How Abstract class differ, When we call class to be Abstract data type?

We say as Classes as a realization of Abstract data types, then why should we declare that to be abstract ?
Hope, the key word Abstract in both ADT and abstract classname mean the same.!!!!

No, abstract is in the case of "abstract data type" a more general term, whereas in "abstract class" it is a technical term in Java.
Are you not satisfied with the answers here?
http://forum.java.sun.com/thread.jspa?threadID=5303930&messageID=10297137#10297137

Similar Messages

New Effective CAL essay: How do I create an abstract data type in CAL?

How do I create an abstract data type in CAL? An abstract data type is one whose internal representation can be changed without needing to modify the source code of client modules that make use of that type. For software maintainability, it is a good idea to make a type that is subject to change or enhancement into an abstract data type. Another reason to create an abstract data type is to enforce invariants for values of the type that can only be ensured by using constructor functions (i.e. functions that return values of that type). In principle it is simple to create an abstract data type in CAL. For an algebraic data type, make the type constructor public and all data constructors private. For a foreign data type, make the type constructor public and the implementation scope private. If a scope qualifier is omitted, the scope is taken to be private. For example, the Map algebraic data type has the public type constructor Map and the data constructors Tip and Bin are each private, so it is an abstract data type. /** A map from keys (of type {@code k@}) to values (of type {@code a@}). */ data public Map k a = private Tip | private Bin size :: !Int key :: !k value :: a leftMap :: !(Map k a) rightMap :: !(Map k a); There are a number of invariants of this type: the size field represents the number of elements in the map represented by its Bin value. The keys in leftMap are all less than key, which in turn is less than all the keys in rightMap. In particular, non-empty Map values can only be created if the key parameter type is a member of the Ord type class. Values of the Map type can be created outside the Cal.Collections.Map module only by using constructor functions such as insert: insert :: Ord k => k -> a -> Map k a -> Map k a; public insert !key value !map = ... The owner of the Cal.Collections.Map module must ensure that all invariants of the Map type are satisfied, but if this is done, then it will automatically hold for clients using this function. Some examples of foreign abstract data types are Color, StringNoCase and RelativeDate: data foreign unsafe import jvm private "java.awt.Color" public Color; data foreign unsafe import jvm private "java.lang.String" public StringNoCase; data foreign unsafe import jvm private "int" public RelativeDate; The private implementation scope for Color means that a foreign function whose type involves Color can only be declared in the Cal.Graphics.Color module where the Color type is defined. A foreign function declaration involving the Color type relies on the compiler knowing that the Color type corresponds to java.awt.Color to resolve the corresponding Java entity i.e. it must know about the implementation of the Color type. Having a private implementation scope means that the Color type can be changed to correspond to a different Java class, or indeed to be an algebraic type, without the risk of breaking client code. In all these three cases there are useful, and different, design reasons to adopt a private implementation scope: For RelativeDate, the Java implementation type int represents a coded Gregorian date value in the date scheme used by Crystal Reports. Not all int values correspond to valid dates, and the algorithm to map an int to a year/month/day equivalent is fairly complicated, taking into account things like Gregorian calendar reform. Thus, it is desirable to hide the implementation of this type. For StringNoCase, the implementation is more straightforward as a java.lang.String. The reason to adopt a private implementation scope is to ensure that all functions involving StringNoCase preserve the semantics of StringNoCase as representing a case-insensitive string value. Otherwise it is very easy for clients to declare a function such as: foreign unsafe import jvm "method replace" replaceChar :: StringNoCase -> Char -> Char -> StringNoCase; which does not handle case-insensitivity correctly, but is a perfectly valid declaration. This declaration results in a compilation error when it is placed outside the module in which StringNoCase is defined because of the private implementation scope of StringNoCase. For Color, the issue is somewhat more subtle. The