Creating a dynamic Array

Thanks for reply.
I want to create a dynamic array and for this I used ArrayList Collection and Vector Class. I am using JDK 1.4.1 . But , I have a problem in that. In ArrayList, I used the following code:
ArrayList al = new ArrayList();
while(rs.next())
al.add(rs.getString("Enter_Year"));
al.add(rs.getString("UG_Production_Mi_Te"));
al.add(rs.getString("OC_Production_Mi_Te"));
al.add(rs.getString("Total_Production_Mi_Te"));
al.add(rs.getString("OBR_MM3"));
al.add(rs.getString("OMS_Te"));
al.add(rs.getString("Coal_Offtake_Mi_Te"));
al.add(rs.getString("Supply_to_Steel_Plant_Th_Te"));
al.add(rs.getString("Royalty_SalesTax_MP_Crs"));
al.add(rs.getString("Royalty_SalesTax_CG_Crs"));
al.add(rs.getString("Total_ManPower"));
al.add(rs.getString("Fatality_Rate_per_Mi_Te_Output"));
al.add(rs.getString("Total_Wellfare_Expenditure_Crs"));
String rpt[][] = new String[al.size()][];
rpt = al.toArray(rpt); // ArrayStoreExecption error
String colheads[] = {"...........My Table's Column names are here....."};
JTable table = new JTable(rpt,colheads);
JScrollPane jsp = new JScrollPane(table);
add(jsp);
At the statement having comment line I received the error ArrayStoreException. The JTable accepts the 2 D array for storing the info and I think the toArray() method is not working there and can't convert the ArrayList elements into an Array. Similarily, Vector Class is also not converting the elements into an array object and showing the same error only.
Please help me to convert it into an array object so that I can pass it into the JTable argument.

That isn't a jdbc problem but rather a collection problem.
You certainly can't convert a one dimensional collection into a two dimensional array automatically. And that is what you are creating with the while loop.
Since you know the column names you also know the inner array size so you can start by creating a statically sized string array (not collection) in the loop and add that to the outer collection. That might solve the problem.

Similar Messages

Creating a dynamic array in Actionscript

I am wondering how I would create a dynamic array in Acionscript, i.e. one that utilizes fields for mapping data like this:
public var SMITH:Array = [
           {date:"29-Aug-05", close:45.87, profit:52},
           {date:"23-Aug-05", close:45.74, profit:32},
           {date:"21-Aug-05", close:45.77, profit:22},
           {date:"25-Aug-05", close:46.06, profit:51},
but where you would just be reading in data without knowing what your data looks like. In other words, I'd like to take something like a database table with X number of columns and have Actionsctipt map each row to an item in my array. Something like this:
for each row in table
add {col1:value, col2:value, col3:value, ... colX:value} to Array
So I won't know "date" or "close" or whatever at runtime, I'll just have X number of items for each element in the array. How would this be done?
The reason I need this mapping feature is because I then want to map the table-like array as the data provider to charts, datagrids, etc.
Thanks.

If this post answers your question or helps, please mark it as such.
You can download the lib for JSON in Flex here:
http://code.google.com/p/as3corelib/downloads/list
These pages describe using JSON and Flex, and databases:
http://www.switchonthecode.com/tutorials/flex-php-tutorial-transmitting-data-using-json
http://www.switchonthecode.com/tutorials/using-flex-php-and-json-to-modify-a-mysql-databas e
http://www.switchonthecode.com/tutorials/flex-php-json-mysql-advanced-updating
http://www.mikechambers.com/blog/2006/03/28/tutorial-using-json-with-flex-2-and-actionscri pt-3/

Creating dynamic array

Can anybody tell me how to create a dynamic array in Java??I dont want to fix size of array,it should take any number of values at runtime.Please tell me the syntax of using dynamic arrays.

Hi,
For creating an array of similar data elements, use
ArrayList., but for storing elements which are in the
form of object then use Vector...
Best of Luck..
R SWrong... the main different between ArrayList and Vector is that Vector was sychronized and ArrayList are not.

