How do I create an object on the fly

Hello there,
I was wondering if it is possible to create an object on-the-fly. For example:- I have a class called Customer which holds the name, address and phone number of a customer. While the program is running I get a new customer, Mr Brown. How can I create a new Customer object which will hold the details of Mr Brown.
yours in anticipation
seaview

If I understood you right, you are thinking far too complicated.
So, when you click a button, a new object shall be created and stored. So basically you write a listener to your button that contains a method like this:
public void actionPerformed(ActionEvent e){
Customer newCustomer = new Customer(textfield.getText());
listOfCustomers.add(newCustomer);
}Maybe what got you confused is the object's name. Remember this: variables and field names DON'T exist anymore at runtime! They are just meant to help you when programming. If you want Mr. Brown as a customer, you have to provide a field in the customer class for the name. If a field is required for the existence of an object, you usually write a custom constructor for it, which accepts an according parameter.

Similar Messages

How can I create a cluster on the fly?

I'm inserting rows in a database table as part of a logging effort for our program. The table in question has a lot of columns, many of which can be null at any particular time. As such, I'd like to decide at run time (as situations warrant) which columns get a value when I add the new row. The columns are of mixed data types... some strings, some floats, some ints, etc.
For example...
On one pass, I'd like to populate columns "temp", "volume", and "weight".
On another pass, I may want to populate columns "temp", "color", and "notes".
I gen the array of column names. That part's easy
How (in the world) do I create the cluster that feeds the DATA input of the "DB Tools Insert Data" VI?
Sometimes I may need an int, a float, and a boolean.
Other times I may need two ints and a string.
Thanks!
Solved!
Go to Solution.

Given this example you could have a table which contains a the timestamp and a record ID. Most databases can assign the key automatically and guarantee it to be unique. You may also store the machine name or other identifying information specific to this entry. However, all columns in this table would be populated in every record. You can then have another table which contains the specific data for that record. This table would have a column which contains the ID from your other table. You can have multiple entries in this table for that specific ID. This table would contain the ID from the other table, a column indicating what the specifc data is (voltage, temperature, pressure, etc.) and then the data itself. If you have different data types you can have a table for each specific data type (string, double, image, etc.). If you have separate tables for the different data types you would need a key/ID for each data value record. The data tables would simply be the ID for the data attribute and the value itself.
So, table one may consist of the following columns: Table1-Key, Timestamp, Test ID
The attributes table would have the following columns: Table1-Key, Record Type, Data-Key
Your Data Tables would have the following columns: Data-Key, Value (You could have multiple Data Tables for each data type.
To get all the data for a specific time you join the results of the queries from the tables for a specific Table1-Key and the corrsponding Data-Keys from the data tables.
If your table currently has dozens of columns but you are only storing a few at a time your are wasting a ton of space for all the empty columns. Some databases are better than others at reducing this waste but link table help you to store only the specific data for a given record and not fill the database with lots of empty records.
Mark Yedinak
"Does anyone know where the love of God goes when the waves turn the minutes to hours?"
Wreck of the Edmund Fitzgerald - Gordon Lightfoot

How to create reports online on the fly using meta-data.

We have dataset and blank report. How can I create report design on the fly ? so that it will able to display report dataset.
Can someone tell me it is possible or not ? or some reference links....

Hello,
This can be certainly done by executing a script written using Report Application Server (RAS) SDK.
Please refer the link : [http://devlibrary.businessobjects.com|http://devlibrary.businessobjects.com] for detailed documentation on the usage of RAS SDK.
Regards,
Chinmay Athavale
Edited by: Chinmay1009 on Jul 27, 2010 3:46 PM

How to create an object within the same class???

hi im just a newbie
i v been always creating an object from the main class..
but how to create an object inside the same class??
i got main and students class
the main got an array
Students[] stu = new Students[]
and i got
stu[i] = new Students(id,name);
i++;
but i wanna do these things inside the Students class..
i tried ..but i got errors.....
how to do this
.

