Multiple constructors for methods

I have to write a method that takes both ArrayList and array so i'm assuming that i'll need something like multiple constructors for classes but i can't seem to find anything about this anywhere. Is it possible?

Uhm, then you don't need multiple constructors, just overload your method.
[http://java.sun.com/docs/books/tutorial/java/javaOO/methods.html]

Similar Messages

Multiple constructors for BPM Object

I need to create BPM object which can have more than one (overloaded) constructors.
Somehow I am not able to find out a way to create new constructor for a BPM object in Studio.
I guess if I create a Java class and import it in the project, it may work, but I would prefer to create a BPM object rather than java code so that I can easily modify the code as and when required.
Can someone help?

Hi,
Sorry - there's no way to create multiple constructors for a BPM Object (unless as you mentioned - you create an hier from a Java jar file).
Dan

Finalize() method being called multiple times for same object?

I got a dilly of a pickle here.
Looks like according to the Tomcat output log file that the finalize method of class User is being called MANY more times than is being constructed.
Here is the User class:
package com.db.multi;
import java.io.*;
import com.db.ui.*;
import java.util.*;
* @author DBriscoe
public class User implements Serializable {
    private String userName = null;
    private int score = 0;
    private SocketImage img = null;
    private boolean gflag = false;
    private Calendar timeStamp = Calendar.getInstance();
    private static int counter = 0;
    /** Creates a new instance of User */
    public User() { counter++;
    public User(String userName) {
        this.userName = userName;
        counter++;
    public void setGflag(boolean gflag) {
        this.gflag = gflag;
    public boolean getGflag() {
        return gflag;
    public void setScore(int score) {
        this.score = score;
    public int getScore() {
        return score;
    public void setUserName(String userName) {
        this.userName = userName;
    public String getUserName() {
        return userName;
    public void setImage(SocketImage img) {
        this.img = img;
    public SocketImage getImage() {
        return img;
    public void setTimeStamp(Calendar c) {
        this.timeStamp = c;
    public Calendar getTimeStamp() {
        return this.timeStamp;
    public boolean equals(Object obj) {
        try {
            if (obj instanceof User) {
                User comp = (User)obj;
                return comp.getUserName().equals(userName);
            } else {
                return false;
        } catch (NullPointerException npe) {
            return false;
    public void finalize() {
        if (userName != null && !userName.startsWith("OUTOFDATE"))
            System.out.println("User " + userName + " destroyed. " + counter);
    }As you can see...
Every time a User object is created, a static counter variable is incremented and then when an object is destroyed it appends the current value of that static member to the Tomcat log file (via System.out.println being executed on server side).
Below is the log file from an example run in my webapp.
Dustin
User Queue Empty, Adding User: com.db.multi.User@1a5af9f
User Dustin destroyed. 0
User Dustin destroyed. 0
User Dustin destroyed. 0
User Dustin destroyed. 0
User Dustin destroyed. 0
USER QUEUE: false
INSIDE METHOD: false
AFTER METHOD: false
User Dustin destroyed. 1
User Dustin destroyed. 1
User Dustin destroyed. 1
User Dustin destroyed. 1
USER QUEUE: false
INSIDE METHOD: false
AFTER METHOD: false
User Dustin destroyed. 2
User Dustin destroyed. 2
User Dustin destroyed. 2
User Dustin destroyed. 2
User Dustin destroyed. 2
User Dustin destroyed. 2
User Dustin destroyed. 2
User Dustin destroyed. 2
USER QUEUE: false
INSIDE METHOD: false
AFTER METHOD: false
User Dustin destroyed. 3
User Dustin destroyed. 3
User Dustin destroyed. 3
User Dustin destroyed. 3
User Dustin destroyed. 3
User Dustin destroyed. 3
User Dustin destroyed. 3
User Dustin destroyed. 3
User Dustin destroyed. 3
USER QUEUE: false
INSIDE METHOD: false
AFTER METHOD: false
User Dustin destroyed. 4
User Dustin destroyed. 4
User Dustin destroyed. 4
User Dustin destroyed. 4
User Dustin destroyed. 4
User Dustin destroyed. 4
User Dustin destroyed. 4
User Dustin destroyed. 4
User Dustin destroyed. 4
USER QUEUE: false
INSIDE METHOD: false
AFTER METHOD: false
User Dustin destroyed. 5
User Dustin destroyed. 5
User Dustin destroyed. 5
User Dustin destroyed. 5
User Dustin destroyed. 5
User Dustin destroyed. 5
User Dustin destroyed. 5
User Dustin destroyed. 5
User Dustin destroyed. 5
USER QUEUE: false
INSIDE METHOD: false
AFTER METHOD: false
User Dustin destroyed. 6
User Dustin destroyed. 6
User Dustin destroyed. 6
User Dustin destroyed. 6
User Dustin destroyed. 6
User Dustin destroyed. 6
User Dustin destroyed. 6
User Dustin destroyed. 6
User Dustin destroyed. 6
User Dustin destroyed. 6
Joe
USER QUEUE: false
INSIDE METHOD: false
AFTER METHOD: false
User Dustin pulled from Queue, Game created: Joe
User Already Placed: Dustin with Joe
User Dustin destroyed. 7
User Dustin destroyed. 7
User Dustin destroyed. 7
User Dustin destroyed. 7
User Dustin destroyed. 7
User Dustin destroyed. 7
User Dustin destroyed. 7
User Dustin destroyed. 7
User Dustin destroyed. 7
User Dustin destroyed. 7
INSIDE METHOD: false
INSIDE METHOD: false
USER QUEUE: true
INSIDE METHOD: false
INSIDE METHOD: false
User Dustin destroyed. 9
User Joe destroyed. 9
User Dustin destroyed. 9
User Dustin destroyed. 9
User Dustin destroyed. 9
User Dustin destroyed. 9
INSIDE METHOD: true
INSIDE METHOD: false
USER QUEUE: true
INSIDE METHOD: false
INSIDE METHOD: false
INSIDE METHOD: true
INSIDE METHOD: false
USER QUEUE: true
INSIDE METHOD: false
INSIDE METHOD: false
It really does seem to me like finalize is being called multiple times for the same object.
That number should incremement for every instantiated User, and finalize can only be called once for each User object.
I thought this was impossible?
Any help is appreciated!

