Is every method of java a Virtual method ?
Hi,
Is every method of java a Virtual method ? Can any methods be overridden ? Is that making use of double pointer ?
Edited by: shyam1 on Sep 22, 2010 10:44 PM
shyam1 wrote:
jverd wrote:
shyam1 wrote:
Hi,
Is every method of java a Virtual method ?Every non-final, non-private, non-static method can be considered "virtual," although Java doesn't use that term as far as I know.
Can any methods be overridden ? Every non-final, non-private, non-static method can be overridden. Any method that is private, static, or final, cannot be.
Is that making use of double pointer ?
And I am telling you that it is not defined and not relevant.
>>
That is not specified, and is an irrelevant implementation detail.i am asking that, to make every method ( non-final, non-private, non-static method) overridable does java is using any concept called double pointer ?
IT. IS. NOT. DEFINED. An implementation is free to do it however it wants.
Why do you care? Why do you think it matters?
Similar Messages
-
Virtual methods- abstract methods
Hi, I need to get this clear in my head.
In C++ you had virtual methods()
If a method was virtual this made the enclosing class abstract.
There is no such thing as abstract methods in C++?
In java, if you have an abstract method your enclosing class becomes abstract.
There is no such thing as a virtual method in java.
is all the above correct?
Thanks ... JHi, I need to get this clear in my head.
In C++ you had virtual methods()
If a method was virtual this made the enclosing class abstract.
There is no such thing as abstract methods in C++?Incorrect.
Abstract methods have no implementation. You can have those in C++. If I remember correctly, they'd look something like this:
public void foo() = 0;
In java, if you have an abstract method your
enclosing class becomes abstract.
There is no such thing as a virtual method in java.Incorrect.
All methods in Java are virtual by default. Every method is fair game to be overridden by a subclass. You mark them with the final keyword to prohibit overriding.
All methods in C++ are final by default. You can't override any method in a subclass unless you mark it with the virtual keyword. (This was keeping the Bjarne's philosophy of "only pay for what you use".)
% -
How to use " toFront() " method in java application and in which package or
How to use " toFront() " method in java application and in which package or class having this toFront() method.if anybody know pl. send example.
The API documentation has a link at the top of every page that says "Index". If you follow that and look for toFront(), you will find it exists in java.awt.Window and javax.swing.JInternalFrame.
To use it in a Java application, create an object x of either of those two classes and write "x.toFront();". -
JavaScript calls method on Java Applet-- Problem
Hi all,
I have a problem as following:
I have a method on JavaScript calling a method on Java Applet. A method on JavaScript repeatedly retrieves data form the server , let's say; every 100 ms and it calls the method on Java to draw a graph(I use thread to call repaint()). The problem is, if I leave the applet site(or the site has lost the focus), the stop() will be called and I can't recieve data from JavaScript anymore. If I go back to the site, the applet starts, but the graph doesn't show the figure, as it supposes to show.
how can I tell the browser doesn't call the stop() or there is another way to solve this problem?
Thanks for all answers. CU.
A-Pexmy own fault.. it's not the browser or the applet.. It's my computer.. it's too old for this applet..
Does anyone know, how to optimize the applet with thread? thanks.. -
Is there a method in java that can schedule work??
I'm working on a project and I need to start a program at a fixed time each day.
E.g. every day at 03:00 AM!
Is there such a method in java?? Or can somebody give me an
example of how this can be done!
Thank you in advance : )it really depends on whether you mean you want the operating system to start the "program" for you, or whether you want your own java program to spawn other tasks...
Check the OS docs if it is the former, and use java.util.TimerTask for the latter -
Error while opening a dwg file :java.lang.NoSuchMethodException: Method
Hello Experts,
I tried to integrate WebCenter Content with Autovue ,the integration was good untill i get this error while trying to open a dwg file checked in Content Server using View in Autovue option in Actions :
java.lang.NoSuchMethodException: Method fileOpen(com.cimmetry.core.SessionID, com.cimmetry.core.DocID, com.cimmetry.core.Authorization, <null>, java.lang.Boolean, <null>) not found in class com.cimmetry.jvueserver.VCETConnection
at com.cimmetry.jvueserver.ar.a(Unknown Source)
at com.cimmetry.jvueserver.ar.a(Unknown Source)
at com.cimmetry.jvueserver.ar.a(Unknown Source)
at com.cimmetry.jvueserver.ar.d(Unknown Source)
at com.cimmetry.jvueserver.ar.a(Unknown Source)
at com.cimmetry.jvueserver.ah.run(Unknown Source)
Any suggestions would help me,
Thanks in Advance
RajHi Raj,
The solution to this problem is posted in My Oracle Support:
Error: "java.lang.NoSuchMethodException: Method fileOpen" when Trying to View Files Using AutoVue Integrated to Oracle Universal Content Management (UCM) (Doc ID 1341644.1).
