Help , inner class included.

hello all :
I want to check a java file , which include inner class or not , and I want to get the inner class name of it , how can I do it ?
looks like this :
java InnerClassChecker Mother.java
InnerClassA
InnerClassB
InnerClassC
thank u.

I would suggest compiling Mother.java and then you can do this with the Class object of the mother class.
Class c = motherObj.getClass();Then you can call c.getClasses(). This will return all public inner Classes of Mother.
If you dont have the mother Object and want to do it with the parameter it would look like this:
java InnerClassChecker Mother.class
Then your InnerClassChecker takes the <param> in its main method and calls
Class.forName(<param>) to load the Mother class object.

Similar Messages

Inner Class included in build.xml

I am trying to get my build.xml to include an inner class that gets created when my web service class is compiled. How do I make this file a part of the final ear file in the build.xml file?? I can add it by hand afterwards but that seems too complicated. Thanks.

Sorry about leaving out the build file. Here is the whole file:
<project name="TestProgram" default="all" basedir=".">
<property name="source" value="."/>
<property name="build" value="${source}/build"/>
<property name="war_file" value="TestProgram.war" />
<property name="ear_file" value="TestProgram.ear" />
<property name="namespace" value="http://www.test.com"/>
<target name="all" depends="clean, compile, ear"/>
<target name="clean">
<delete dir="${build}"/>
</target>
<target name="compile">
<mkdir dir="${build}"/>
<javac srcdir="${source}" destdir="${build}" includes="TestProgram.java"/>
</target>
<target name="ear">
<servicegen
destEar="${build}/${ear_file}"
warName="${war_file}">
<service
javaClassComponents="TestProgram.agents.TestProgram"
targetNamespace="${namespace}"
serviceName="TestProgram"
serviceURI="/TestProgram"
generateTypes="True"
expandMethods="True">
</service>
<classpath>
<pathelement path="${build}"/>
<pathelement path="${java.class.path}"/>
</classpath>
</servicegen>
</target>
</project>
The TestProgram class has an inner class that is a Comparator. The TestProgram needs the inner class but the client program that is calling TestProgram doesn't. Thanks for the help.

HELP: Inner Class vs. Private Member

I use "javadoc -private" to create documents with inner classes. As a result, all private fields and methods, which I don't need, show up in the same document. Is there any way I can have inner classes without private members?

how do you declare your inner class?
Is it (public)
public static class MyInnerClassor (private)
private static class MyInnerClassor (package)
static class MyInnerClassor (protected)
protected static class MyInnerClassTry to change the way you declare the inner class. Use protected or package or public instead.

Help: Factory Class using Inner Class and Private Constructor?

The situation is as follows:
I want a GamesCollection class that instantiates Game objects by looking up the information needed from a database. I would like to use Game outside of GamesCollection, but only have it instantiated by GamesCollection to ensure the game actually exist. Each Game object is linked to a database record. If a Game object exist, it must also exist in the database. Game objects can never be removed from the database.
I thought about making the Game object an inner class of GamesCollection, but this means that Game class constructor is still visible outside. So what if I made Game constructor private? Well, now I can't create Game objects without a static method inside Game class (static Object factory).
Basically what I need is a constructor for the inner Game class accessible to GamesCollection, but not to the rest of the world (including packages). Is there a way to do this?

leesiulung wrote:
As a second look, I was initially confused about your first implementation, but it now makes more sense.
Let me make sure I understand this:
- the interface is needed to make the class accessible outside the outer classBetter: it is necessary to have a type that is accessible outside of GameCollection -- what else could be the return type of instance?
- the instance() method is the object factory
- the private modifier for the inner class is to prevent outside classes to instantiate this objectRight.
However, is a private inner class accessible in the outer class? Try it and see.
How does this affect private/public modifiers on inner classes?Take about five minutes and write a few tests. That should answer any questions you may have.
How do instantiate a GameImpl object? This basically goes back to the first question.Filling out the initial solution:
public interface Game {
    String method();
public class GameCollection {
    private static class GameImpl implements Game {
        public String method() {
            return "GameImpl";
    public Game instance() {
        return new GameImpl();
    public static void main(String[] args) {
        GameCollection app = new GameCollection();
        Game game = app.instance();
        System.out.println(game.method());
}Even if you were not interested in controlling game creation, defining interfaces for key concepts like Game is always going to be a good idea. Consider how you will write testing code, for example. How will you mock Game?

How to include the inner classes in a jar file in netbeans ide

Dear java friends
how to say to netbeans ide that it has to include the
inner classes in the jar file.
(i have one single applet class
with two inner classes that show up
in the build/classes file but not in the jar).
The applet works in the viewer but not
in the browser (I believe because the
xxx$yyy etc should be in the jar)
willemjav

First, please stop posting the same question multiple times:
Duplicate of http://forum.java.sun.com/thread.jspa?threadID=5269782&messageID=10127496#10127496
with an answer.
Second, If your problem is that you can't do this in NetBeans, you need to post to somewhere that provides NetBeans support - like the NetBeans website's mailing list. These forums do not support NetBeans (or any other IDE) - they are Java language forums.

