Accessing thirdy party class variable...

I am pretty new to JAVA, and I was wondering if the following is doable.
I have a class A and when it runs it invokes two different classes B and C. Is there anyway I can access a variable in B from C or vice versa? Any help would be greatly appreciated. Thanks!
sincerely,
Yosep

accessing a 3rd party class variable?
C.someClassVariableOr do you mean a instance variable.
Depends on the scoping too by the way.
Anyway way, if you want to access an instance variable, you'll have to have a reference to the object instance it's from.

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How to access the parent class variable or object in java

Hi Gurus,
I encounter an issue when try to refer to parent class variable or object instance in java.
The issue is when the child class reside in different location from the parent class as shown below.
- ClassA and ClassB are reside in xxx.oracle.apps.inv.mo.server;
- Derived is reside in xxx.oracle.apps.inv.mo.server.test;
Let say ClassA and ClassB are the base / seeded class and can not be modified. How can i refer to the variable or object instance of ClassA and ClassB inside Derived class.
package xxx.oracle.apps.inv.mo.server;
public class ClassA {
    public int i=10;
package xxx.oracle.apps.inv.mo.server;
public class ClassB extends ClassA{
    int i=20;
package xxx.oracle.apps.inv.mo.server.test;
import xxx.oracle.apps.inv.mo.server.ClassA;
import xxx.oracle.apps.inv.mo.server.ClassB;
public class Derived extends ClassB {
    int i=30;
    public Derived() {
       System.out.println(this.i);                  // this will print 30
       System.out.println(((ClassB)this).i); // error, but this will print 20 if Derived class located in the same location as ClassB
       System.out.println(((ClassA)this).i); // error, but this will print 20 if Derived class located in the same location as ClassA
    public static void main(String[] args) {
        Derived d = new Derived();
Many thanks in advance,
Fendy

Hi ,
You cannot access the controller attribute instead create an instance of the controller class and access the attribute in the set method
OR create a static method X in the controller class and store the value in that method. and you can access the attribute by
Call method class=>X
OR if the attribute is static you can access by classname=>attribute.
Regards,
Gangadhar.S
Edited by: gangadhar rao on Mar 10, 2011 6:56 AM

Private or Protected access for super class variables

What is the best practice...
Assume there is a class hierachy like
Person (Super class) / StaffMember/ Professor (Sub class)
1) The best way is to keep all the instance variables of each and every class private and access the private variables of super classes through subclass constructors (calling "super()")
Ex:-
public class Person {
private String empNo;
public Person (String empNo) {
this.empNo = empNo;
public class Professor extends Person {
private String ........;
private int ...........;
public Professor (String pEmpNo) {
super(pEmpNo);
OR
2)Changing the access level of the super class variables into "protected" or "default" and access them directly within the sub classes...
Ex:-
public class Person {
protected String empNo;
public Person () {
public class Professor extends Person {
String ........;
int ...........;
public Professor (String empNo) {
this.empNo = empNo;
Thank you...

i'd think that you'd be better off relaying your initial values through the super class's constructor that way you'll get cleaner code, there's a possibly of inconsistency with option 2. i.e. you can then write code in your super classes to generally handle and properly initialize the instance variables while in the case of option 2, you'll have arbitrary constructors performing arbitrary initialization procedures

Accessing a Sub class variable in a Super Class

Hi ,
Is there any easiest way to access a Subclass Variable in a Super Class.
Class Super1{
Class sub extends Super1
private String substring1;
In my application the 'substring1' values is not null .But all fields in Super1 class are null .
How can i access the value of the Subclass Variable in Super class .
Thanks

This would be a way to make the superclass dependent on subclass behavior. Of course this only makes sense if getSubString() is likely to have multiple different implementations in different subclasses.
public abstract class Super {
public String getString() {
   return "SuperString" + getSubString();
protected abstract String getSubString();
public class Sub extends Super {
private String substring;
protected String getSubString() {
   return substring;
}Using this just to access a variable whose contents differ from subclass to subclass is overkill. If you want each subclass to provide a different substring, create a constructor with a substring parameter in the superclass instead:public class Super {
private String substring;
protected Super(String substring) {
   this.substring = substring;
public String getString() {
   return "SuperString" + substring;
public class Sub extends Super {
public Sub() {
   super("substring");
}