Thanks...
I am already thinking of ideas to limit the number of threads.
Unfortunately there are two threads of execution in the servlet handler, one handles requests and the other parses the collection of User objects to check for out of date timestamps, and then eliminates them if they are out of date.
The collection parsing thread is currently a javax.swing.Timer thread (Bad design I know...) so I believe that I can routinely check for timestamps in another way and fix that problem.
Just found out too that Tomcat was throwing me a ConcurrentModificationException as well, which may help explain the slew of mysterious behavior from my servlet!
The Timer thread has to go. I got to think of a better way to routinely weed out User objects from the collection.
Or perhaps, maybe I can attempt to make it thread safe???
Eg. make my User collection volatile?
Any opinions on the best approach are well appreciated.

Error : Implementation missing for method 'Constructor'

Hi all,
I have a class(Class Z_CL_A) with attribute 'G_myattribute' and with
1. constructor importing 'L_myattribute'.
2. method 'my_method' exporting table 'EXP_mytable' type 'mytable_type'
There are no syntax errors in 1 & 2.But when I try to activate the class,it says 'implementation missing for method "Constructor".
Here is my class:
class Z_CL_A definition
public
create public .
" public components of class Z_CL_A
" do not include other source files here!!!
public section.
data G_myattribute type myattribute_type .
methods CONSTRUCTOR
    importing
      L_myattribute type myattribute_type .
methods MY_METHOD
    exporting
      !EXP_mytable type mytable_type .
Please let me know what is missing in the class
Thanks
Kukku

You have defined a class with variables and methods but what about implementation. Every class should have a definition and an implementation part.
class Z_CL_A implementation
methods CONSTRUCTOR
importing L_myattribute type myattribute_type .
*Put your code here.*
end method.
methods MY_METHOD
exporting !EXP_mytable type mytable_type .
*Put your code here.*
End method.
Edited by: Naren K Someneni on Jul 16, 2008 3:52 PM

Can I define a constructor for a Custom Component?