Creating a dynamic Integer Array

Hi there.
This may seem trivial, but how do I create a dynamic array to store integers?
I tried Integer integerArray [] = new Integer (); but i get Cannot Resolve Symbol Error.
I am using Java 1.4.2 version.
Any suggestions would be helpful. Thanks

Doesnt an ArrayList store values as
String? Even if i did use Integer.parseInt to cast to
Integer from String doesnt it become tricky if i have
to do much calculations?Hi,
An ArrrayList can store any object you wish not just String. All you need to specify when retrieving an object is the type of object you want.
For example, if you have an ArrayList of integers an you want to retrieve an integer from the list you would use:-
int myInt = (int)myArrayList.get(myIndex);Therefore if you want to store an arbitrary object foo in an ArrayList the code is thus:-
//replace foo with the object you are storing.
foo foobar = (foo)myArrayList.get(myIndex);There is a slight change with ArrayLists in Java 5 where you should declare the objects that should be stored in the list but hopefully the above helps you to understand that an ArrayList or any other Collection as it happens can store objects of your choosing.
Regards,
Chris

Store int values into dynamic array

Hello all,
I'm a newbie in JAVA whose want to store int values (coming from a resultset) into an dynamic array. I know that normally to create a "dynamic array" you'd better use a Vector, but it seems that I don't know how to use it correctly (throws me a exception as : Incompatible type for method. Can't convert int[] to java.lang.Object[]).
Thanks in advance
STF

I want to use the copyInto method of the vector, but it throw me an exception as ')' expected
I include a snip of my code below ;
Vector v= new Vector();
Vector vv=new Vector();
String[] labels=new String[v.size()];
Integer[] values=new Integer[vv.size()];
cont=rs.getInt("COUNT(CASE_ID_)");
vv.add(j,new Integer(cont));
log=rs.getString("ORIG_SUBMITTER");
v.add(j,new String(log));
v.copyInto(String[] labels);
vv.copyInto(Integer[] values);

How to create an new array from dynamically discovered type

    public static Object toAdjustedArray(Object source, Object addition,
                                         int colindex, int adjust) {
        int newsize = 0;
        Class componentType = null;
        if (source.getClass().isArray()) {
            Object[] arrayIn= (Object[])source;
            componentType = arrayIn[0].getClass();
            newsize = arrayIn.length + adjust;
        else {
            System.out.println("error in ArrayUtil");
        Object[] newarray = new Object[newsize];
        copyAdjustArray(source, newarray, addition, colindex, adjust);
        return newarray;
    }This methods take an array as an input an append new value(s) to it.
I can get the component type of the array (i.e. the class of the array's member). But how can I create a new array of this component type (i.e doing something like componentType[] newarray = new componentType[newsize])?
CU Jerome

I fanally found a walkaround trick for my problem.
Their is no way to create an array of a certain type (dynamically dsicovered) in CLDC. But what you can do is to use the instanceof method to determine the type of your array and in a big if statement create the right array.
Here is the final code:
    public static Object toAdjustedArray(Object source, Object addition,
                                         int colindex, int adjust) {
        int newsize = 0;
        if (source.getClass().isArray()){
            Object[] arrayIn= (Object[])source;
            newsize = arrayIn.length + adjust;
        Object arrayElement = null;
        if (addition.getClass().isArray()){
            Object[] temp = (Object[])addition;
            arrayElement = temp[0];
        else{
            arrayElement = addition;
        Object newarray = null;
        if (arrayElement == null){
            newarray = new Object[newsize];
        if (arrayElement instanceof org.hsqldb.Index){
            newarray = new org.hsqldb.Index[newsize];
        else {
            newarray = new Object[newsize];
        copyAdjustArray(source, newarray, addition, colindex, adjust);
        return newarray;
    }

Creating a byte Array dynamically.Urgent Help needed.

Hi there,
I need to create a byte Array with the values
derived from the array and then am passing this byte array
to a method.
Example :
public static void main(String[] args) throws IOException {
char chars[] = {'a','j','a','y'};
byte[] b = {
(byte) chars[0],(byte) chars[1],(byte) chars[2],(byte) chars[3],
//** Send name to a server.
sendRequest(b);
This is all right.
But here I know the size of the character array chars.
If it had more than 4 characters or less than 4,
is there a way to create the byte array dynamically based on the values in the character array?
Please can some one help me with creating a byte array on the fly?
Has anyone understood my question please?
A response is much much appreciated.