javaexpert, :)
I really have no idea what you are trying to do since you say you've always been creating an object from the main class, yet you always want to create an object inside the same class.
I'll assume that you have an object in the main class that you are trying to access from the Students class.
If you are trying to access objects that are contained within the main class FROM the Students class, then know that there are two ways of doing so, one being static, and the other dynamic (look up definitions if unclear):
1.) make the objects in the main class both static and public and access the the objects using a convention similiar to: Main.object; It's important to note that Main is the name of your main class, and object is a static object. There are better ways of doing this by using gettter/setter methods, but I'll omit that tutorial.
2.) Create a new instance of the main class and access the objects using a similiar fashion: Main myInstance = new Main(); myInstance.myObject;
You should really use getter and setter methods but I'll omit the code. In terms of which approach is better, step one is by far.
I don't mean to be condecending, but you should really brush up on your programming skills before posting to this forum. This is a fundamenetal concept that you will encounter time and time again.

How can I create an element in the model node?

Hi, Experts,
I create a model node that name is containerNode in the contxt. Cadinility is: 1..n
I write the code in the method:
private String getDataForOutputTable( IWDNode wageTypePayslip, IWDNode containerNode ){
     String betrgSumStr = "";
     int index = 0;
     Vector containerVector = new Vector();
     int size = wageTypePayslip.size();
     IWDNodeElement element = containerNode.createElement();// The system report error when I run the application.
     BigDecimal betrgSum = new BigDecimal( 0 );
I try to create a element in the containerNode, But the system report error when I run the application.
java.lang.IllegalArgumentException: model object must not be null
     at com.sap.tc.webdynpro.progmodel.context.ModelNodeElement.<init>(ModelNodeElement.java:66)
     at besuretech.com.wdp.IPrivatePayDataDispView$IOContainerElement.<init>(IPrivatePayDataDispView.java:1537)
     at besuretech.com.wdp.IPrivatePayDataDispView$IContextNode.doCreateElement(IPrivatePayDataDispView.java:88)
     at com.sap.tc.webdynpro.progmodel.context.NodeInfo.createElement(NodeInfo.java:884)
     at com.sap.tc.webdynpro.progmodel.context.Node.createElementInternal(Node.java:1351)
     at com.sap.tc.webdynpro.progmodel.context.Node.createElement(Node.java:1370)
     at besuretech.com.PayDataDispView.getDataForOutputTable(PayDataDispView.java:251)
     at besuretech.com.PayDataDispView.getAllData(PayDataDispView.java:196)
     at besuretech.com.PayDataDispView.onPlugPayListViewIn(PayDataDispView.java:154)
     at besuretech.com.wdp.InternalPayDataDispView.wdInvokeEventHandler(InternalPayDataDispView.java:391)
     at com.sap.tc.webdynpro.progmodel.generation.DelegatingView.invokeEventHandler(DelegatingView.java:87)
     at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.navigate(ClientApplication.java:826)
     at com.sap.tc.webdynpro.clientserver.cal.ClientComponent.navigate(ClientComponent.java:881)
     at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.doNavigation(WindowPhaseModel.java:498)
How can I create an element in the model node ?
Best regards,
tao

Hi,
You need to execute the model before creating the element.
Regards
Ayyapparaj

How can I create a object for a note?

Hi experts,
I need to apply the note 501905 but when I try in the SNOTE transacction I receive this error:
Object REPS Z_MRM_DELETE_PP does not exist; create it
Diagnosis
The SAP Note that you want to implement contains changes to an object that does not yet exist in your system.
SAP Notes contain only changes to objects that already exist. This means that the the system cannot automatically create new objects during the implementation of this SAP Note.
Procedure
1. Cancel the SAP Note implementationl.
2. Create an empty object REPS Z_MRM_DELETE_PP with the corresponding object editor.
3. Restart the SAP Note implementation.
How can I create that Object??
Thanks for the help!

Hi Carlos,
It says that you have to create a new program with a name Z_MRM_DELETE_PP.
Once you create and activate the program you can execute the SAP Note.
All this processure will be written in the SAP Note.
Please Go through the Note using below:
Step1: Use T.code SNOTE.
Step2: Use menu GOTO --> NOTE BROWSER. Provide the Note no and EXECUTE.
Step3: Double click on the displayed line.
Here you will get the information to do before implementing the note.
Go through all the documentation, and once you did all the development given in the note then you can implement the note.
Regards,
Sreekanth.

How do I create an object from a filename?