I have a custom component which I instantiate through ActionScript. For the sake of clean code, I would like to be able to assign the variables through the constructor like any other class:
var myComp:CustomComponent = new CustomComponent(arg1, arg2, ...);
However, when I try to write a constructor in the Script block for the component, it gives me a compile error telling me that I have multiple constructors:
//In Script tag//
public function CustomeComponent(arg1, arg2 ...):void { ... }
Are we not able to define constructors for Custom Components?

If this post helps, please mark it as such.
If you create an array variable in your MXML component, and then set it with myVar="[val1, val2, val3]" in the opening tag of your component, then you basically have a constructor in MXML.
You can use the [Bindable] metadata tag in three places:
Before a public class definition.
The [Bindable] metadata tag makes usable as the source of a binding expression all public properties that you defined as variables, and all public properties that are defined by using both a setter and a getter method. In this case, [Bindable] takes no parameters, as the following example shows:
[Bindable]
public class TextAreaFontControl extends TextArea {}
The Flex compiler automatically generates an event named propertyChange, of type PropertyChangeEvent, for all public properties so that the properties can be used as the source of a data binding expression.
If the property value remains the same on a write, Flex does not dispatch the event or update the property, where not the same translates to the following test:
(oldValue !== value)
That means if a property contains a reference to an object, and that reference is modified to reference a different but equivalent object, the binding is triggered. If the property is not modified, but the object that it points to changes internally, the binding is not triggered.
Note: When you use the [Bindable] metadata tag before a public class definition, it only applies to public properties; it does not apply to private or protected properties, or to properties defined in any other namespace. You must insert the [Bindable] metadata tag before a nonpublic property to make it usable as the source for a data binding expression.
Before a public, protected, or private property defined as a variable to make that specific property support binding.
The tag can have the following forms:
[Bindable]
public var foo:String;
The Flex compiler automatically generates an event named propertyChange, of type PropertyChangeEvent, for the property. If the property value remains the same on a write, Flex does not dispatch the event or update the property.
You can also specify the event name, as the following example shows:
[Bindable(event="fooChanged")]
public var foo:String;
In this case, you are responsible for generating and dispatching the event, typically as part of some other method of your class. You can specify a [Bindable] tag that includes the event specification if you want to name the event, even when you already specified the [Bindable] tag at the class level.
Before a public, protected, or private property defined by a getter or setter method.
You must define both a setter and a getter method to use the [Bindable] tag with the property. If you define just a setter method, you create a write-only property that you cannot use as the source of a data-binding expression. If you define just a getter method, you create a read-only property that you can use as the source of a data-binding expression without inserting the [Bindable] metadata tag. This is similar to the way that you can use a variable, defined by using the const keyword, as the source for a data binding expression.
The tag can have the following forms:
As far as binding, you can add the [Bindable] tag before the class declaration to make bindable all public properties defined as variables, and all public properties defined by using both a setter and a getter method.

I am using my Apple ID on multiple devices for other people. How can I make icloud work only for my devices?

I am using my Apple ID on multiple devices for other people in my family and now I am getting a new iphone and want to take only the information on my old iphone to the new one without the information on the other devices using the same account. Is there a way to do that?
Also, for the future can I use multiple addresses and apple IDs for the same credit card information?
Thanks in advance,
Marian

Ok, so you want to remove data (contacts, bookmarks, calendar etc) from other users from your iCloud/Apple ID?
If you want to use your ID for your family because it is the account everybody uses to buy stuff then you only need to ensure that your apple ID is set up in the store (settings-store) and then the users of each device and put their own apple ID in icloud/message/facetime/etc.
To set up your device, in my opinion, it is best to back up to itunes, and then plug your new device into itunes and "set up as ..." and select the backup from your device. This will import all your data/settings and your new device will be set up just like your old one.
I am not certain about using the same payment method for more than one account.

