Compiling a class from another class

is it possible to compile a class from the code in another class?
i.e I want to check whether code in a .java file will compile before I use it.
Is there any methods that I could use to do this and could anyone give me advice on HOW to use the methods suggested?
thanks in advance
david

i was looking at that but it seems to only run files, not commands
is there a way to use it with command.com or cmd.exe or something to send commands to it?
also if i used a readline on an inputstream it only returned the first line (i tried running a batch file so the only line it returned was ..> javac testscript.java but i spose if i put
@echo off
javac testscript.java
if exist testscript.class (
echo compiled correctly
) else (
echo compiled incorectly
so the first line returned would either be "compiled correctly" or the compile error, but this would be compiling it to see if it compiles so im not sure if this answers the first question anyway =p

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Interacting with a compiled LABView executable from another VI

I'm using a piece of hardware that has it's driver executable written in LABView. I would like to interact with it from the inside of my own VI. There's no dedicated LABView driver and I don't have access to the source code. Communication happens over USB. The particular functionality that I need is changing one numeric control, which governs the current that's provided.
Could someone help me with this in any way?
If that matters, I'm using LV2013.

Was the exe built with VI Server/ActiveX enabled? If so, all you need is a set control value method. If your company was the one that commissioned the exe, for a small cost the vendor can enable this option and rebuild it. If you did commission it, you should have required the source code in the contract.
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Calling a method of one class from another withing the same package

hi,
i've some problem in calling a method of one class from another class within the same package.
for eg. if in Package mypack. i'm having 2 files, f1 and f2. i would like to call a method of f2 from f1(f1 is a servlet) . i donno exactly how to instantiate the object for f2. can anybody please help me in this regard.
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Problem using repaint() method from another class