HELP: Cannot refer to non-final variable inside inner class

Below is a function that WAS working beautifully. I had to restructure many things in my code base to suit a major change and I have to make this function static. Since I made this function static, I get some errors which are displayed in comments next to the line of code.
Can anyone offer any advice how to fix this?
static private void patchSource( final Target target, final TargetResolver resolver, final TexSheetCommand args ) throws Exception
     boolean bDone = false;
     Element e;
     SAXReader sax          = new SAXReader();
     FileInputStream fis     = new FileInputStream( args.getInputFile() );
     Document document     = sax.read( fis );
     Element root = document.getRootElement();
     if( root.getName().equals( "Sheet" ) )
          XMLParser.iterateElements( root,     new XMLElementCallback()
                                                  public void onElement( Element element )
                                                       XMLParser.iterateAttributes( element,     new XMLAttributeCallback()
                                                                                               public void onAttribute( Element element, Attribute attribute )
                                                                                                    if( attribute.getName().equals( "guid" ) )
                                                                                                         e = element; // PROBLEM: Cannot refer to a non-final variable e inside an inner class defined in a different method
                                                                                                         // WARNING: Type safety: The expression of type Iterator needs unchecked conversion to conform to Iterator<Attribute>
                                                                                                         for( Iterator<Attribute> it = element.attributeIterator(); it.hasNext(); )
                                                                                                              Attribute a = (Attribute)it.next();
                                                                                                              if( a.getName().equals( "randOffset" ) )
                                                                                                                   Integer i = new Integer( resolver.getTotalPermutations() );
                                                                                                                   a.setValue( i.toString() );
                                                                                                                   bDone = true; // PROBLEM: Cannot refer to a non-final variable bDone inside an inner class defined in a different method
          if( ( !bDone ) && ( e != null ) )
               Integer i = new Integer( resolver.getTotalPermutations() );
               e.addAttribute( "randOffset", i.toString() );
     FileOutputStream fileOut     = new FileOutputStream( args.getInputFile() );
     OutputFormat format               = OutputFormat.createPrettyPrint();
        XMLWriter xmlWriter               = new XMLWriter( fileOut, format );
        xmlWriter.write( document );
        fileOut.close();
}PS.) on a side note there is a warning on one of the lines too. Can anyone offer help on that one too?!
Thanks in advance.

It is already set to that - it does look correct in Eclipse, honest.
It's just the block that's gone crazy with the formatting. I've spent around 10 minutes trying to tweak it just so it displays correctly but it wasn't making sense.
I'd rather not turn this conversation into a judgement of my code-style - I already understand that it doesn't conform to the 'Java way' and I've had Java programmers bash me about it for a long time.

Help,about why we use inner class?

Hi,
when i read "java Tutorial"
i found there is one chapter about inner class .
i copy it down as follow.
the context is about there is a class Stack, and this class want to implement some function of interface Iterator,but as the book said
we should not let class Stack implement the Iterator directly, we should add a inner class inside the Stack .
i know it's very import ,but i still can not understand the reason why add a inner class here.
hope somebody can explain it a little more for me or give an example.
thank in advance!
Iterator defines the interface for stepping once through the elements within an ordered set in order. You use it like this:
while (hasNext()) {
next();
The Stack class itself should not implement the Iterator interface, because of certain limitations imposed by the API of the Iterator interface: two separate objects could not enumerate the items in the Stack concurrently, because there's no way of knowing who's calling the next method; the enumeration could not be restarted, because the Iterator interface doesn't have methods to support that; and the enumeration could be invoked only once, because the Iterator interface doesn't have methods for going back to the beginning. Instead, a helper class should do the work for Stack.
The helper class must have access to the Stack's elements and also must be able to access them directly because the Stack's public interface supports only LIFO access. This is where inner classes come in.
Here's a Stack implementation that defines a helper class, called StackIterator, for enumerating the stack's elements:
public class Stack {
private Object[] items;
//code for Stack's methods and constructors
not shown
public Iterator iterator() {
return new StackIterator();
class StackIterator implements Iterator {
int currentItem = items.size() - 1;
public boolean hasNext() {
public Object next() {
public void remove() {
or you can visit here
http://java.sun.com/docs/books/tutorial/java/javaOO/innerclasses.html

the context is about there is a class Stack, and this
class want to implement some function of interface
Iterator,but as the book said
we should not let class Stack implement the Iterator
directly, we should add a inner class inside the
Stack .Simply because the implementation of the Iterator is nobody's business. By declaring it to be a private inner clss, nobody will ever know about it and only see the Iterator interface.