How can I use multiple constructor

Hi,
I have some problem to using multiple constructor in java. It shows some error while compiling the following program. can any one give better solution for me.......
public class Test6{
public Test6(){
this(4); /*
C:\Test6.java:5: cannot find symbol
symbol : constructor Test6(int)
location: class Test6
this(4);
Test6(byte var){
System.out.println(var);
public static void main(String[] args){
Test6 t6 = new Test6();
}

A number like 4 is an integer literal. So, you are passing an int to a function that is defined to accept a byte, hence you have a type mismatch. You need to cast the integer literal to a byte before passing it to the function:
this( (byte) 4);

ME01 LSMW multiple record for same material issue.

Hi Experts,
I have an issue with multiple record for the same material and plant when I upload the data from the file. Lets I have the records.
Material        Plant              Start date      Enddate        Vendor          Porg.
1     0010     20060101     99991231     2     0010
1     0010     20060101     99991231     3     0010
When I upload the above data there are 2 IDOCs created when I am using the method LSMW-IDOC method, but only last record is getting updated and the first one is not getting updated in ME01 souce list. But I am getting the success message for both IDOC in LSMW. So I am not sure how to fix this why only last record is updated and not other records??

why do you have 2 idocs?
wouldn't be 1 idoc with 2 items be more logical?
1 record in structure E1EORDH
and 2 records in structure E1EORDM
I believe your 2 IDOCs get posted, but I think your 2nd Idoc overwrites the values entered from the first IDOC.

Multiple initializers for property dataProvider

All I'm trying to do is display xml data from a Rails application in a list., but it doesn't like this:
                    dataProvider="{student_requests.student_request}"
It tells me "multiple initializers for property dataProvider".
Any idea of how to address this? Thanks.
<fx:Script>
        <![CDATA[
            import mx.controls.Alert;
            import mx.rpc.events.FaultEvent;
            import mx.rpc.events.ResultEvent;
            [Bindable]
            private var student_requests:XML;
            private const CONTEXT_URL:String = "http://localhost:3000";
            private function initApp():void {
                student_requestsIndex.send();
            protected function textInput_enterHandler():void
                currentState='List';
            protected function list_changeHandler():void
                currentState='Detail';
            protected function button_clickHandler():void
                currentState='List';
            protected function button_clickHandler_1():void
                currentState='Search';
        ]]>
    </fx:Script>
    <s:states>
        <s:State name="Detail"/>
        <s:State name="List"/>
        <s:State name="Search"/>
    </s:states>
    <fx:Declarations>
        <s:HTTPService
            id="student_requestsIndex"
            url="{CONTEXT_URL}/student_requests.xml"
            resultFormat="e4x"
            result="student_requests=event.result as XML"/>
        <s:HTTPService
            id="student_requestsCreate" url="{CONTEXT_URL}/student_requests.xml"
            method = "POST"
            resultFormat="e4x"
            contentType="application/xml"
            result="student_requestsIndex.send()"/>
        <s:HTTPService
            id="student_requestsUpdate" url="{CONTEXT_URL}/student_requests/{student_requestsGrid.selectedItem.id}/confirm_reques t"
            method="POST"
            resultFormat = "e4x"
            contentType="application/xml"
            headers="{{X_HTTP_METHOD_OVERRIDE: 'PUT'}}" />
    </fx:Declarations>
        <fx:DesignLayer d:id="49" ai:objID="644a1270" d:userLabel="LeftPanel" visible.Search="false" id="designlayer2">
        <s:List skinClass="components.DataList3" x="65" y="96"
                    change="list_changeHandler()"
                    id="list1"
                    dataProvider="{student_requests.student_request}"
                    labelField="student_request">
                <s:ArrayCollection>
                    <fx:String></fx:String>
                    <fx:String></fx:String>
                    <fx:String></fx:String>
                    <fx:String></fx:String>
                    <fx:String></fx:String>
                </s:ArrayCollection>
            </s:List>
        </fx:DesignLayer>