I'm traversing directories and storing a list of files in a File array. Then I traverse the array looking at the extension of the file. If it is .java then I would like to instantiate it as a class so that I may pass the new object to another function which will examine its methods. I've tried Class.forName(file.getCanonicalPath()) and it throws a ClassNotFound exception. How can I create an object from a valid filename, please?

Rick_Avlonitis wrote:
If it is .java then I would like to </snip>.java files contain source code, they can't be "instantiated". Class.forName() takes a classname as parameter, i.e. "mypackage.MyClass". A class name is not a file name, and it doesn't have an extension. As stated in the other reply, you'll need to have the class on your class path.

How can I write new objects to the existing file with already written objec

Hi,
I've got a problem in my app.
Namely, my app stores data as objects written to the files. Everything is OK, when I write some data (objects of a class defined by me) to the file (by using writeObject method from ObjectOutputStream) and then I'm reading it sequencially by the corresponding readObject method (from ObjectInputStream).
Problems start when I add new objects to the already existing file (to the end of this file). Then, when I'm trying to read newly written data, I get an exception:
java.io.StreamCorruptedException
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
Is there any method to avoid corrupting the stream? Maybe it is a silly problem, but I really can't cope with it! How can I write new objects to the existing file with already written objects?
If anyone of you know something about this issue, please help!
Jai

Here is a piece of sample codes. You can save the bytes read from the object by invoking save(byte[] b), and load the last inserted object by invoking load.
* Created on 2004-12-23
package com.cpic.msgbus.monitor.util.cachequeue;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
* @author elgs This is a very high performance implemention of Cache.
public class StackCache implements Cache
    protected long             seed    = 0;
    protected RandomAccessFile raf;
    protected int              count;
    protected String           cacheDeviceName;
    protected Adapter          adapter;
    protected long             pointer = 0;
    protected File             f;
    public StackCache(String name) throws IOException
        cacheDeviceName = name;
        f = new File(Const.cacheHome + name);
        raf = new RandomAccessFile(f, "rw");
        if (raf.length() == 0)
            raf.writeLong(0L);
     * Whne the cache file is getting large in size and may there be fragments,
     * we should do a shrink.
    public synchronized void shrink() throws IOException
        int BUF = 8192;
        long pointer = getPointer();
        long size = pointer + 4;
        File temp = new File(Const.cacheHome + getCacheDeviceName() + ".shrink");
        FileInputStream in = new FileInputStream(f);
        FileOutputStream out = new FileOutputStream(temp);
        byte[] buf = new byte[BUF];
        long runs = size / BUF;
        int mode = (int) size % BUF;
        for (long l = 0; l < runs; ++l)
            in.read(buf);
            out.write(buf);
        in.read(buf, 0, mode);
        out.write(buf, 0, mode);
        out.flush();
        out.close();
        in.close();
        raf.close();
        f.delete();
        temp.renameTo(f);
        raf = new RandomAccessFile(f, "rw");
    private synchronized long getPointer() throws IOException
        long l = raf.getFilePointer();
        raf.seek(0);
        long pointer = raf.readLong();
        raf.seek(l);
        return pointer < 8 ? 4 : pointer;
     * (non-Javadoc)
     * @see com.cpic.msgbus.monitor.util.cachequeue.Cache#load()
    public synchronized byte[] load() throws IOException
        pointer = getPointer();
        if (pointer < 8)
            return null;
        raf.seek(pointer);
        int length = raf.readInt();
        pointer = pointer - length - 4;
        raf.seek(0);
        raf.writeLong(pointer);
        byte[] b = new byte[length];
        raf.seek(pointer + 4);
        raf.read(b);
        --count;
        return b;
     * (non-Javadoc)
     * @see com.cpic.msgbus.monitor.util.cachequeue.Cache#save(byte[])
    public synchronized void save(byte[] b) throws IOException
        pointer = getPointer();
        int length = b.length;
        pointer += 4;
        raf.seek(pointer);
        raf.write(b);
        raf.writeInt(length);
        pointer = raf.getFilePointer() - 4;
        raf.seek(0);
        raf.writeLong(pointer);
        ++count;
     * (non-Javadoc)
     * @see com.cpic.msgbus.monitor.util.cachequeue.Cache#getCachedObjectsCount()
    public synchronized int getCachedObjectsCount()
        return count;
     * (non-Javadoc)
     * @see com.cpic.msgbus.monitor.util.cachequeue.Cache#getCacheDeviceName()
    public String getCacheDeviceName()
        return cacheDeviceName;
}

How do I create multiple databases on the same ORACLE_HOME

Hi,
I would like to know how can I create 2 databases on the same ORACLE_HOME? Also is it possible to start both databases at the same time?
When I installed oracle,a directory named database has been created under ORACLE_HOME, which contains all initorc1.ora ,etc ?
At this point how do I create another database named orc2 on the same machine?
Thanks in advance.
winnie philip.