Deployment problem: Inner class not included

Hi, All:
I am trying to deploy my Java application using JDeveloper 3.2. I was be able to successfully deployed it when I first designed the project, even some of the files also have inner classes. Now I have added some new inner classes to a public class and tried to re-deploy it. However how hard I tried (I have tried to rebuild the project, redefine the depoyment profile, even tried to add these class files directly through the advanced tab), the newly added inner class will not be able to be added to the deployed Jar file. I have checked the class files under myclass directory, and found all the inner class files are there, and I can run the application in JDeveloper without any problem. I wonder if there is any tricks to solve this problem. (Other than use the jar command).
Thanks,
Peter

Also, it's probably a good idea to name your packages different than your classesMoreover, common naming conventions dictate you should never even use capitals in your package names if I'm not mistaken. Whereas class names should always at least begin with a capital.
This will help prevent a lot of confusion, both for the developer and the IDE. ;-)

Inner classes help

Hello, I was just wondering if someone can help me understand inner classes a little. If I have the following code:
class Parent
private String myString = new String(�I am parent�);
public void writeIt()
System.out.println(myString);
public void displayIt()
System.out.println((new InnerParent()).readMyString());
class InnerParent
public String readMyString()
return myString;
class Child extends Parent
private String myString = new String(�I am child�);
public void writeIt()
System.out.println(myString);
If we execute the following lines on the code
Child myChild = new Child();
Parent myParent = new Parent();
myChild.writeIt();
myParent.writeIt();
myChild.displayIt();
myParent.displayIt();
Why does the following code display?
I am child
I am child
I am parent
I am parent
==
Thanks!

Child myChild = new Child();
Parent myParent = new myChild();you again made a mistake,
it should be
Child myChild = new Child();
Parent myParent = new Child();
and now the output is
I am child
I am child
I am parent
I am parent
because, myChild.writeIt(); displays the stirng, I am child, straightforward, when it comes to myParent.writeIt(); it displays the string I am child because, myParent is of the type Child() which has been casted back to Parent, since child extends parent this can be done, and so, it just behaves as if it is a child, and so it displays I am child. when it comes to myChild.displayIt(), it uses the string in the Parent class, since it extends Parent and it does not override that method, it has to use that string ,and so it displays I am Parent, and similarly for the myParent.displayIt(), also it displays I am Parent. Hope you Understood now.

Need Help in Inner Classes

Hi
I joined as a faculty last week in an institution. To take class I need some information about inner classes in java.
Basically i need where we use this concept in real time application. Now it is used by the developer or not? Moreover how it is working in java?
Please somebody help me out...
thanks in advance
Chithrakumar

I once wrote the following example class showing a bit of inner classes"public class Star {
     private String name;
     public Star(String name) { this.name= name; }
     public class Planet {
          private String name;
          public Planet(String name) { this.name= name; }
          public class Moon {
               private String name;
               public Moon(String name) { this.name= name; }
               public String toString() { return name+" (orbiting "+Planet.this+")"; }
          public String toString() { return name+" (orbiting "+Star.this+")"; }
     public String toString() { return name; }
     public static void main(String[] args) {
          System.out.println(new Star("sun").new Planet("earth").new Moon("moon"));
}Study it, run it and see if you understand what this is all about.
kind regards,
Jos

Please need help with Inner Classes

Hi! I have the following inner class, but it is not an "explicit" inner class:
import java.util.*;
public class EXTERIOR_NOEXPLICITA {
     private Vector i;
     public void llena_Vector(int a){
          i = new Vector();
          for(int z=0;z<=a;z++)
               i.addElement(""+z);
     public Enumeration test() {
          return new Enumeration(){
               int item = i.size()-1;
               public boolean hasMoreElements(){
                    return(item >= 0);
               public Object nextElement(){
                    if(!hasMoreElements())
                         throw new NoSuchElementException();
                    else
                         return i.elementAt(item--);
My question is, how can I put it in an explicyt inner class?
Plese help me! =)
Raul

I am not entirely sure what you mean by explicit inner class. If you mean converting your anonymous class into a nested class, then it is quite easy:
import java.util.*;
public class EXTERIOR_NOEXPLICITA {
private Vector i;
public void llena_Vector(int a) {
    i = new Vector();
    for (int z = 0; z <= a; z++)
      i.addElement("" + z);
private final class MyEnumeration implements Enumeration {
    int item = i.size() - 1;
    public boolean hasMoreElements() {
      return (item >= 0);
    public Object nextElement() {
      if (!hasMoreElements())
        throw new NoSuchElementException();
      else
        return i.elementAt(item--);
public Enumeration test() {
    return new MyEnumeration();