Yeah I removed it but still no data.
I was referencing this:
http://www.adobe.com/devnet/flashcatalyst/articles/building_datacentric_app_flas hcast_flashbuilder_03.html
But he uses Coldfusion, and I tried using the HTTP to connect to data, but the data would never display properly. So I was forced to use HTTPService declarations, which prompted me to change code around. And this was one of it. His approach generated this:
            <s:List skinClass="components.DataList3" x="65" y="96" change="list_changeHandler()" id="list1" creationComplete="list1_creationCompleteHandler(event)" dataProvider="{TypeUtility.convertToCollection(indexResult.lastResult)}" labelField="student_request">
            </s:List>

Multiple MouseEvents for single click

Hello,
I have created a reusable component based on a JPanel.
Our company uses my component in several Swing applications, all of which use a JFrame.
My component has a mouse listener for mousePressed events.
Recently a new app, also based on a JFrame, has started to use my component. In this new Swing app, my component's mousePressed listener gets called THREE TIMES for each mouse pressed.
In all other apps, if the user presses the mouse once, I get only ONE call to my mousePressed listener.
Looking at the stack traces into my mousePressed() method I notice this:
In the apps where mousePressed() is only called once, the stack looks like this:
     at java.awt.Component.processMouseEvent(Component.java:5131)
     at java.awt.Component.processEvent(Component.java:4931)
     at java.awt.Container.processEvent(Container.java:1566)
     at java.awt.Component.dispatchEventImpl(Component.java:3639)
     at java.awt.Container.dispatchEventImpl(Container.java:1623)
     at java.awt.Component.dispatchEvent(Component.java:3480)
     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3450)
     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3162)
     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3095)
     at java.awt.Container.dispatchEventImpl(Container.java:1609)
where as when mousePressed() gets called multiple times, the stack trace shows this:
     at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:218)
     at java.awt.Component.processMouseEvent(Component.java:5131)
     at java.awt.Component.processEvent(Component.java:4931)
     at java.awt.Container.processEvent(Container.java:1566)
     at java.awt.Component.dispatchEventImpl(Component.java:3639)
     at java.awt.Container.dispatchEventImpl(Container.java:1623)
     at java.awt.Component.dispatchEvent(Component.java:3480)
     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3450)
     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3162)
     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3095)
     at java.awt.Container.dispatchEventImpl(Container.java:1609)
Does anybody have any idea of why AWTEventMulticaster would be on the stack for one app and not for another?
And how can I prevent getting called multiple times for a single mouse click?
Thank you,
Ted Hill

You don't understand. My JPanel implements the MouseListener interface and its mousePressed(MouseEvent ) method gets called THREE TIMES on a single mouse click. Normally it should only be called ONCE.
It seems that the app that is using the JPanel extension has somehow registered it as interested in mouse events MULTIPLE TIMES.
I've never seen this before in Swing and was wondering if anyone else has.
Thanks,
Ted

Triggering multiple mails for external Mail id when PO is created

Hi,
I configured PO workflow and i used a standard program to send the mail to the external Mail id's of the users.
The thing is when a PO is created the user whos has to release the PO is getting a Mail in Business Workplace through work flow and simoultaneously a mail will go to his external mail with a message that So and so PO is created please release it.
As he cant keep on monitor his SAP Business workplace,whenever he get a mail to his external id,he will login to SAP and approves or rejects the PO.
Here the probelm is the external mail is keep on triggering for every 15 min as we scheduled the Job for ever 15 min.
So for the same PO number it is giving multiple mails to the external id until it is released.
It should be like one mail should trigger for one PO number instead of multiple mails for the sam PO number.
I'am unable to find the solution.
Please guide me with a solution.
With Regards,
Praveen