Accessing SPML Object class variable on SUN IDM Form or workflow

Hi All,
Can anyone suggest me how we can access the SPML variable on SUN IDM Form and workflow?
e.g
I have object class deffination in SPML configuration with schema deffination as below
<Configuration name='SPML'>
<Extension>
<Object> <Attribute name='classes'>
<List>
<Object name='person'>
<Attribute name='type' value='User'/>
<Attribute name='form' value='SPMLPerson'/>
<Attribute name='default' value='true'/>
<Attribute name='identifier' value='uid'/>
</Object>
</List>
</Attribute>
<Attribute name='schemas'>
<List>
<String>
<![CDATA[
                   <schema xmlns="urn:oasis:names:tc:SPML:1:0"
                  ...SPML standard schema...
                  </schema>
                   ]]>
</String>
<String>
<![CDATA[
                   <schema xmlns="urn:oasis:names:tc:SPML:1:0"
                   ...Waveset custom schema...
                   </schema>
                   ]]>
</String>
</List>
</Attribute>
</Object>
</Extension>
</Configuration>
Where I deffine my custom schema with all attributes that I want to view on SUN IDM custom form.
I am able to set value from ModifyRequest for the variable but not able to get it on the Form or workflow.
I did try with below expression to get the variable but no luck.
<ref>attribute_name</ref>
<ref>SPML.attribute_name</ref>
<ref>SPML.Object_name.attribute_name</ref>
Please suggest how we can access the variable?
Any information will be appricated.
Regards,
vinash

Hi All,
Can anyone suggest me how we can access the SPML variable on SUN IDM Form and workflow?
e.g
I have object class deffination in SPML configuration with schema deffination as below
<Configuration name='SPML'>
<Extension>
<Object> <Attribute name='classes'>
<List>
<Object name='person'>
<Attribute name='type' value='User'/>
<Attribute name='form' value='SPMLPerson'/>
<Attribute name='default' value='true'/>
<Attribute name='identifier' value='uid'/>
</Object>
</List>
</Attribute>
<Attribute name='schemas'>
<List>
<String>
<![CDATA[
                   <schema xmlns="urn:oasis:names:tc:SPML:1:0"
                  ...SPML standard schema...
                  </schema>
                   ]]>
</String>
<String>
<![CDATA[
                   <schema xmlns="urn:oasis:names:tc:SPML:1:0"
                   ...Waveset custom schema...
                   </schema>
                   ]]>
</String>
</List>
</Attribute>
</Object>
</Extension>
</Configuration>
Where I deffine my custom schema with all attributes that I want to view on SUN IDM custom form.
I am able to set value from ModifyRequest for the variable but not able to get it on the Form or workflow.
I did try with below expression to get the variable but no luck.
<ref>attribute_name</ref>
<ref>SPML.attribute_name</ref>
<ref>SPML.Object_name.attribute_name</ref>
Please suggest how we can access the variable?
Any information will be appricated.
Regards,
vinash

Inner class access to outer class variables

class X extends JTextField {
int variable_a;
public X() {
setDocument(
new PlainDocument() {
//here i need access to variable_a
i don't want to make variable_a a static member though, so does anyone know how to do it?

Generally, you can reference your variable_a just as you would any other variable except if your inner class also defines a variable_a. However, to produce a reference to the enclosing outer class object you write "OuterClassName.this". So, to get to your variable I think you would write "X.this.variable_a". I hope this helps.

How to access class variables in anonymous class??.

I have a boolean class level variable. Fom a button action , this boolean will set to true and then it used in anonymous class. In anonymous class, I am getting default value instead of true. Could u anyone help in this plzzz.

first of all, you don't want parent because that is something that Containers use to remember their containment hierarchy. you are thinking of super which is also incorrect, because that has to do with inheritance.
the problem here is a scoping problem. you generally would use final if you were accessing variables in an anonymous class that are in the local scope. in this case, you just need to create some test code and play with it. snip the code below and play with it. it shows both the given examples and some additional ways to change/display class variables.
good luck, hackerx
import javax.swing.*;
import java.awt.event.*;
public class Foo extends JPanel
     private boolean the_b = true;
     public static void main(String[] args)
          Foo f = new Foo();
          JFrame frame = new JFrame();
          frame.getContentPane().add(f);
          frame.pack();
          frame.show();
     public Foo()
          // get your button
          JButton b = new JButton("Not!");
          b.addActionListener(new ActionListener()
               public void actionPerformed(ActionEvent ae)
                    // *** uncomment these to play around ***
                    // Foo.this.the_b = false; // this will work, but unnecessary
                    // the_b = false; // this works fine too
                    notFoo();
          this.add(b);
          // something to show the value that accesses a class variable
          // using an inner class instead of final nonsense
          DisplayThread t = new DisplayThread();
          t.start();
     private void notFoo()
          the_b = !the_b;
     class DisplayThread extends Thread
          public void run()
               while(true)
                    System.err.println("boolean value: " + the_b);
                    try {
                    sleep(1000);
                    } catch(InterruptedException ie) {}
}

Local variable can't be accessed from inner class ???????? Why ??????