I am trying to make tower of hanoi...but unable to transfer rings from a tower to another...i had made three classes....layout21 where all componentents of frame assembled and provided suitable actionlistener.....second is mainPanel which is used to draw the rods n rings in paintComponent.....and third is tower in which code for hanoi is available...i had made an object of mainPanel at layoout21 n tower but i m not able to call repaint from tower..gives an error : cannot find the symbol....method repaint in tower.
code fragments od three classes are:
LAYOUT21
class layout21 extends JFrame implements ActionListener
{ private Vector rod1 = new Vector();
private Vector rod2 = new Vector();
private Vector rod3 = new Vector();
private String elem; //comment
public String r22;
public boolean in=false;
public int count=0; //no of times the transfer to other rods performed
private int r3,rings; // current no of rings
private JComboBox nor,col;
private JLabel no;
private JLabel moved;
private JLabel no1;
private JButton start;
private JButton ref;
private AboutDialog dialog;
private JMenuItem aboutItem;
private JMenuItem exitItem;
private tower t;
final mainPanel2 p =new mainPanel2();
public layout21()
{ t = new tower();
     Toolkit kit =Toolkit.getDefaultToolkit();
Image img = kit.getImage("java.gif");
setIconImage(img);
setTitle("Tower Of Hanoi");
setSize(615,615);
setResizable(false);
setBackground(Color.CYAN);
     JMenuBar mbar = new JMenuBar();
setJMenuBar(mbar);
JMenu fileMenu = new JMenu("File");
mbar.add(fileMenu);
aboutItem = new JMenuItem("About");
aboutItem.addActionListener(this);
fileMenu.add(aboutItem);
exitItem = new JMenuItem("Exit");
exitItem.addActionListener(this);
fileMenu.add(exitItem);
Container contentPane =getContentPane();
JPanel bspanel = new JPanel();
JPanel bnpanel = new JPanel();
setBackground(Color.CYAN);
     //JComboBox
nor = new JComboBox();
nor.setEditable(false);
nor.addItem("3");
nor.addItem("4");
nor.addItem("5");
nor.addItem("6");
nor.addItem("7");
nor.addItem("8");
nor.addItem("9");
bspanel.add(nor);
col = new JComboBox();
col.setEditable(false);
col.addItem("BLACK");
col.addItem("GREEN");
col.addItem("CYAN");
bspanel.add(col);
JLabel tl = new JLabel("Time");
tl.setFont(new Font("Serif",Font.BOLD,12));
bspanel.add(tl);
JTextField tlag = new JTextField("0",4);
bspanel.add(tlag);
start =new JButton("Start");
bspanel.add(start);
ref =new JButton("Refresh");
bspanel.add(ref);
JButton end =new JButton("End");
bspanel.add(end);
start.addActionListener(this);
nor.addActionListener(this);
col.addActionListener(this);
ref.addActionListener(this);
end.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
dispose(); // Closes the dialog
contentPane.add(bspanel,BorderLayout.SOUTH);
JLabel count = new JLabel("No of Transfer reguired:");
count.setFont(new Font("Serif",Font.BOLD,16));
bnpanel.add(count);
no = new JLabel("7");
no.setFont(new Font("Serif",Font.BOLD,16));
bnpanel.add(no);
JLabel moved = new JLabel("Moved:");
moved.setFont(new Font("Serif",Font.BOLD,16));
bnpanel.add(moved);
no1 = new JLabel("0");
no1.setFont(new Font("Serif",Font.BOLD,16));
bnpanel.add(no1);
contentPane.add(bnpanel,BorderLayout.NORTH);
contentPane.add(p,BorderLayout.CENTER);
     String r = (String)nor.getSelectedItem();
rings = Integer.valueOf(r).intValue();
p.draw(rings,1) ;
public void actionPerformed(ActionEvent evt)
{ Object source = evt.getSource();
if(source == start)
r3 = Integer.valueOf((String)nor.getSelectedItem()).intValue();
p.transfer(false);
t.initialise(rod1,rod2,rod3,0);
t.towerOfHanoi(r3);
     //repaint();
     if(source == ref)
{ rod1.removeAllElements() ;
rod2.removeAllElements() ;
rod3.removeAllElements() ;
count=0;
          r3 = Integer.valueOf((String)nor.getSelectedItem()).intValue();
          p.draw(r3,1);
p.transfer(true);
no1.setText(""+0);
p.trans_vec(rod1,rod2,rod3);
t.initialise(rod1,rod2,rod3,0);
          System.out.println("");
          repaint();
if(source == nor)
{ JComboBox j = (JComboBox)source;