The actual problem is this.
The byte array already has some fixed values to it
and i need to append the values of the character array
to this byte array
ie
char chars[] = {'a','j','a','y'};
byte b[] = {
// Predefined values
(byte) 0x01, (byte) 0x7E, (byte)0x03
// I have to add the values from the array here
(byte) chars[0], (byte) chars[1]....
How can I add these values.? The size of the character array
can vary

Creating a byte Array dynamically.An Urgent Request.

Hi there,
I need to create a byte Array with the values
derived from the array and then am passing this byte array
to a method.
Example :
public static void main(String[] args) throws IOException {
char chars[] = {'a','j','a','y'};
byte[] b = {
(byte) chars[0],(byte) chars[1],(byte) chars[2],(byte) chars[3],
//** Send name to a server.
sendRequest(b);
This is all right.
But here I know the size of the character array chars.
If it had more than 4 characters or less than 4,
is there a way to create the byte array dynamically based on the values in the character array?
Please can some one help me with creating a byte array on the fly?
Has anyone understood my question please?

Well, if you have the byte array already, you're probably going to have to either make the original array large enough to hold whatever you would put into it or create a new array when you know what you are going to add.
This seems pretty simple, so maybe I'm missing the point. But...
char chars[] = { ... };
byte bytes[] = new byte[<some other size> + chars.length];
for (int i = 0; i < chars.length; i++)
bytes[i + <offset>] = (byte)chars;
If you can't effectively figure out a static size for this array and you have to copy contents, look at System.arrayCopy() to possibly improve performance of the copy.

Can I create a dynamic number of inputs during runtime?

Can I create a dynamic number of inputs during runtime?
Oracle 11g
Application Express 4.0.2.00.06
Here is my problem:
We have a table that holds metadata about files (hardcopy or softcopy files).
We expect we may need more columns in the table at some point and don't want to modify the table or the application.
So in order to do this I would like to create:
A table called TBL_FILE with the columns:
TBL_FILE_ID               NUMBER                (This will be the primary key)
TBL_FILE_NAME          VARCHAR2(1000) (This will be the name of the file)
A second table will be called TBL_FILE_META with the columns:
TBL_META_ID               NUMBER               (This will be the primary key)
TBL_FILE_ID               NUMBER                (This will be the forign key to the file table)
TBL_META_COLUMN     VARCHAR2(30)     (This is what the column name would be if it existed in TBL_FILE)
TBL_META_VALUE          VARCHAR2(1000) (This is the value that record and the 'would be' column)
So a person can have as much meta data on the file with out having to add columns to the table.
The problem is how can I allow users to add as much data as they like with out having to re develop the page.
Other things to note is that we would like this to be on a single page.
I know how to add we can create multi-row inserts by using a SQL Query (updateable report),
however the TBL_META_VALUE column in the TBL_FILE_META will sometimes be a select list and other times a text box or number field.
So I don't see now a SQL Query (updateable report) would work for this and I can't create an array of page items at run time can I?
Any idea's how I could accomplish this? Is there a better way of doing this?
Also is there a term or a name for what I am doing by creating these 'virtual' columns in another table?
I found this method when looking at Oracles Workflow tables.