Question about inner class - help please

hi all
i have a question about the inner class. i need to create some kind of object inside a process class. the reason for the creation of object is because i need to get some values from database and store them in an array:
name, value, indexNum, flag
i need to create an array of objects to hold those values and do some process in the process class. the object is only for the process class that contains it. i am not really certain how to create this inner class. i tried it with the following:
public class process{
class MyObject{}
List l = new ArrayList();
l.add(new MyObject(....));
or should i create the object as static? what is the benifit of creating this way or static way? thanks for you help.

for this case, i do need to create a new instance of
this MyObject each time the process is running with a
new message - xml. but i will be dealing with the case
where i will need a static object to hold some
property values for all the instances. so i suppose i
will be using static inner class for that case.The two situations are not the same. You know the difference between instance variables and static variables, of course (although you make the usual sloppy error and call them static objects). But the meaning of "static" in the definition of an inner class is this: if you don't declare an inner class static, then an instance of that inner class must belong to an instance of its containing class. If you do declare the inner class static, then an instance of the inner class can exist on its own without any corresponding instance of the containing class. Obviously this has nothing to do with the meaning of "static" with respect to variables.

Help! - JRE can't find classes that use inner classes!

Whenever I try to launch an app using the JRE, if the class was built with an inner class definition, the JRE says it can't find the class.
For instance:
I created a class called GUI, which contains anonymous inner class definitions for the button handlers: addActionListener(new ActionListener()){, etc.
When I compile this class I get GUI.class and GUI$1.class
When I try to launch this using the JRE:
jre -cp c:\progra~1\myApps GUI
The JRE spits out
'Class not found: GUI'
BUT if I go back and remove the action handlers so that the only compiled class file is GUI.class (not GUI$1.class) then the JRE can find the class no problem.
What in the good Lord's name is going on here?

Thanks for the response. Got the 1.2.2 version of the JRE, where I guess you no longer invoke jre.exe (no such file exists) but java.exe instead (not well documented).
Also, the newer version of the JRE has no problems locating classes, so I guess I'm OK.

Adapters vs anonymous inner class (please help)

I am trying to clean up my code by using anonymous inner classes to handle some action events. My code looks like this but I get an error
Button.addActionListener(new MyClass() {
public void actionPerformed(ActionEvent e) {
my_Button_actionPerformed(e);
it says that it cant find MyClass, but I thought I dont need to define it becaue I am defining it here, isnt that the point of a anonymous inner class

yourBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
});(BTW: use code tags in posting!)

Private inner classes

I'm trying to complete a "turn the lightbulb on and off" program, but when I try to draw circle2 in the
ButtonListener class I get an error message cannot find symbol. This is in reference to the Graphics
variable "page" created in the paintComponent method below. Shouldn't the inner class, private or
public inherit all data variables including objects from the parent class, in this case, the Bulb class? The code is below.
By the way, this IS NOT a school assignment so any help would be appreciated. I'm just trying to learn
this language.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Bulb extends JPanel
     private JButton push;
     private Circle circle, circle2;
     private final int DIAMETER = 100;
     private final int X = 10;
     private final int Y = 10;
     public Bulb()
          circle = new Circle(DIAMETER, Color.white, X,Y);
          circle2 = new Circle(DIAMETER, Color.yellow, X, Y); // to separate class
          push = new JButton("Turn on the Bulb");
          push.addActionListener(new ButtonListener());
          add(push);
          setPreferredSize(new Dimension(500, 500));
          setBackground(Color.black);
     public void paintComponent(Graphics page)
          super.paintComponent(page);
          circle.draw(page);
private class ButtonListener implements ActionListener
          public void actionPerformed(ActionEvent event) //PROBLEM AREA. I GET ERROR MESSAGE STATING
// "CANNOT FIND SYMBOL" IN REFERENCE TO VARIABLE "PAGE."
// I THOUGHT THE INNER CLASS INHERITS ALL DATA FROM
// PARENT CLASS SUCH AS "PAGE."
               circle2.draw(page);
}

There are fields, which are associated with either a class or an object (and thus live in the heap in an object on the heap), and there are local variables, which are associated with methods and threads (i.e., a method invoked within a thread, and which thus live on the stack).
They're not the same thing.
You can't use a local variable in your paintComponent method in a different method.
Anyway you're designing your class wrong. Think model-view-controller. You have the model: a bunch of state and possibly behavior that represents the thing being seen, modified, and displayed. You have the view, which is how you see the model. And you have the controller, which modifies the model.
Your event handlers are part of the controller. They should change the model.
Your paintComponent method is part of the view.
So the event handlers should change some data, e.g., add a note that a circle should be displayed.
Then your paintComponent method should look at the data and act accordingly -- e.g., see that there's a circle to be displayed, and display it.

Help , inner class included.

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