String item = (String)j.getSelectedItem();
int ring1 = Integer.valueOf(item).intValue();
int a=1;
for(int i=1;i<=ring1;i++)
{ a = a*2;
a=a-1;
no.setText(""+a);
p.draw(ring1,1);
repaint();
if(source == aboutItem)
{ if (dialog == null) // first time
dialog = new AboutDialog(this);
dialog.setVisible(true);
if(source == exitItem)
{ System.exit(0);
     if (source==col)
     { JComboBox j = (JComboBox)source;
String item = (String)j.getSelectedItem();
          repaint();
TOWER
class tower extends Thread
{ private Vector rod1 = new Vector();
private Vector rod2 = new Vector();
private Vector rod3 = new Vector();
private int count ;
private String elem;
final mainPanel2 z =new mainPanel2();
public void initialise(Vector r1,Vector r2,Vector r3,int c)
{ rod1 = r1;
rod2 = r2;
     rod3 = r3;
     count =c;
public void towerOfHanoi(int rings)
for(int i=0;i<rings;i++)
rod1.add(" "+(i+1));
System.out.println("rod1:"+rod1.toString());
hanoi(rings,1,2);
public void hanoi(int m,int i, int j)
if(m>0)
{ hanoi(m-1,i,6-i-j);
if(i==1 && j==2 && rod1.isEmpty()==false)
{ count++;
//no1.setText(""+count);
elem = (String)rod1.remove(0);
rod2.add(0,elem);
     //z.trans_vec(rod1,rod2,rod3);
repaint(); //NOT ABLE TO USE METHOD HERE...WHY??
//z.hanoi_paint();
try
          this.sleep(2000);
          catch (Exception e) { e.printStackTrace() ; }
System.out.println(count+". ROD 2:"+rod2.toString());
if(i==1 && j==3 && rod1.isEmpty()==false)
{ count++;
     //no1.setText(""+count);
     elem = (String)rod1.remove(0);
rod3.add(0,elem);
//z.trans_vec(rod1,rod2,rod3);
repaint();//
// z.hanoi_paint();
               try
          this.sleep(2000);
          catch (Exception e) { e.printStackTrace() ; }
System.out.println(count+". ROD 3:"+rod3.toString());
if(i==2 && j==1 && rod2.isEmpty()==false)
{ count++;
     //no1.setText(""+count);
     elem = (String)rod2.remove(0);
rod1.add(0,elem);
//z.trans_vec(rod1,rod2,rod3);
repaint();
//z.hanoi_paint();
try
          this.sleep(2000);
          catch (Exception e) { e.printStackTrace() ; }
System.out.println(count+". ROD 1:"+rod1.toString());
if(i==2 && j==3 && rod2.isEmpty()==false)
{ count++;
     //no1.setText(""+count);
     elem = (String)rod2.remove(0);
rod3.add(0,elem);
//z.trans_vec(rod1,rod2,rod3);
repaint();
//z.hanoi_paint();
try
          this.sleep(2000);
          catch (Exception e) { e.printStackTrace() ; }
System.out.println(count+". ROD 3:"+rod3.toString());
if(i==3 && j==1 && rod3.isEmpty()==false)
{ count++;
     //no1.setText(""+count);
elem = (String)rod3.remove(0);
rod1.add(0,elem);
//z.trans_vec(rod1,rod2,rod3);
repaint();
//z.hanoi_paint();
     try
          this.sleep(2000);
          catch (Exception e) { e.printStackTrace() ; }
System.out.println(count+". ROD 1:"+rod1.toString());
if(i==3 && j==2 && rod3.isEmpty()==false)
{ count++;
     //no1.setText(""+count);
elem = (String)rod3.remove(0);
rod2.add(0,elem);
//z.trans_vec(rod1,rod2,rod3);
repaint();
//z.hanoi_paint();
try
          this.sleep(2000);
          catch (Exception e) { e.printStackTrace() ; }
System.out.println(count+". ROD 2:"+rod2.toString());
hanoi(m-1,6-i-j,j);
MAINPANEL
class mainPanel2 extends JPanel //throws IOException
public Vector line = new Vector();
public Vector rod11= new Vector();
public Vector rod22= new Vector();
public Vector rod33= new Vector();
public int no_ring;
public int rod_no;
String pixel;
StringTokenizer st,st1;
int x,y;
public boolean initial =true;
public void paintComponent(Graphics g)
{ System.out.println("repaint test");
bresenham(100,60,100,360);
     bresenham(101,60,101,360);
bresenham(102,60,102,360);
bresenham(103,60,103,360);
bresenham(104,60,104,360);
g.setColor(Color.BLUE);
while(line.size()>0)
{ pixel = (String)line.remove(0);
st = new StringTokenizer(pixel);
x = Integer.valueOf(st.nextToken()).intValue();
y = Integer.valueOf(st.nextToken()).intValue();
g.drawLine(x,y,x,y);
bresenham(300,60,300,360);
bresenham(301,60,301,360);
bresenham(302,60,302,360);
bresenham(303,60,303,360);
bresenham(304,60,304,360);