java.awt.Color implementation type is semantically the same as the CAL Color type. The problem is that java.awt.Color is mutable (since it can be sub-classed to create a mutable type). It is preferable for a first-class CAL type to not be mutable, so we simply make the implementation scope private to ensure that this will be the case. A somewhat less encapsulated kind of abstract data type can be created using friend modules and protected scope. For example, if an algebraic type is public, and all its data constructors are protected, then the data constructors can be accessed in the friend modules of the module in which the type is defined. Effectively this means that the implementation of the semantics of the type stretches over the module in which the type is defined, and all of its friend modules. These must all be checked if the implementation of the type is modified. Given the merits of abstract data types discussed above, it is perhaps surprising that most of the core types defined in the Prelude module are not abstract data types. For example: Boolean, Char, Int, Double, String, List, Maybe, Either, Ordering, JObject, JList, and all record and tuple types are non-abstract types. There are different reasons for this, depending on the particular type involved. For example, Boolean, List, Maybe, Either and Ordering are all rather canonical algebraic data types with a long history in functional languages, with many standard functions using them. They are thus guaranteed never to change. In addition, their values have no particular design invariants that need to be enforced via constructor functions. Exposing the data constructors gives clients some additional syntactic flexibility in using values of the type. For example, they can pattern match on the values using case expressions or let patterns. Essentially the same explanation holds for record and tuple types. Although non-tuple record types are less canonical, they do correspond to the fundamental notion of an anonymous named-field product type. The "anonymous" here simply means that the programmer can create an entirely new record type simply by creating a value; the type does not have to be declared anywhere prior to use. Char, Int, Double, String, JObject and JList are foreign types where in fact part of the semantics of the type is that we want clients to know that the type is a foreign type. For example, we want clients to know that Prelude.Int is essentially the Java primitive unboxed int type, and has all the semantics you would expect of the Java int type i.e. this is quite different from RelativeDate which is using int as its implementation type in a very tactical way that we may choose to change. One can think of a public foreign type declaration with public implementation scope as simply introducing the Java type into the CAL namespace. One interesting point here is with CAL's naming convention for public foreign types. We prefix a type name by "J" (for "Java") for foreign types with public implementation type such that the underlying Java type is mutable. This is intended as mnemonic that the type is not a pure functional type and thus some caution needs to be taken when using it. For example, Prelude.JObject has public Java implementation type java.lang.Object. In the case where the underlying Java type is not mutable, we do not use the prefix, since even though the type is foreign; it is basically a first class functional type and can be freely used without concern. For example, Prelude.String has public Java implementation type java.lang.String. In the case where the implementation type is private, then the fact that the type is a foreign type, whether mutable or not, is an implementation detail and we do not hint at that detail via the name. Thus Color.Color has as its private Java implementation type the mutable Java type java.awt.Color. When creating abstract data types it is important to not inadvertently supply public API functions that conflict with the desired public semantics of the type. For example, if the type is publicly a pure-functional (i.e. immutable) type such as Color, it is important not to expose functions that mutate the internal Java representation. A more subtle case of inadvertently exposing the implementation of a type can occur with derived instances. For example, deriving the Prelude.Outputable and Prelude.Inputable type classes on a foreign type, whose implementation type is a mutable Java reference type, allows the client to gain access to the underlying Java value and mutate it
(by calling Prelude.output, mutating, and then calling Prelude.input). The solution in this case is to not derive Inputable and Outputable instances, but rather to define a custom Inputable and Outputable instance that copies the underlying values.