Welcome to the Oracle Forums !
>
Can I create a dynamic number of inputs during runtime?
Oracle 11g
Application Express 4.0.2.00.06
Here is my problem:
We have a table that holds metadata about files (hardcopy or softcopy files).
We expect we may need more columns in the table at some point and don't want to modify the table or the application.
So in order to do this I would like to create:
A table called TBL_FILE with the columns:
TBL_FILE_ID NUMBER (This will be the primary key)
TBL_FILE_NAME VARCHAR2(1000) (This will be the name of the file)
A second table will be called TBL_FILE_META with the columns:
TBL_META_ID NUMBER (This will be the primary key)
TBL_FILE_ID NUMBER (This will be the forign key to the file table)
TBL_META_COLUMN VARCHAR2(30) (This is what the column name would be if it existed in TBL_FILE)
TBL_META_VALUE VARCHAR2(1000) (This is the value that record and the 'would be' column)
So a person can have as much meta data on the file with out having to add columns to the table.
The problem is how can I allow users to add as much data as they like with out having to re develop the page.
>
Creating Page Items dynamically is not available. You will have to create excess items and hide/show , etc. But you cannot change the Item Type. All in all, too many limitations in this approach.
>
Other things to note is that we would like this to be on a single page.
>
The 100 item limit will hit you if you go with extra item on page. With Tabular Form that should not be a limitation, unless you are exceeding the 50 item limit of APEX_APPLICATION.G_Fnn items, and the 60 column limitation of Report region with "Use Generic Column Names (parse query at runtime only)" of Dynamic region.
>
I know how to add we can create multi-row inserts by using a SQL Query (updateable report),
however the TBL_META_VALUE column in the TBL_FILE_META will sometimes be a select list and other times a text box or number field.
>
If the type if item is variable it only means you need a way to store the item type. Meta Data of the Meta Data.
>
So I don't see now a SQL Query (updateable report) would work for this and I can't create an array of page items at run time can I?
>
Yes, you can do it. Updatable report/ Tabular Form query can be constructed from the Meta Data using PL/SQL Function Returning SQL Query . It will be a bit of coding in PL/SQL where you use the Meta Data and the Meta Data of the Meta Data to piece together your SELECT with the right APEX_ITEMs. It might have a performance penalty associated with it, but will not be a serious degradation.
>
Any idea's how I could accomplish this? Is there a better way of doing this?
Also is there a term or a name for what I am doing by creating these 'virtual' columns in another table?
I found this method when looking at Oracles Workflow tables.
>
I guess that is just a good TNF. It is the Master-Detail Design Pattern, that sound more modern ? ;)
Regards,

Populating a dynamic array with objects and managing it in runtime.

So I'm another stuck firstyear. I'll try and make my question compact. I'm using Flash CS6 and have drawn an animated character on the stage that consists of separate parts that are animated and its head is a separate class/symbol entirely because it has not only animation, but a state switch timeline as well. This said Head extends the Main that is the character MovieClip.
I am using a dynamic array to store and .push and .splice objects of another class that would collide with this said Head.
I also discovered the super() function that is implicitly called as the constructor of the parent in any child class that extends the parent, in this case Head extends Main. The issue is that my collidable object array is populated within the main, within the function that spawns every next collidable object with a TimerEvent. This said function then gets called twice due to the super() call.
I have tried putting this super() call into an impossible statement in my child class, but it doesn't change a thing, and it was said that this method is unsafe so I don't even know if it should be working.
However what confuses me the most is when I trace() the .length of my collidable object array at the end of that function. As I said earlier, the original function both spawns an object after a period of Timer(1000) and adds it to the stage as well as adds the object onto the object array, but the super() constructor only duplicates the length call and a creates a copy of the object on the stage, but it does not add the second copy of the object onto the array. The trace() output goes on like so:
1
1
2
2
3
3
4
4
etc.
I wonder why and I'm really stumped by this.
Here is the code in question:
public class Main extends MovieClip {
                    public var nicesnowflake: fallingsnow;
                    var nicesnowflakespawntimer: Timer = new Timer(1000);
                    public var nicesnowflakearray: Array = new Array();
                    public function Main() {
                              nicesnowflakespawntimer.addEventListener(TimerEvent.TIMER, nicesnowflakespawn);
                              nicesnowflakespawntimer.start();
                    public function nicesnowflakespawn(event:TimerEvent) : void {
                              nicesnowflake = new fallingsnow;
                              nicesnowflake.x = Math.random()* stage.stageWidth;
                              nicesnowflake.y = - stage.stageHeight + 100;
                              nicesnowflakearray.push(nicesnowflake);
                              stage.addChild(nicesnowflake);
                              trace(nicesnowflakearray.length);
                              for (var i:Number = 0; i < nicesnowflakearray.length; i++){
                                        nicesnowflakearray[i].addEventListener(Event.ENTER_FRAME, snowhit);
                    public function snowhit(event:Event) : void {
                              if (nicesnowflakearray[0].y >= 460){
                                        if (nicesnowflakearray[0].y == stage.stageHeight) {
                                        nicesnowflakearray.splice(nicesnowflakearray.indexOf(nicesnowflake), 1);
                              //if (this.hitTestObject(nicesnowflake)){
                                        //trace("hit");
I am also fiddling with the collision, but I believe that it would sort itself out when I deal with the array pop and depop properly. However I'm pasting it anyway in case the issue is subtly hidden somewhere I'm not looking for it. And here is the child class:
public class Head extends Main {
                    public function Head(){
                              if (false){
                                        super();
                              this.stop();
So like what happens at the moment is that the array gets populated by the first object that spawns, but there is two objects on the stage, then when the objects reach stage.460y mark the array splices() the one object away and displays an error:
"#1010: A term is undefined and has no properties.
          at Main/snowhit()"
then when the next object spawns, it repeats the process. Why does it trace the array.length as "1, 1, 2, 2, 3, 3, 4, 4, 5, 5, etc" until the despawn point and then goes on to display an error and then starts from 1 again, because if the array length is more than one object at the time when the first object of the array gets spliced away, shouldn't it go on as usual, since there are other objects in the array?
Thank you very much to whomever will read this through.