while(line.size()>0)
{ pixel = (String)line.remove(0);
st = new StringTokenizer(pixel);
x = Integer.valueOf(st.nextToken()).intValue();
y = Integer.valueOf(st.nextToken()).intValue();
g.drawLine(x,y,x,y);
bresenham(500,60,500,360);
bresenham(501,60,501,360);
bresenham(502,60,502,360);
bresenham(503,60,503,360);
bresenham(504,60,504,360);
while(line.size()>0)
{ pixel = (String)line.remove(0);
st = new StringTokenizer(pixel);
x = Integer.valueOf(st.nextToken()).intValue();
y = Integer.valueOf(st.nextToken()).intValue();
g.drawLine(x,y,x,y);
bresenham(0,361,615,361);//used to get a pixel according to algo.. . func not provided
bresenham(0,362,615,362);
bresenham(0,363,615,363);
bresenham(0,364,615,364);
bresenham(0,365,615,365);
while(line.size()>0)
{ pixel = (String)line.remove(0);
st = new StringTokenizer(pixel);
x = Integer.valueOf(st.nextToken()).intValue();
y = Integer.valueOf(st.nextToken()).intValue();
g.drawLine(x,y,x,y);
if(initial==true)
g.setColor(Color.RED);
for(int i = no_ring;i>0;i--)
{ g.drawLine(100-(i*8),360-(no_ring - i)*10,100+(i*8)+5,360-(no_ring - i)*10);
g.drawLine(100-(i*8),359-(no_ring - i)*10,100+(i*8)+5,359-(no_ring - i)*10);
g.drawLine(100-(i*8),358-(no_ring - i)*10,100+(i*8)+5,358-(no_ring - i)*10);
g.drawLine(100-(i*8),357-(no_ring - i)*10,100+(i*8)+5,357-(no_ring - i)*10);
g.drawLine(100-(i*8),356-(no_ring - i)*10,100+(i*8)+5,356-(no_ring - i)*10);
// draw for each rod
//System.out.println("rod11:"+rod11);
//System.out.println("rod22:"+rod22);
//System.out.println("rod33:"+rod33);
     int r1 = rod11.size();
     int r2 = rod22.size();
     int r3 = rod33.size();
String rd1,rd2,rd3;
int r11,r12,r21,r22,r31,r32;
if(initial == false)
     { g.setColor(Color.RED);
     while(rod11.size()>0)
{ r12 = rod11.size()-1;
          rd1 = (String)rod11.remove(r12);
r11 = Integer.valueOf(rd1).intValue();
g.drawLine(100-((r11+1)*8),360-(r1 - (r11+1))*10,100+((r11+1)*8)+5,360-(r1 - (r11+1))*10);
g.drawLine(100-((r11+1)*8),359-(r1 - (r11+1))*10,100+((r11+1)*8)+5,359-(r1 - (r11+1))*10);
          g.drawLine(100-((r11+1)*8),358-(r1 - (r11+1))*10,100+((r11+1)*8)+5,358-(r1 - (r11+1))*10);
          g.drawLine(100-((r11+1)*8),357-(r1 - (r11+1))*10,100+((r11+1)*8)+5,357-(r1 - (r11+1))*10);
          g.drawLine(100-((r11+1)*8),356-(r1 - (r11+1))*10,100+((r11+1)*8)+5,356-(r1 - (r11+1))*10);
     while(rod22.size()>0)
{ g.setColor(Color.RED);
          r22 = rod22.size()-1;
     System.out.println("TEST *************************:"+r22);
          try
     // e.printStackTrace();
          InputStreamReader isr = new InputStreamReader(System.in);
     BufferedReader br = new BufferedReader(isr)      ;
     br.readLine() ;
     }catch(Exception f) {}
          rd2 = ((String)rod22.remove(r22)).trim();
r21 = Integer.valueOf(rd2).intValue();
g.drawLine(300-((r22+1)*8),360-(r2 - (r22+1))*10,300+((r22+1)*8)+5,360-(r2 - (r22+1))*10);
g.drawLine(300-((r22+1)*8),359-(r2 - (r22+1))*10,300+((r22+1)*8)+5,359-(r2 - (r22+1))*10);
          g.drawLine(300-((r22+1)*8),358-(r2 - (r22+1))*10,300+((r22+1)*8)+5,358-(r2 - (r22+1))*10);
          g.drawLine(300-((r22+1)*8),357-(r2 - (r22+1))*10,300+((r22+1)*8)+5,357-(r2 - (r22+1))*10);
          g.drawLine(300-((r22+1)*8),356-(r2 - (r22+1))*10,300+((r22+1)*8)+5,356-(r2 - (r22+1))*10);
     while(rod33.size()>0)
{ g.setColor(Color.RED);
          r32 = rod33.size()-1;
          rd3 = (String)rod33.remove(r32);
r31 = Integer.valueOf(rd3).intValue();
g.drawLine(500-((r32+1)*8),360-(r3 - (r32+1))*10,500+((r32+1)*8)+5,360-(r3 - (r32+1))*10);
g.drawLine(500-((r32+1)*8),359-(r3 - (r32+1))*10,500+((r32+1)*8)+5,359-(r3 - (r32+1))*10);
          g.drawLine(500-((r32+1)*8),358-(r3 - (r32+1))*10,500+((r32+1)*8)+5,358-(r3 - (r32+1))*10);
          g.drawLine(500-((r32+1)*8),357-(r3 - (r32+1))*10,500+((r32+1)*8)+5,357-(r3 - (r32+1))*10);
          g.drawLine(500-((r32+1)*8),356-(r3 - (r32+1))*10,500+((r32+1)*8)+5,356-(r3 - (r32+1))*10);
why i m not able to use repaint() method in tower class? from where i can use repaint() method

