90 FZ
Payment method "C" is being checked FZ
Bank details are being checked FZ
System reads house banks and checks if they are allowed FZ
Our bank BANK is being checked FZ
No amount has been scheduled for currency USD and at least 001 days' life FZ
House bank is selected ... FZ
No permitted payment method exists FZ
Information re. vendor VENDOR/ paying company code MLBR ... FZ
... payment not possible because of reported error FZ
I have checked and made sure that the following are properly configured:
1. Vendor master (adress of vendor, payment method)
2. Bank data (house bank, payment method, ranking(using only one bank), subaccount)
3. Document (payment method on the invoice).
4. Payment method in country and company code
Please help. What am I doing wrong? I cant think of anything else that I have overlooked.
Will award points for your help.
Thanks in advance,
TW

Thanks for the reply.
I am using 999999.... (all 9s) to tell SAP that it can use all the available funds in the bank to make the payment. Can you also explain what
"No amount has been scheduled for currency USD and at least 001 days' life " means?
Thanks again,
TW

Error - No permitted payment method exists

Hi guys,
I'm trying to create a Automatic Payment Transactions (transaction F110) using Custumer account.
In the job log, the system displays the error message:
> No permitted payment method exists.
If I edit the proposal and reallocate the document, the system is not populate the ID of House Bank (Payment Control) that is required.
If I enter the ID and save the proposal, the program runs normally.
How can I do to system populate the ID of House Bank?
Thanks,
Thiago Cavalcante

I've already checked this log.
06.04.2009 17:29:03 >            Payment method selection additional log                                             FZ
06.04.2009 17:29:03 > Payment method selection for items due on 06.04.2009 to the amount of BRL        1.523,87      FZ
06.04.2009 17:29:03 > Payment method "D" is being checked                                                            FZ
06.04.2009 17:29:03 > Bank details are being checked                                                                 FZ
06.04.2009 17:29:03 >   System reads house banks and checks if they are allowed                                      FZ
06.04.2009 17:29:03 > Our bank UNIB is being checked                                                                 FZ
06.04.2009 17:29:03 > Bank different from the specified bank ITAUF in master record or items                         FZ
06.04.2009 17:29:03 > Our bank ITAUF is being checked                                                                FZ
06.04.2009 17:29:03 > No amount has been scheduled for currency BRL and at least 000 days' life                      FZ
06.04.2009 17:29:03 >   House bank is selected ...                                                                   FZ
06.04.2009 17:29:03 > No permitted payment method exists                                                             FZ
06.04.2009 17:29:03 Information re. customer 23186 / paying company code FEM ...                                     FZ
06.04.2009 17:29:03 ... payment not possible because of reported error                                               FZ

Why abstrace method exist in interface

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