It has all the details, step by step.
Jeff -
How to call the java method in java script function in a portal application
Hi Friends,
I am developing one application where i need to fetch the data from KM content and displaying it on the screen in regular interval. I wrote one method in JSPdynpage for fetching data from KM content now I need to call that java method in java script function.
java method(IComponentRequest request)
//Coode for fetching the KM content
function()
<b>//Need to call the java method</b>
setTimeout(function, 5000);//setting the time interval for this function
<<htmlb display code>>
If anybody can help me in calling the java method in java script function that will be very helpful for me.
Thanks in advance,
Sandeep BonamHi,
Pls see if the following links could help.
http://www.rgagnon.com/javadetails/java-0170.html
http://www-128.ibm.com/developerworks/library/wa-resc/?dwzone=web
Regards -
Hi ,
oracle apps version : 11.5.10.2 and database version 11.2.0.2.
OS version Solaris Sparc 64 Bit.
We were performing a cloing activity on a new server and now while opening forms we are getting the following error :
error:java.lang.Double:method parseDouble(Ljava/lang/String;)D not found.Please suggest what has to be done.
Regards
KkHi ,
D:\Documents and Settings\800045916>java -version
java version "1.6.0_29"
Java(TM) SE Runtime Environment (build 1.6.0_29-b11)
Java HotSpot(TM) Client VM (build 20.4-b02, mixed mode, sharing)We have been struggling with the Solaris server for this. Is something needed from there also or just need to have the latest JRE in the windows client machine.
Regards
Kk -
No getting Report Output in OAF for java Concurrent program Method
I am not getting report output for java Concurrent Program(Concurrent Program Executable Method), for the reports which are of type PL/SQL Stored Procedure getting the output. for some of the reports the executable method is 'java Concurrent Program', so is there any thing i need to modify in my code.
Thanks
BabuThe Concurrent request is not able to generate output
getting following error in FNDCPREQUESTVIEWPAGE
The concurrent request 9923758 did not create an output file.
so what may be reasons for this?
Thanks
Babu -
Hi , when i try to run my program, i keep getting the error msg:
Error(23,19): method getName(java.lang.String) not found in class javax.swing.JTextField
I have checked the java API and it inherits from the awt.Component class and should be accessible via the jtextfield.
I have tried the following:
trying to initailise the JTextField at the start.
Using getName works if i use it within the loop after setting the name.
Does anybody know what i am doing wrong please?
public class clsMember extends JPanel implements ActionListener {
private JButton jbtnLog;
private String surname;
private JTextField txtItem;
public clsMember() {
super(new SpringLayout());
makeInterface();
surname = txtItem.getName("Surname").toString();
private void makeInterface() {
//code omitted
for (int i = 0; i < numpairs; i++) {
JLabel l = new JLabel(strLabels, JLabel.LEADING);
this.add(l);
//if the array item is salutation create a combobox
if (strLabels[i] == "Salutation") {
jcomSalutation = new JComboBox(strSalutation);
jcomSalutation.setSelectedIndex(0);
this.add(jcomSalutation);
} else {
txtItem = new JTextField(10);
l.setLabelFor(txtItem);
txtItem.setName(strLabels[i].replaceAll(" ", "")); //this is where the label is set and if i do a system.out it shows fine. getName works here too.
this.add(txtItem);
//code omittedIf i have a loop that creates the jtextfields such as
txtItem = new JTextField(10);
l.setLabelFor(txtItem);
txtItem.setName(strLabels.replaceAll(" ", ""));
this.add(txtItem);How is it then possible to assign to a string the value of a *specific jtextfield*. Lets say that one of these JTextfields has the name surname.
How is it possible for me to writeString surname = surnamejtextfield.getText(); -
Deprecated methods in java.lang.thread
Hi,
I am getting the followng warning message when i run my code:
The method void stop() in class java.lang.Thread has been deprecated,
can anyone suggest an alternative method to the deprectaed stop method, i can't seem to find one.
Thanks in advanceThe stop() method in thread has been deprecated because it is inherently dangerous. The suggested action now is to simply modify a variable inside the thread to tell it to stop running, and the thread should periodically check the variable to see when it should stop. There's good description of why stop() and a few other methods in Thread have been deprecated at..
http://java.sun.com/j2se/1.4/docs/guide/misc/threadPrimitiveDeprecation.html -
Java.sql.Blob method setBinaryStream?