i can't read your code - not formatted with code tags
I have no chance of getting it to compile (AboutDialog class?? p.draw() ??)
here's a basic routine - add a couple of things to this to demonstrate what is not
being redrawn
(compare the readability of below code (using tags) to yours)
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Testing extends JFrame
public Testing()
    setSize(400,300);
    setLocation(400,300);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    final DrawPanel dp = new DrawPanel();
    JButton btn = new JButton("Change Text Location/Repaint");
    getContentPane().add(dp,BorderLayout.CENTER);
    getContentPane().add(btn,BorderLayout.SOUTH);
    btn.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent ae){
        dp.x = (int)(Math.random()*300);
        dp.y = (int)(Math.random()*150)+50;
        repaint();}});
public static void main(String[] args){new Testing().setVisible(true);}
class DrawPanel extends JPanel
int x = 50, y = 50;
public void paintComponent(Graphics g)
    super.paintComponent(g);
    g.drawString("Hello World",x,y);
}

Instantiating a class from another package

Hi,
I have two packages, say "framework" and "impl" -
framework package (framework.jar)
- contains base classes
- contains factories to instantiate concrete classes
- bundled in <product>.ear
impl package (impl.jar)
- contains implementation(concrete) classes
- compile time dependency on framework.jar
- bundled in <product>.ear
I could successfully compiled and build <product>.ear which contains both the jars. The ear gets deployed successfully.
PROBLEM
Now, whenever a factory class (part of framework package) tries to instantitate an impl class (part of impl package) using -
Class.forName(impl.ConcreteClassName OR fully_qualified_concrete_class_name).newInstance();
It throws "classNotFoundException". It is not able to locate the concrete class.
So, my question is how can i instantiate a class using its fully qualified name(package.classname) from another package ?
Thanks.

909219 wrote:
PROBLEM
Now, whenever a factory class (part of framework package) tries to instantitate an impl class (part of impl package) using -
Class.forName(impl.ConcreteClassName OR fully_qualified_concrete_class_name).newInstance();
It throws "classNotFoundException". It is not able to locate the concrete class.This sound like a classpath problem. Check your ear's manifest.
BTW:
Shouldn't the framework better use ServiceRegistry to load implementations?
bye
TPD

Drawing from another class

I have a class Score and in that lcass I have the following method:
* Draw the score to the applet windows
* @param g The graphics object
public void draw(Graphics g, int x, int y)
calculateScore();
String stringScore = new Integer(usersScore).toString();
g.drawString(stringScore, x, y);
In my Applet class, Driver, I have a global graphics object:
Graphics gObject;
I initialize it in the paint method by sayingpublic void paint(Graphics g)
gObject = g;
But, inside the Applet when I call the method draw it doesn't work.
Then I tried
gObject = getGraphics(0But that didn't work either.
Is it possible to draw to an applet from another class?
Thanks.