Hi Pandra801,
When you create a the external content type, please try to add a filter based on your select statement.
http://arsalkhatri.wordpress.com/2012/01/07/external-list-with-bcs-search-filters-finders/
Or, try to create a stored procedure based on your select statement, then create ECT using the SQL stored procedure.
A step by step guide in designing BCS entities by using a SQL stored procedure
http://blogs.msdn.com/b/sharepointdev/archive/2011/02/10/173-a-step-by-step-guide-in-designing-bcs-entities-by-using-a-sql-stored-procedure.aspx
I hope this helps.
Thanks,
Wendy
Wendy Li
TechNet Community Support

What is Abstract Data type ?

Shall i call a class to be an Abstract data type ?

jverd wrote:
I do not agree. For one thing, I'd consider classes realizations or implementations of ADTs. That nitpick aside, however, the easiest counterexample is a class with no member variables. The "D" of "ADT" is missing there. I wouldn't consder java.lang.Math and ADT, just a collection of functions and constants.I wouldn't say being implemented in a specific language takes anything away from an ADT. An implemented ADT is also an ADT.
Being an ADT doesn't require the existence of state. This was what you meant with "no member variables" right? ADTs can have or not have state.
Your final counterexample concerns so called free functions and constants (static in Java). They should be viewed as part of an ADT definition. But okay, Math itself cannot be considered an ADT so not every class, interface and enum is an ADT as I claimed. Sometimes they're used as namespaces for free functions and constants that have no natural home. Functions and constants associated with primitives have to go somewhere for example. But this usage is atypical.

HEELLLLP with abstract data types(ie. interfaces)

Hello Java World,
I have a few questions regarding abstract data types(ADT) such as interfaces, etc.
1. Which of the following is allowed in Java ?
interface TA extends student, Employee
class teachAssist implements TA, Cloneable, Sortable{..}
2. ADTs cannot be instantiated only extended/implemented(coded)??
3. Can a interface implements/extend classe(s)?
4. Why is a Vector not an ADT? Is it because it contains implementations for its some of its methods?
Thanks for the help, in advance!!
RahimS

Hello Java World,
I have a few questions regarding abstract data
types(ADT) such as interfaces, etc.
1. Which of the following is allowed in Java ?
interface TA extends student, Employee
{...}Allowed (if student and Employee are also Interfaces).
class teachAssist implements TA, Cloneable,
Sortable{..}Allowed.
>
2. ADTs cannot be instantiated only
extended/implemented(coded)??True.
3. Can a interface implements/extend classe(s)?No. An interface simply defines a skeleton...says what methods are present in classes that implement it...therefore an interface cannot 'implement' anything. It may however extend other Interfaces.
4. Why is a Vector not an ADT? Is it because it
contains implementations for its some of its methods?A Vector is not an ADT because it is fully implemented (it contains implementations for ALL of its methods).
>
>
Thanks for the help, in advance!!
RahimS

Abstract data types - index List

Hi,
What does it mean 'Index List' abstract data type? I've searched on Google and can't find any reference to the term 'Index List'.
Does anybody know any examples of distinct classes for this data type?
Any help really appreciated.
Thanks

Hi,
What does it mean 'Index List' abstract data type? I've searched on Google and can't find any reference to the term 'Index List'.
Does anybody know any examples of distinct classes for this data type?
Any help really appreciated.
Thanks

Abstract data types??

I am just learning about data structures and am having some difficulty. Can someone please define what an abstract data type means and what it is. A simple example would be great
Thanks

The concept of an Abstract Data Type maps nicely to the concept of a Class in Java.