There are multiple problems:
1. You should add eventlisteners for your objects only once, but you add eventlisteners every time your timer runs to all of your snowflakes, again and again:
                              for (var i:Number = 0; i < nicesnowflakearray.length; i++){
                                        nicesnowflakearray[i].addEventListener(Event.ENTER_FRAME, snowhit);
change it to
nicesnowflake.addEventListener(Event.ENTER_FRAME, snowhit);
I don`t see why its even necessary to employ this snowflakearray, it would be much straight forward if you simply let the snowflakes take care of themselves.
2. Then you have to change your enterframe function accordingly
public function snowhit(event:Event) : void {
                              if (e.currentTarget.y >= 460){
                                        if (e.currentTarget.y == stage.stageHeight) {
                                        e.currentTarget.removeEventlistener(Event.ENTER_FRAME, snowhit);
                                        removeChild(e.currentTarget);
3.
                              //if (this.hitTestObject(nicesnowflake)){
                                        //trace("hit");
since "this" is a reference to the Main class (root) it surely won`t function as you intend it to.
                              if (false){
                                        super();
makes no sense to use a condition that can never be true

How do I create a Dynamic java.sql.Date ArrayList or Collection?

I Have a MySQL table with a Datetime field with many values inserted.
I want to know which is the Best way to capture all the Inserted DB values inside a Dynamic Array.
I get errors that state that I should use Matching data-types, and plus I don't know how to create or fill a Dynamic Date ArrayList/Collection.
Please Help, I need this urgently...

package pruebadedates;
import java.sql.*;
* @author J?s?
public class ClaseDeDates {
    /** Creates a new instance of ClaseDeDates */
     * @param args the command line arguments
    public static void main(String[] args) {
        java.sql.Date aDate[] = null;
        Connection con = null;
        Statement stmt = null;
        ResultSet rs = null;
        try{
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            con = DriverManager.getConnection("jdbc:mysql://localhost/pruebafechas", "root", "picardias");
                if(!con.isClosed()){
                stmt = con.createStatement();
                stmt.executeQuery ("SELECT dates FROM datestable");
                rs = stmt.getResultSet();
                    while (rs.next())
                    aDate[] = rs.getDate("dates");
        catch(Exception e)
           System.out.println(e);
        //System.out.println(aDate);
}Hi, There is my code and the errors that I get are:
found : java.sql.Date
required: java.sql.Date[]
aDate = rs.getDate("dates");
Actually I have No idea as How to get a Result set into an ArrayList or Collection. Please tell me how to do this Dynamically. I have like 25 records in that Database table, but they will grow, so I would really appreciate to know the code to do this. I suspect my problem is in the bolded part of my code.
Thank you very much Sir.

Dynamic array gen....