I just read one of you other postings on a similiar topic. In that thread everybody is assuming you are using Swing and are giving suggestions based on that assumption.
In this thread it appears you are using AWT so I gave suggestions based on that assumption.
It would be nice if you actually asked a clear question and stated what you are doing so people don't waste time guessing what the heck you are trying to do.
Thats one reason why I always ask for demo code. So we don't waste time guessing.
If you need further help then you need to create a [url http://homepage1.nifty.com/algafield/sscce.html]Short, Self Contained, Compilable and Executable, Example Program that demonstrates the incorrect behaviour, because I can't guess exactly what you are doing based on the information provided.
And don't forget to use the [url http://forum.java.sun.com/help.jspa?sec=formatting]Code Formatting Tags so the code retains its original formatting.

ANT: Include classes from another jar

Hi all.
Can I add classes from another jar to be added into my jar-file?
Other words, may I write something like this:
<target name="jar" depends="compile">
<jar destfile="deploy/my.jar"
basedir="${compile.dir}"
includes="another.jar" >
</jar>
</target>
in my build.xml?
Thanx a lot for Your tips.
Regards, Volodymyr Shram.

I've found some resolve:
<target name="jar" depends="compile">
<unjar src="another.jar" dest="another_dir"/>
<jar jarfile="deploy/my.jar">
<fileset dir="${compile.outdir}" includes="**" />
<fileset dir="another_dir" includes="**" />
</jar>
</target>
But is it only way? Can I add classes from another.jar to my.jar without extracting?
Regards, Volodymyr Shram.

Running a main Method from another class??

Hi,
I am trying to run a main method from another class, eg the main method is in Class1 and i am trying to run it from class2.
So I have
class1 c1 = new class1();
c1.main();and I get the following compilation error:
clas2.java:42: main(java.lang.String[]) in class1 cannot be applied to () c1.main();
any ideas on how to do this correctly
thanks in advance,
Donal

Hi thanks for the replies,
tried just passing a string earlier and that just gave errors too, I should have been more specific and pass a string array.
Its working now thanks again.
Donal

Instantiating an Array declared in a class from another class

Hi Guys,
I am working on a project for University and I'm stuck with this thins, which I'm sure is pretty easy when you know how...
I have a first class "Courses" in which I declare my Array, here is the code:
import java.util.*;
public class Courses
private String[][] Listing;
Courses(String[][] l)
   l = Listing;
}This class compiles just fine but I have 2 problems:
1/ Can I make sure that this array will be [3][4] ?
When I try : "private String[3][4] Listing;" or "Courses(String[3][4] l)" the class doesn't compile anymore...
FYI: I want to store the followings in my array:
French Language, 250, 130, 70
Painting, 270, 140, 70
Yoga, 250, 130, 70
2/ How can I instantiate this from another class?
From a class "Booking" I want to be able to create a new array "Listing" by calling my constructor from the Courses class and populate it with the above data (course,full-time price, part-time price, Concessions price )
How do I do that?

Thanks, I've modofied my code as follows:
import java.util.*;
public class Courses
private String[][] Listing = new String[3][4]; //create array 3 rows * 4 columns
Courses(String[][] l)
   l = Listing;
int i;
int j;
int p;
String t;
String p1;
String getTitle(int i) //return Course Title
   t=Listing[0];
return t;
int getPrice(int i, int j) //return Price (Full-Time, Part-Time, Concessions)
p1=Listing[i][j];
p=Integer.parseInt(p1);
return p;
now from my nex class Booking I want to instantiate Courses:
public class Booking
Courses c = new Courses()
}How do I actually pass the data to this...what's the syntax so that my instance will be:
c[0][0]="French Language"
c[0][1]="250"
c[0][2]="130"
c[0][3]="70"
c[1][0]="Painting"
c[1][1]="270"
c[1][2]="140"
c[1][3]="70"
c[2][0]="Yoga"
c[2][1]="250"
c[2][2]="130"
c[2][3]="70"
Thanks in advance,
Tom