Conversion failed when converting the varchar value 'undefined' to data typ

Conversion failed when converting the varchar value 'undefined' to data type int.
hi, i installed oracle insbridge following the instruction in the manual. in rate manager, when i tried to create a new "Normal rating" or "Underwriting", im getting the following exception
Server Error in '/RM' Application.
Conversion failed when converting the varchar value 'undefined' to data type int.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Data.SqlClient.SqlException: Conversion failed when converting the varchar value 'undefined' to data type int.
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace:
[SqlException (0x80131904): Conversion failed when converting the varchar value 'undefined' to data type int.]
System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +1948826
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4844747
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194
System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2392
System.Data.SqlClient.SqlDataReader.HasMoreRows() +157
System.Data.SqlClient.SqlDataReader.ReadInternal(Boolean setTimeout) +197
System.Data.SqlClient.SqlDataReader.Read() +9
System.Data.SqlClient.SqlCommand.CompleteExecuteScalar(SqlDataReader ds, Boolean returnSqlValue) +50
System.Data.SqlClient.SqlCommand.ExecuteScalar() +150
Insbridge.Net.Fwk.DAO.DataAccess.ScalarQuery(String connectionString, String command, Transaction transType, Object[] procParams) +110
[Exception: Cannot Execute SQL Command: Conversion failed when converting the varchar value 'undefined' to data type int.]
Insbridge.Net.Fwk.DAO.DataAccess.ScalarQuery(String connectionString, String command, Transaction transType, Object[] procParams) +265
Insbridge.Net.Fwk.DAO.SqlProcessor.ExecuteScalarQueryProc(String subscriber, String datastore, String identifier, String command, Transaction transType, Object[] procParams) +101
Insbridge.Net.Fwk.DAO.SqlProcessor.ExecuteScalarQuery(String subscriber, String identifier, String command) +22
Insbridge.Net.RM.IBRM.ExeScalar(String cmd, Object[] paramsList) +99
Insbridge.Net.RM.Components.Algorithms.AlgEdit.Page_Load(Object sender, EventArgs e) +663
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
System.Web.UI.Control.OnLoad(EventArgs e) +99
System.Web.UI.Control.LoadRecursive() +50
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627
my insbridge versions are as follows
IBRU 4.0.0 Copyright ©2010, Oracle. All rights reserved. - Version Listing
RMBUILD.DLL 4.0.0.0 (x86)
SRLOAD.DLL 3.13.0 (x86)
IBRM v04.00.0.17
IB_CLIENT v04.00.0.00
RM.DLL 4.00.0 (x86)
IBFA 3.0.2
OS: Windows Server 2003
DB: Sql Server 2008
Browser: IE8
how do i solve this, please help

This is an error due to conversion failed from character string to int datatype. Infact, the table column contains "NO" value which you are trying to convert to Int/SUM which is illegal. Without your code and table structure, its difficult to pinpoint your
actual issue. But check, all columns for value "NO".

Accessing data from an abstract data type

I've been trying to find a way to split up a comma in delimited string PL/SQL, and the following article has helped me do that:
http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:8861471892664
Basically, the solution calls for creating a simple data type which looks like this:
create or replace type myTableType as table of
numberThis will hold the parsed data, which is populated by calling the str2tbl function. But the article doesn't explain how to access the data inside this table once it's been populated.
For example, I create the type myTableType and the function str2tbl, and run this query:
SQL> select str2tbl('4,2,3,4') from dual;
STR2TBL('4,2,3,4')
MYTABLETYPE(4, 2, 3, 4)The function returns a table of type myTableType, but I have no idea how access or index the data. I want to be able to access the 4, the 2, the 3, or the 4 of the result that is returned in the above example. Here's what I've tried:
SQL> select temp(1) from (select str2tbl('4,2,3,4') as temp from dual);
select temp(1) from (select str2tbl('4,2,3,4') as temp from dual)
ERROR at line 1:
ORA-00904: "TEMP": invalid identifierI get the invalid identifier error on pretty much any attempt to get to the data. This seems to be something that's easy to do but I just can't figure it out. Any help would be appreciated, thanks!

Have a look at this thread and scroll all the way to the bottom
http://asktom.oracle.com/pls/ask/f?p=4950:8:11331947847331890504::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:110612348061,
Regards,
Steve Rooney

Japanese characters alone are not passing correctly (passing like ??? or some unreadable characters) to Adobe application when we create input variable as XML data type. The same solution works fine if we change input variable data type to document type a

Dear Team,
Japanese characters alone are not passing correctly (passing like ??? or some unreadable characters) to Adobe application when we create input variable as XML data type. The same solution works fine if we change input variable data type to document type. Could you please do needful. Thank you

Hello,
most recent patches for IGS and kernel installed. Now it works.