Hi Praveen,
1> Goto transaction SWO1.
2> Enter Object/Interface Name as BUS2012 and click on Create Subtype.
3> Enter the required values (you can give ZBUS2012 everywhere....only give Application as R). Place cursor on methods and click on create. Enter details and finally give name of your function module (which you would be creating with the logic of sending mails to selected users) in ABAP tab.
4> Place cursor on method name and click on parameters and create the required parameters. These parameters would receive value from task container.
5> Finally goto transaction SWO6 and delegate this BO to parent BO (which is BUS2012). This would enable the methods of child BO to be available to the parent one.
Try the steps and let me know wherever you get stuck.
Best regards,
Abir

Multiple static synchronized methods locking the same object ?

If I have multiple static synchronized methods in a class will all the methods lock on the same (Class) object ? I guess the answer to this would be yes. In that case is it possible achieve synchronization without an object ie code level synchronization ? If yes, how ?

If I have multiple static synchronized methods in a
class will all the methods lock on the same (Class)
object ? I guess the answer to this would be yes. In
that case is it possible achieve synchronization
without an object ie code level synchronization ? If
yes, how ?There is nothing special about static synchronized methods vs. any other synchronization. It's just shorthand for syncing on the Class object for that class. The effects of synchronization are identical no matter what you sync on.
There's no way to achieve synchronization without an object. Synchronizing always obtains an object's lock. In the case of static synced methods, the object whose lock we obtain is the Class object for that class. As far as syncing goes, it's just another object.
There is no such thing as "code level synchronization" vs. any other kind. All syncing occurs in your Java code over blocks of code. For synced methods, those blocks are the entire respective method bodies.
Having said all that, I have no idea what you're really after or what you're trying to achieve.

Multiple Alerts for Single error in interface is a design not issue with XI

Hi,
This is constraint of alert mechanism in XI.
You get multiple alerts for single error,the reason is that since XI will try multiple times to process a failed message so each time it fails in its tries it will send an e-mail.to stop this the "Suppress multiple alert" box is checked but what it does is that it stops all the alerts of that specific rule until the first one is confirmed.Personally i myself (and other experts too) suggest to leave the box unchecked coz its better to get tons of mails for a specific error rather than not getting any e-mail and thereby wasting time in tracking/solving the issue resulting in revenue loss to client.
As per above comments is it possible to write an ABAP code so that we can stop multiple alerts to be sending to inbox. I am sure if we can delete message from some table then we can stop sending multiple messages to alert inbox and to the subsequent mail id also. I am not sure how alert being generated. I know where they get logged in this table sxmsalertlogger. If someone know how it works in background please let me know the table names.
Regards
Ria

Hi Gaurav,
You can personalize the way in which you receive alerts.
Simply choose Personalization to make individual settings for your alert inbox. You can determine a substitute who will then receive the alerts. In addition, you can choose whether alerts are sent to you time-independently or time-dependently. The default setting is that alerts are sent time-independently to your alert inbox and via e-mail when they occur. You can additionally select the communication methods FAX and SMS for time-independent alert notification.
If you want to receive alerts only on certain days for a certain time, simply select the option for time-dependent sending of alerts and choose Create to create a new table entry. You can then choose the corresponding factory calendar, the time interval, and communication channel. Alerts that arise during this time frame will be sent in any case to your alert inbox. If you have also selected other communication channels, the alerts are additionally sent to you using these other channels.
This above text is from SAP help, do you think by changing anything in personnalisation i can stop multiple alerts. I have some issue with Personalisation link so was wondering would be worth to get tht personalisation issue resolved.
Regards
Ria

GetTreeLock during constructor for swing components

I've noticed some dead locks in our application that are showing up in the call to getTreeLock that exists in the constructor for various JComponents. Specifically, the updateUI method winds up calling validateTree.
I thought it was OK to construct JComponents from any thread, this suggests it is not.
Has anyone else experienced this?