Accessing a JTextField from another class

I 've got 2 classes I am trying to get the value of a JTextField that located in a second class see the code
class1 myClass = new class1();
String text = myClass.jTextField1.getText();
System.out.print(text);What happens is when i run the program and enter some text in the jTextFild1 and then click on my Jbutton it does not print anything
the JButton is in the caller class
Could anyone explains to me what is wrong

an example would help maybe....
if you want to access your jtextfield from another class then:
import javax.swing.*;
public class FieldHolderClass {
public JTextField jtf = null;
public FieldHolder() {
JFrame jf = new JFrame();
jtf = new JTextField();
jtf.setText("this is the text that is here when other callerclass seeks for text");
jf.getContentPane().add(jtf);
jf.setVisible(true);
public class CallerClass {
public static void main(String args[]) {
FieldHolderClass fHolder = new FieldHolderClass();
System.out.println((fHolder.jtf.getText());
}of course i have not written any swing app for a long time, so i might have forgotten everything... so, don't flame me when that code does not compile.
the thing that it's supposed to show, is that you make a <b>public</b> variabel (jtf) and you simply ask for it from another class by typing holderclass instances name dot and that variable name (in this case jtf) and dot and then call the method on that variable (or object...)
it might also be that you want your code to work the way that when you enter a text into jtextfield, then after pressing enter it would get printed on terminal...
in that case you should also register some Listeners... i remember that back when i was just getin' to know java then i had problems with it as well... but then again, i didn't read any manuals...
i hope i was somewhat help...

Problem getting arraylist from another class

I am trying to call information about an arraylist from another class. I am using this code to call the size of an arraylist:
import java.io.*;
public class Test
    public static void main(String argv[]) throws IOException
Echo03 thing = new Echo03();
int y=thing.value();
System.out.println(y);
Echo03 thing2 = new Echo03();
int x=thing2.percent.size();
System.out.println(x);
}from another file which starts like this:
public class Echo03 extends DefaultHandler
static ArrayList<String> percent = new ArrayList<String>();
static ArrayList<String> text = new ArrayList<String>();
int a;
public int value(){
     return percent.size();
public static void main(String argv[]) throws IOException
    {The second file is based on an example piece of code from the Java website. I havent posted the whole thing, but if it is relevant then please ask.
Anyway when I run Echo03 by itself, the arraylist has a size of 2. But when I run it from the Test file, it says a size of 0. Is this because the data is not being transferred between the classes? Or is the Echo03 program not executing (and hence the arraylist is not filling up)?
How can I fix this? I have tried 2 ways of calling the data (As seen in my Test file). Neither work.

I didnt post the full bit of the code for the second one. Here it is:
import java.io.*;
import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import java.util.ArrayList;
import java.awt.*;
import javax.swing.*;
public class Echo03 extends DefaultHandler
static ArrayList<String> percent = new ArrayList<String>();
static ArrayList<String> text = new ArrayList<String>();
int a;
public static void main(String argv[]) throws IOException
        if (argv.length != 1) {
            System.err.println("Usage: cmd filename");
            System.exit(1);
        // Use an instance of ourselves as the SAX event handler
        DefaultHandler handler = new Echo03();
        // Use the default (non-validating) parser
        SAXParserFactory factory = SAXParserFactory.newInstance();
        try {
            // Set up output stream
   out = new OutputStreamWriter(System.out, "UTF8");
            // Parse the input
            SAXParser saxParser = factory.newSAXParser();
            saxParser.parse( new File(argv[0]), handler);
for (int b=0; b<percent.size();b++){
     System.out.println(percent.get(b+1));
        } catch (Throwable t) {
        System.exit(0);
    static private Writer out;
    public void startElement(String namespaceURI,
                             String lName, // local name
                             String qName, // qualified name
                             Attributes attrs)
    throws SAXException
        if (attrs != null) {
StringBuffer sb = new StringBuffer (250);
for (int i = 0; i < attrs.getLength(); i++) {
                nl();
                emit(attrs.getValue(i));
          sb.append (attrs.getValue(i));
String sf = sb.toString ();
percent.add(sf);
System.out.println(" String: "+sf); a++;
    public void characters(char buf[], int offset, int len)
    throws SAXException
         emit(" ");
        String s = new String(buf, offset, len);
        if (!s.trim().equals("")) {text.add(s); emit(s);}
//===========================================================
    // Utility Methods ...
    //===========================================================
    // Wrap I/O exceptions in SAX exceptions, to
    // suit handler signature requirements
    private void emit(String s)
    throws SAXException
        try {
            out.write(s);
            out.flush();
        } catch (IOException e) {
            throw new SAXException("I/O error", e);
    // Start a new line
    private void nl()
    throws SAXException
        String lineEnd = System.getProperty("line.separator");
        try {
            out.write(lineEnd);
        } catch (IOException e) {
            throw new SAXException("I/O error", e);
}