Hi,
Set the oracle_sid=db1
Now rename your init.ora to init<oracle_sid>.ora in $oracle_home/dbs directory.
Change the db_name parameter to appropriate name in the init<oracle_sid>.ora file.
Now create the database.
In the same fashion create another database with the new database name and different oracle_sid
Now in order to switch between the databases.
Change the env variable Oracle_Sid to the value of the database which you wanted to start.
Regards
Anand

How do I create a dropdown in the Subject Line field while sending emails.

How do I create a dropdown in the Subject Line field while sending emails as I send more than 300 emails with the same subject line everyday.

Which webmail service do you use, gmail may have problems currently see thread
'' Subject autofill feature stopped working in gmail for new subjects only - and I'm not the only one - help! {[https://support.mozilla.com/en-US/questions/793610 link]]''
For general information see [[form autocomplete]] and [[Form autocomplete entries are not saved ]]

How do I create a folder in the root directory

Hi
How do I create a folder in the root directory?
Once I do that I need to create a note book file in that folder
Any help would be much appreciated
Thanks
Brian

Hi Brian,
Open Macintosh HD in the Finder, then SHIFT+CMD+n
Root Directory is the top level of the drive.

How do I create a fill-in-the-blank forms

How do I create a fill-in-the-blank forms in Pages 5

Pages does not do it like Word, best you can do is tab over a space and leave that space for the user to type into.
Perhaps putting a small label under to indicate what is required.
A fill in the blanks form made in Pages however really defeats the point.
Who out there has Pages, particularly whatever incompatible version you are using?
Pages has trouble opening Pages files thanks to Apple.
Use standard file formats either pdf (created in Pages, turned into a form in Acrobat Pro or their website) or Word .docx.
Peter

How can I create a drawing like the one pictured from a photo?

How can I create a drawing like the one pictured from a photo?

OK, you are getting closer. Now, use your result, and place a Layer above that. Use the Pen Tool to create the "pen strokes" basically tracing over your background image. Then, when you have created each Path (or Sub-Path), choose Stroke Path, with probably the Pencil Tool and a Brush size that is small enough.
Not sure which versions of PS these are good for, but here are some plug-ins, that might be helpful.
AKVIS Sketch
EdgeLine
Sketch Effects
Sketch Master
I see that one of my old favorites, Flaming Pear's India Ink is not around any more.
Good luck,
Hunt

HT5114 How can I create multiple accounts without the necessity to create multiple email addresses? I now have 2 i-phones (mine and my wife's#, 1 i-pad #mine#, 1 i-pad mini #10 year old's#, and 1 I-pod touch #11 year old's). I would like to maintain pur

How can I create multiple accounts without the necessity to create multiple email addresses? I now have 2 i-phones (mine and my wife's), 1 i-pad (mine), 1 i-pad mini (10 year old's), and 1 I-pod touch (11 year old's). I would like to maintain purchase control, but would like to be able to have a separate account ID for each person. Is that possible?

Each email address can only be on one iTunes account, and all purchases are tied to the account that buys them. If you want to have separate iTunes accounts on each then you will need separate email accounts for each iTunes account

How to center a JFrame object on the screen?

Does somebody know how to center a JFrame object on the screen. Please write an example because I'm new with java.
Thank you.

//this will set the size of the frame
frame.setSize(frameWidth,frameHeigth);
//get screen size
Toolkit kit=Toolkit.getDefaultToolkit();
//calculate location for frame
int x=(kit.getScreenSize().width/2)-(frameWidth/2);
int y=(kit.getScreenSize().height/2)-(frameHeigth/2);
//set location of frame at center of screen
frame.setLocation(x,y);

How do I create an object on the fly

Similar Messages

Maybe you are looking for