Call Oracle procedure with custom data type within Java and Hibernate

I have a custom date TYPE in Oracle
like
CREATE TYPE DATEARRAY AS TABLE OF DATE;
and I have a Oracle function also
like
CREATE OR REPLACE FUNCTION doesContain (list DATEARRAY, val VARCHAR2) RETURN NUMBER
IS
END doesContain;
In my Java class,
I have a collection which contain a list of java.util.Date objects
When I call Oracle function "doesContain", how to pass my java collection to this Oracle function ...
anyone can provide solutions?
Please !!!
Thanks,
Pulikkottil

Vu,
First of all you need to define your types as database types, for example:
create or replace type T_ID as table of number(5)Then you need to use the "oracle.sql.ARRAY" class. You can search this forum's archives for the term "ARRAY" in order to find more details and you can also find some samples via the JDBC Web page at the OTN Web site.
Good Luck,
Avi.

How do I ensure a Map key maps to the correct data type?

Hi,
I have a simple event processing interface, where an Action class processes an event, and optionally generates a response event. I want to store a map of all registered actions, and then select the one matching an incoming event at run time:
// the basic types
public abstract class Event {
protected String type;
protected String data;
public String getType() { return type; }
@Override
public String toString() { return data; }
// an action processes a request event and optionally returns a response event
public interface Action<ReqE extends Event, ResE extends Event> {
public ResE process(ReqE request);
// two simple events
public class Event1 extends Event {
public Event1(String data) { this.type = "ev1"; this.data = data; }
public class Event2 extends Event {
public Event2(String data) { this.type = "ev2"; this.data = data; }
// simple test class
public class Test {
Map<String, Action<? extends Event, ? extends Event>> actions
 = new HashMap<String, Action<? extends Event, ? extends Event>>();
public void run() {
 // source event
 Event1 request = new Event1("hello");
 // register an action - takes an Event1 and returns an Event2
 actions.put(request.getType(), new Action<Event1, Event2>() {
 @Override
 public Event2 process(Event1 req) {
 return new Event2(req.data);
 // run it
 Action<Event, Event> action = getAction(request.getType());
 Event response = action == null ? null : action.process(request);
 System.out.println("Response=" + String.valueOf(response));
public Action<Event, Event> getAction(String type) {
 return (Action<Event, Event>)actions.get(type);
public static void main(String[] args) {
 new Test().run();
}This all works, but the problem is obviously the cast in the getAction() method. I can see what the problem is: there is nothing to stop me registering a handler with the wrong event types:
// register an action - this will fail at runtime as request is an Event1
actions.put(request.getType(), new Action<Event3, Event4>() {
 @Override
 public Event4 process(Event3 req) {
 return new Event4(req.data);
});So that leads to the map declaration. What I think I need to do is change the key of the map from String to... well, I'm not sure what! Some kind of parameterised EventType class that ties in to the event types of the parameterised Action class, so when I call:
Map<????, Action<? extends Event, ? extends Event>> actions = ...
actions.put(????, new Action<Event1, Event2>() {...});the key type ties in to Event1/Event2 so that it ensures the eventual call to "process" will receive the correct types. But this is really getting beyond my knowledge of generics!
So if anybody has any useful pointers on where to go from here I'd be realy grateful.
Cheers,
Barney