How to kill one class from another class

I need to dipose one class from another class.
So that first i have to find what are all threads running in that class and then to kill them
Assist me.

Subbu_Srinivasan wrote:
I am explaining you in clear way
No you haven't been.
>
In my application i am handling many JInternalFrame.Simultaneously i am running working on more than one frame.
Due to some poor performance of some thread in one JInternalFrame,the thread is keeps on running .
i could not able to proceed further on that screen.
So i have to kill that JInternalFrame.Yoinks.
To be begin with your problem sounds like you are doing everything in one thread. So stop doing that. Second when you get it split up and if a task is taking too much time then interrupt it. No kill. Interrupt. This means the worker thread needs to check sometimes if it has been interrupted.

How to call a Java class from another java class ??

Hi ..... can somebody plz tell me
How to call a Java Class from another Java Class assuming both in the same Package??
I want to call the entire Java Class (not any specific method only........I want all the functionalities of that class)
Please provide me some slotuions!!
Waiting for some fast replies!!
Regards
Smita Mohanty

Hi Smita,
you just need to create an object of that class,thats it. Then you will be able to execute each and every method.
e.g.
you have developed A.java and B.java, both are in same package.
in implementaion of B.java
class B
            A obj = new A();
             //to access A's methods
             A.method();
            // to access A's variable
            //either
           A.variable= value.
           //or
           A.setvariable() or A.getvariable()

How to call inner class method in one java file from another java file?

hello guyz, i m tryin to access an inner class method defined in one class from another class... i m posting the code too wit error. plz help me out.
// test1.java
public class test1
     public test1()
          test t = new test();
     public class test
          test()
          public int geti()
               int i=10;
               return i;
// test2.java
class test2
     public static void main(String[] args)
          test1 t1 = new test1();
          System.out.println(t1.t.i);
i m getting error as
test2.java:7: cannot resolve symbol
symbol : variable t
location: class test1
          System.out.println(t1.t.geti());
^

There are various ways to define and use nested classes. Here is a common pattern. The inner class is private but implements an interface visible to the client. The enclosing class provides a factory method to create instances of the inner class.
interface I {
    void method();
class Outer {
    private String name;
    public Outer(String name) {
        this.name = name;
    public I createInner() {
        return new Inner();
    private class Inner implements I {
        public void method() {
            System.out.format("Enclosing object's name is %s%n", name);
public class Demo {
    public static void main(String[] args) {
        Outer outer = new Outer("Otto");
        I junior = outer.createInner();
        junior.method();
}

Getting a variable value from another class

Is there any way to get the value of a variable from another class? I have a file that calls another that does some checking then gives a true or false. The place the checking is done is inside an ActionListener I want to use that value in the file that calls the second. Any help would be great.

in 'another class', implement a method,
public boolean isCheckedOutOK( Object obj )
do the comparison in that method (use a suitable argument)

Compiling a class from another class

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