Plesae help, help, help. I have no idea what to do with this bug.........
<code>
for ( int i = 0; i <= 2; i++ ) {
for ( int j = 0; j <= 2; j++ ) {
grids[i][j] = new MyButton ();
grids[i][j].setBorder(but);
getContentPane().add(grids[i][j]);
MyButton sub = grids[i][j];
sub.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if ( sub.getState() == 0 ) {
     sub = new MyButton( (Icon) new ImageIcon(imageFile));
     if ( imageFile.equals("cross.jpg") ) {
          sub.changeState(1);
     else {
          sub.changeState(2);
</code>
The compiler complains that "sub" is in the inner class, which is the ActionListener class, must be declared final. Please tell me what to do with it. I want to add an ActionListener to each MyButton Object in the array. Thanks ......

OK, now I changed my code to this :
for ( int i = 0; i <= 2; i++ ) {
for ( int j = 0; j <= 2; j++ ) {
    grids[i][j] = new MyButton ();
    grids[i][j].setBorder(but);
    getContentPane().add(grids[i][j]);
    grids[i][j].addActionListener(new ActionListener() {
     public void actionPerformed(ActionEvent e) {
        if ( grids[i][j].getState() == 0 ) {
           grids[i][j] = new MyButton( (Icon) new ImageIcon(imageFile));
          if ( imageFile.equals("cross.jpg") ) {
           grids[i][j].changeState(1);
          else {
          grids[i][j].changeState(2);
[/cpde]
Thanks for your advice !!!!!!
Now the compiler says that i and j are local variables accessed from inner classes, needs to be declared final. How can I solve this then ???

How do i access a third party .class file

Hi,
I am new to both java and enterprise 8, and would greatly appreciate some help.
I have a third party .class file and want to include it in a project so i can call it's methods etc. I can access it by creating an object as follows
thirdPartyClass tpc= new thirdPartyClass();and then create a .class file of my own using javac at the command line without any probles, but if I use the same code in enterprise 8 it reports an error stating "cannot access MyProjectName.thirdPartyClass" could someone please tell me how to reference this file as so far I have not been able to find anything.
Thanks for any help.

Thanks for the suggestions it appears I was doing more or less the right things but miss reading the error message:
Cannot access keyword.classes.thirdPartyClass
bad class file C:\java\keyword\classes\thirdPartyClass
class file contains wrong class: thirdPartyClass
please remove or make sure it appears in the correct subdirectroy of the classpath.
While looking I have found that the classes do not contian src folders of Javadoc so I will go see if the third party can supply a Jar file or similar.
Thanks

I want to access that BEA instance variable inside of a external java class

Hi,
This is N.pradeep. I am a java programmer, and I am new to BEA AquaLogic BPM studio5.7. I have a question regarding how to retrieve an instance variable of BEA Aqua Logic to an external Java Program. i.e. I want to access that BEA instance variable inside of a external java class, and vice versa.

You can use PAPI or PAPI-WS for accessing BPM instance variable from a Java code, thougt I am not sure how the reverse will be done. Assuming that you are aware aof PAPI-WS and have created the necessary stubs out of the PAPI-WS WSDL using Axis, you can access instance variables using the API's or operations defined therein.
Thanks and Regards
Vivek Nandey
BEA Certified Developer for Integration Solutions
[email protected]

Thread cannot access the class variables.