Hello All,
We are facing some problem regarding generating array dynamically.
Is it possible to generate array dynamically within program in java.
We want to genrate an array, of type byte as shown below.
byte datafile1[],datafile2[],datafile3[],datafile4[]; etc.,
We want to decleare and initalize these arrays dynamically within the program(not manually).
Hope you all understand my problem.
Help me to solve this problem as soon as posible.
Its urgent for me.
Thankyou,
RajivChowdary.

Either use an array-like object, such as an instance of any List types (Vector or ArrayList, for instance) as they will dynamically resize when you add or remove elements from them, or create a method to "resize" your array at runtime. Since arrays cannot be resized per se, simply create a new array of the size that you'd like, and copy the contents of the old one into it using System.arrayCopy(). I'd personally go for the List object.

Is it possible to create controls dynamically.

Hai,
Is it possible to create control or arrays dynamically in LabVIEW.That means i want to create controls at run time depending on the dynamic data.
Please help me in this regard.

Ben wrote:
Christian's "Create Controls on the Fly"
Just for reference, Here's the original fly post. Makes it easier to find my old stuff.
(Of course there could be other interpretations of "on the fly": The 1971 album cover of "Sticky Fingers" but the Rolling stones comes to mind. )
LabVIEW Champion . Do more with less code and in less time .

My stupid FOR loop doesnt work to create a new array, help!

Hello, I need help creating a new integer array that contains exactly one of each element a different array.
My original array is called co[]
lets say it has the values: 1213445232
I want my new array called classArr[]
for example, it would end up being: 12345
my integer array is called classArr[]. and i want it to store exactly one of each element from the co[] array. Here is my code. It compiles without errors, but I get out of bounds exception when i run it.
classArr[0] = co[0];
int temp = 1;
for (int k = 0; k < x; k++) { //x is the number or elements in co[]
     for (int j = 0; j < temp; j++) {
          if (classArr[j] != co[k]){
                classArr[temp] = co[k];
                temp++;
System.out.println("Values in new array");
for (int c = 0; c < temp; c++){
     System.out.println(classArr[c] + " ");
} Thanks for your help!!!!

im pretty sure the initialization of the variables are
set right.Well, without seeing the initialization I doubt I can help you. Try to figure out if it is classArr[temp] or co[k] that causes the exception. (Hint: put them on two different lines.)
x is the number of elments in the co[] arrayTry replacing it with co.length.
classArr[] is a dynamic array set to a number, lets
say it's abcWhat is a "dynamic array" in your terminology? And what is "abc"? Please provide at least the declarations of your arrays.

Dynamic arrays

Hi all,
I am controlling a two level stepper motor via a USB 6009. I created the pulses using software timing by setting an array of elements to change between 0 and 5 V continuously as shown in the attachement. The probelm now is that i want to be able to control the number of degrees that the motor moves by so say 1 degree = 35 elements in the array. How do I do that using dynamic arrays? i'd like to be able to specify the number of degrees and hence the number of elements in the array of values 0 and 5. I am completely new to labView so any ideas or examples will be great.
Thank you
Myriam
Attachments:
PulseMotSelect.vi ‏79 KB

Thank you very much for your prompt answer. I thought the built in signal generation functions require a clock and the USB does not have a clock on it. That is why I am using software timing. If it is still possibel to use the buillt in signal generation functions then where do i get them from on Labview if i want to create a square pulse? and yes i did create them all by hand becuase i didnt know where these functions are and if they would work with USB 6009 without the clock.
With the code that I have sent you, the motor moves continuously once the usb is connected. The only way i can stop it is if i unplug the USB. What i want to be able to do is to be able to conrol the motor so that it stops after a certain number of degrees specified by the user. This is what i wanted the dynamic array for. Another way that i thought of for doing that is using a timed loop to control the motor motion instead. So say it takes 1 sec to move 1 degree then 30 secs to move one degree and use that to control the degree of motion rather than the elements in the array. Would that still work? if not then how can i modify the array to do that? as it moves continuously with 1500 elements so how can i limit when it stops?
Sorry if my problem is too complicated but i am new to labview so any help is welcome.
Thank you in advnace for your help
Myriam

Creating a dynamic Array

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