It goes like this:
On win32, thread 0 is our windows message pump. If dispatching one of our messages results in a call from C into Java that constructs a JComponent, we call getTreeLock from thread 0.
Imagine that at the same time, the awt event disptatch thread is trying to show a frame. Since the awt event dispatch thread is part of our process, when the native implemention of the frame calls SendMessage to show the frame, the call to SendMessage blocks until thread 0 calls GetMessage.
Since thread 0 is now blocking waiting for synchronized(getTreeLock()) to return and the awt event dispatch thread has the tree lock - fetched while executing the show() method - we are in a dead lock.
This is not a problem with AWT components, only swing components.
The stack looks like this:
     at java.awt.Component.getTreeLock(Component.java:811)
     at java.awt.Container.invalidateTree(Container.java:1116)
     at java.awt.Container.setFont(Container.java:1148)
     at javax.swing.JComponent.setFont(JComponent.java:2310)
     at javax.swing.LookAndFeel.installColorsAndFont(LookAndFeel.java:89)
     at javax.swing.plaf.basic.BasicButtonUI.installDefaults(BasicButtonUI.java:124)
     at com.sun.java.swing.plaf.windows.WindowsButtonUI.installDefaults(WindowsButtonUI.java:63)
     at javax.swing.plaf.basic.BasicButtonUI.installUI(BasicButtonUI.java:60)
     at javax.swing.JComponent.setUI(JComponent.java:449)
     at javax.swing.AbstractButton.setUI(AbstractButton.java:1616)
     at javax.swing.JButton.updateUI(JButton.java:119)
     at javax.swing.AbstractButton.init(AbstractButton.java:1952)
     at javax.swing.JButton.<init>(JButton.java:109)
     at javax.swing.JButton.<init>(JButton.java:64)
It seems like we could simply have the invalidateTree method return early if there is no parent or there are no children or somesuch.
A work around we've done is to have the updateUI method delegate to the event dispatch thread. This is a drag as we need to subclass all the JComponents and make sure developers use the safe subclass.

How to create a constructor for this class?

Hi everybody!
I have an applet which loads images from a database.
i want to draw the images in a textarea, so i wrote an inner class, which extends textarea and overrides the paint method.
but everytime i try to disply the applet in the browser this happens:
java.lang.NoClassDefFoundError: WohnungSuchenApplet$Malfl�che
     at java.lang.Class.getDeclaredConstructors0(Native Method)
     at java.lang.Class.privateGetDeclaredConstructors(Class.java:1590)
     at java.lang.Class.getConstructor0(Class.java:1762)
     at java.lang.Class.newInstance0(Class.java:276)
     at java.lang.Class.newInstance(Class.java:259)
     at sun.applet.AppletPanel.createApplet(AppletPanel.java:567)
     at sun.plugin.AppletViewer.createApplet(AppletViewer.java:1778)
     at sun.applet.AppletPanel.runLoader(AppletPanel.java:496)
     at sun.applet.AppletPanel.run(AppletPanel.java:293)
     at java.lang.Thread.run(Thread.java:536)
so my class has no own constructor, it just has the paint method overwritten.
my class looks like this:
public class Malfl�che extends javax.swing.JTextArea{
public void paint(Graphics g){
Color grey=new Color(220,220,220);
g.drawImage(img,10,10,null);
how should a constructor for this class look like?
sorry i am quite new to this, so i really dont have a clue!
my class does not have any attributes or requires any so it doesnt need a constructor, doesnt it?
thanks a lot
tim

If you have no constructor you cant instanciate (I know i just murdered that spelling) the object.
Malfl�che thisHereThingie = new Malfl�che()assuming that you want to run that class by itself you will need a main method that has the preceeding code in it. If you are running it from another class you need to instanciate it... but anyway at the very least for a constructor you need.
public Malfl�che(){

Multiple constructors for methods

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