Hi,
I've been trying to use the java.sql.Blob methods instead of the "Oracle Extensions" so that people w/o Oracle (using MySQL etc.) can still use my code.
Problem: trying to get the OutputStream to write to the Blob. As of JDK1.4, java.sql.Blob has a method to do this, setBinaryStream. Unfortunately, calling this in Oracle JDBC (tried it in both thin and OCI version) throws an SQLException (Unsupported feature).
Sample code:
//Assume we already have a connection to the database, over either OCI or thin.
//Assume a Statement stmt created from the connection.
//Assume a table BlobTable with 2 fields : id (number) and data (blob).
public void uploadBlob(byte [] theBytes){
try{
stmt.executeUpdate("INSERT INTO BlobTable (id, data) VALUES (1,empty_blob())");
ResultSet rs = stmt.executeQuery("SELECT data FROM BlobTable WHERE id=1 FOR UPDATE");
if (rs.next()){
java.sql.Blob blob=rs.getBlob(1);
OutputStream out=blob.setBinaryStream(0);
//Next line never printed - error thrown.
System.out.println("Got Stream");
catch(Exception e){e.printStackTrace();}
//End code
Am I doing something wrong? Or is there simply no way to write to a Blob without using the extensions?
None of the docs (examples, guides, etc) make any mention of this, although the JDBC dev guide does mention that the similar method in PreparedStmt only works over OCI.
Thanks,
DanHi lancea,
It's been a while since this thread was active, but I have a related question.
Is there a comprehensive list of changes between JDBC 3 and JDBC 4 that makes application not work any more, such as this setBinaryStream issue or the CallableStatement/Named parameters issue that we stumbled upon. We would like to address these issues proactively and not find out about them in production, since we're upgrading from jdk1.4 to jdk6. Oracle has provided us with their changes regarding database versions, but have been less forthcoming with JDBC spec version changes.
Thanks in advance,
Thomas Auzinger -
Accesing database from static method on java collaboration
Hi *,
I want cache data from a oracle database in a java collaboratioon when java collaboration is enabled by emanager.
My java collaboration has a oracleOTD
I did an static method on java collaboration, but I can't access database from static method.
Thanks
Hectorhi hector,
this wont work!
regards chris -
java.lang.NoSuchMethodError: java.lang.Float: method parseFloat(Ljava/lang/String;)F not found
WHAT WOULD MAKE THIS HAPPEN. THIS SEEMS TO WORK IN JDK1.3.1 BUT NOT IN BLACKDOWN 1.1.3_V3
THIS IS MY CODE:
try{
DecimalFormat dfp = new DecimalFormat( "0.00" );
if(!Price.equals("")) {
float MyFloat = Float.parseFloat(Price);
Price = dfp.format(MyFloat);
}catch(NumberFormatException nfe){
PriceValid = 1;This error says:
- There is no method called "parseFloat" that receives a String as parameter in class java.lang.Float.
Look the method "parseFloat" at the class java.lang.Float!! -
Problem in addBatch method in java.sql.Statement Interface
Hi
I am facing a problem java.lang.UnsupportedOperationException when using addbatch() method of java.sql.Statement Interface.
Please suggest solutions.
Thanks
nsgindiaYour JDBC driver doesn't support batch operation, try another driver(not all databases support batch'es eg MySQL)
Maybe you are looking for
-
How to Create Check Box in Dynamic Table
Hi Friends, I've Created one Dynamic Table there i want to display 2 columns as Check Box. How to Add this check box as column cell variant. Looping the columns. In this One method SET_TABLE_CELL_EDITOR is ter. But i'm getting how to use this method.
-
How to dual boot with Windows 8.1 and Arch?
Hello everyone, I've been looking into using Linux as my daily driver since having some experience with it on a server. After some digging around, I think Arch Linux is the best distro for me, now onto where I am. I'm currently running Windows 8.1 (u
-
Newbie Question On Library Creation and File Duplication
I'm new to iTune's hard drive file organizing structure, so bare with me. I have a single directory on Hard Drive 2 (HD2) called "Music". When I create a music library in iTunes from that music directory source, iTunes appears to create its own new d
-
Function of 'Declare' in Stored Procedure statements
Dear Readers, Can someone tell me what is the difference when we use Declare and don't use declare in the create stored procedure statement. Please see below: Create proc education AS Declare @name varchar(20) Select @name='John' GO When I run this
-
Hello All, I recently joined in phase two of an HR implementation for a client of ours. I am tasked with the implementation and configuration of XSS. I am facing an issue concerning creating a relationship between a user and an employee. Apparently t