Hi
I have below code snippet : (Only section of which I have copied below)
public class ProcessAppendAction extends HttpServlet implements Runnable{
     public ProcessAppendAction ()
MI_OS_APPEND port ;
protected void doGet(
          HttpServletRequest request,
          HttpServletResponse response)
          throws ServletException, IOException {
          //TODO : Implement
port =
                    (MI_OS_APPEND) obj.getLogicalPort(
                         "MI_OS_APPENDPort",
                         MI_OS_APPEND.class);
Thread[] threads = new Thread[noOfThreads];
ProcessAppendAction run = new ProcessAppendAction(req);
                                        Thread th = new Thread(run);
                                        threads[no] = th;
                              threads[no].start();
                              threads[no].join();
public ProcessAppendAction(DT_REQUEST_APPEND req) {
          this.requestObj = req;
          // TODO Auto-generated constructor stub
public void run()
          try
               DT_RESPONSE res = this.port.MI_OS_APPEND(requestObj);
                              catch(Exception e)
                                   int ch=0;
                                   ch++;
          }     In above code I am successfully creating an object in line :
port =
                    (MI_OS_APPEND) obj.getLogicalPort(
                         "MI_OS_APPENDPort",
                         MI_OS_APPEND.class);But when I am trying to access this port variable in run method it is giving null.
Port in my code is a class variable.
Is it the case that thread cannot access class variable !!

money321 wrote:
ok, I have removed join() from just after start().So that now the Servlet can return before the new Thread has finished. Is this what you want?
First I did invoked all threads and then in second loop i invoked Join on all threads.I don't understand. Why do you need to join() all the threads since you only start one thread in this request. What am I missing?
>
Now, my problem.
It was solved when I substituted the line
ProcessAppendAction run = new ProcessAppendAction(req)
with
ProcessAppendAction run = new ProcessAppendAction(req,port);Of course. Instance variables in Servlet instances are a no-no so passing the 'port' though an instance variable is just wrong.
>
That is passes port alongwith req while creating thread object.
But still if class variables are not thread safe, then it means if I pass object 1 to thread 1.
And then try to pass object 2 to thread 2, it might be possibility that object 1 of thread 1 might be replaced by object 2.
So, thread 1 will get an updated value object 2.Yep - that is why you should not use instance variables in Servlets and why they are not thread safe.
>
Which is not what I intend to do...:-)

Outer Class Accessing Inner Classes Variables

Hi Everyone,
Should an outer class directly access the private member variables of its inner class? Or should it get their values by calling an appropriate 'getXXX()' method?
Just wondering.
Thx.

If the outer class trys to access the variable that is declared in the inner class with in a class and outside the method, then it can access in the following example
class outer
     private int x=10;
     class inner
          int y=20;
     public void getOutput()
          inner in=new inner();
          System.out.println("The value of y is" +in.y);
     public static void main(String args[])
          outer out=new outer();
          out.getOutput();
};

How to access an element using its name or id if it is not a class variable?

I am trying to retrieve the element I added to my UI in a different function. I am using actionscript 3. I know I can put the variable into a class variable, so it can be access anywhere in the class, but I have too many elements. Is there anyway I could access them without putting them into class variable?
Thanks.
public class Test extends SkinnableContainer{
// private var image:Image; <-- I try not to do this, too messy
private function func1() {
    var image:Image = new Image();
    addElement(image);
private function func2() {
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Here is what works for me:
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
               xmlns:s="library://ns.adobe.com/flex/spark"
               xmlns:mx="library://ns.adobe.com/flex/mx"
               creationComplete="init()"
               minWidth="955" minHeight="600">
    <fx:Declarations>
        
    </fx:Declarations>
    <fx:Script>
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            private function init():void
                image = new Image();
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                trace(this["image"]);
        ]]>
    </fx:Script>
</s:Application>

Access to class variables

Hi everybody
I wrote a class with following constructor method :
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                               ClassNotFoundException,
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        trans.connect();
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        trans.disconnect();
"how can i use from "rep" variable in my jsp page??

In this example rep is a method variable, not a class variable. So you cannot access it outside the constructor. Make it a class variable and generate an accessor method for it.
Ronald

Class variable declaration

Hello.
Just looking through some code and I see a class variable declared as so...
static final MessageDigest digestFunction;
static { // The digest method is reused between instances to provide higher entropy.
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Thanks for any help, just a little confused!

Sir_Dori wrote:
Ah yes, of course it could not be within the constructor as it is static, sorry.
So when would the class be loaded? Could this be the first time the ClassName.staticBlockVar is accessed, Most likely, yes. The first time something else uses the class. Classloading in Java is lazy.
Also, is the code not reevaluated every time it is referenced ?No. Only when the class is loaded (actually, when it's initialized, but usually it boils down to the same thing)
You can write some simple tests for this, by writing a constructor and a static initializer, then instantiating it twice, for example. Don't be afraid to just play around with code to test assumptions. I find JUnit very handy for experimenting with assumptions.

Accessing thirdy party class variable...

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