The obvious choice for the key would be the type of the request event instead of a plain String.
Thus, declare the map like this:
Map<Class<? extends Event>, Action<?,?>>Below, I've modified your code so that it is typesafe, provided you use the public methods "registerAction" and "getAction".
import java.util.HashMap;
import java.util.Map;
abstract class Event {
 protected String type;
 protected String data;
 public String getType() { return type; }
 @Override
 public String toString() { return data; }
 // an action processes a request event and optionally returns a response event
 interface Action<ReqE extends Event, ResE extends Event> {
 public ResE process(ReqE request);
 // two simple events
 class Event1 extends Event {
 public Event1(String data) { this.type = "ev1"; this.data = data; }
 class Event2 extends Event {
 public Event2(String data) { this.type = "ev2"; this.data = data; }
 // simple test class
 public class EventTest {
 Map<Class<? extends Event>, Action<?,?>> actions
 = new HashMap<Class<? extends Event>, Action<?,?>>();
 public void run() {
 // source event
 Event1 request = new Event1("hello");
 // register an action - takes an Event1 and returns an Event2
 registerAction(Event1.class, new Action<Event1, Event2>() {
 public Event2 process(Event1 req) {
 return new Event2(req.data);
 // run it
 Action<? super Event1,?> action = getAction(Event1.class);
 Event response = action == null ? null : action.process(request);
 System.out.println("Response=" + String.valueOf(response));
 @SuppressWarnings("unchecked")
 public <E extends Event> Action<? super E,?> getAction(Class<E> type) {
 return (Action<? super E,?>)actions.get(type);
 public <E extends Event> void registerAction(Class<E> type, Action<? super E,?> action) {
 actions.put(type, action);
 public static void main(String[] args) {
 new EventTest().run();
 }

Call a method with complex data type from a DLL file

Hi,
I have a win32 API with a dll file, and I am trying to call some methods from it in the labview. To do this, I used the import library wizard, and everything is working as expected. The only problem which I have is with a method with complex data type as return type (a vector). According to this link, import library wizard can not import methods with complex data type.
The name of this method is this: const std::vector< BlackfinInterfaces::Count > Counts ()
where Count is a structure defined as below:
struct Count
Count() : countTime(0) {}
std::vector<unsigned long> countLines;
time_t countTime;
It seems that I should manually use the Call Library Function Node. How can I configure parameters for the above method?

You cannot configure Call Library Function Node to call this function. LabVIEW has no way to pass a C++ class such as vector to a DLL.

Data change after call xml transformation for RAW data type

Hi,
Can someone explain what is workarround or any help for below problem
when call transformation is called for usr02 records, after xml string is generated is showing different data for RAW data type for example content of fields BCODE,PASSCODE etc get convert into different data
for example: content of BCODE fields before xml transformation say -7F8087472FB996E5
after xml transformation it display as f4CHRy+5luU=
why is this so happening? is this known behaviour after xml transformation or it is bug in xml transformation?
thanks in advance.
Regards,
John.

Hi,
I think this is because RAW data is BASE64 encoded when using CALL TRANSFORMATION.
Old post, but did you ever find a way to change that?
Thanks

Calling Idoc structure in creating Data Type

Dear All,
In Data Type I want the same structure of Idoc as I have imported in the IR. So, do I have to manually create each segment in the Data Type or is there any short-cut to call the same structure of an idoc in the data type.
Warm Regards,
N.Jain

Hi Nishu,
No need to create the DT for IDOC.
you can use the same IDOC structure.
You the export and import xsd options for the IDOC.
Cheers...
Vasu
** REward POints if found useful **

How do I Change the plot waveform colour on a Dynamic Data type Graph?

I have multiple different plots on different graphs, and I want to set the colours of the different waveforms.
In order to display the waveforms on different graphs, I switched to Dynamic data type and then split the wire
according to how many channels I have.
I can set the graph background colour with a property node, and create cursors of different colours no problem
using the array of references that I have created, so there is nothing wrong with my array of references or the property node.
As soon as I try and wire a colour box into the Plot>Plot Colour control, I get error 1055 out of the property node.
I was wondering if it was an error between the keyboard and the chair, but now I am thinking it is someting more sinister.
The Error box pops up and can't be dismissed remaining the focus until I run TASKKILL on LabVIEW and terminate it.
Any ideas on how to achieve my goal would be appreciated.
(LabVIEW 8.6)
Solved!
Go to Solution.

Hi Sheela,
It's 1 plot per graph, up to 4 graphs displayed on different tabs.
Here are some screenshots
Attachments:
graph_display.JPG ‏135 KB
set_Plot_colour.JPG ‏79 KB

How Abstract class differ, When we call class to be Abstract data type?

Similar Messages

Maybe you are looking for