Threads : wait() , notify() instead of suspend() and resume() ?
package threads.src02;
import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
publicclass Demo2extends JFrame{
privatestaticfinallong serialVersionUID = 1;
private JPanel jContentPane =null;
private JTextField jTextField =null;
private JPanel jPanel =null;
private JButton jBStart =null;
private JButton jBStop =null;
private MyThread thread =null;
public Demo2(){
super();
initialize();
}
publicstaticvoid main(String[] args){
Demo2 demo =new Demo2();
demo.setVisible(true);
}
privatevoid initialize(){
this.setSize(200, 100);
this.setContentPane(getJContentPane());
this.setTitle("JFrame");
}
private JPanel getJContentPane(){
if (jContentPane ==null){
jContentPane =new JPanel();
jContentPane.setLayout(new BorderLayout());
jContentPane.add(getJTextField(), BorderLayout.NORTH);
jContentPane.add(getJPanel(), BorderLayout.CENTER);
}
return jContentPane;
}
private JTextField getJTextField(){
if (jTextField ==null){
jTextField =new JTextField();
}
return jTextField;
}
private JPanel getJPanel(){
if (jPanel ==null){
jPanel =new JPanel();
jPanel.setLayout(new FlowLayout());
jPanel.add(getJBSart(),null);
jPanel.add(getJBStop(),null);
}
return jPanel;
}
private JButton getJBSart(){
if (jBStart ==null){
jBStart =new JButton("Start");
}
jBStart.addActionListener(new ActionListener(){
publicvoid actionPerformed(ActionEvent e){
if(thread ==null)
thread =new MyThread(Demo2.this);
else
thread.resume();
}
});
return jBStart;
}
private JButton getJBStop(){
if (jBStop ==null){
jBStop =new JButton("Stop");
}
jBStop.addActionListener(new ActionListener(){
publicvoid actionPerformed(ActionEvent e){
thread.suspend();
}
});
return jBStop;
}
publicvoid printMessage(int val){
jTextField.setText(Integer.toString(val));
}
}
class MyThreadextends Thread{
private Demo2 target;
public MyThread(Demo2 o){
this.target = o;
this.start();
}
publicvoid run(){
int i = 0;
while(true)
try{
target.printMessage(i++);
sleep(100);
}catch (InterruptedException e){
e.printStackTrace();
}
}
}
How to do the same using wait() , notify() instead of suspend(), resume() ?
[7313 byte] By [
Del2a] at [2007-11-27 0:57:10]
> How to do the same using wait() , notify() instead of suspend(),
> resume() ?
You should find information in the What should I use instead of Thread.suspend and Thread.resume? section of [url=http://java.sun.com/j2se/1.5.0/docs/guide/misc/threadPrimitiveDeprecation.html]Why Are Thread.stop, Thread.suspend, Thread.resume and Runtime.runFinalizersOnExit Deprecated?[/url]
It's so interesting but i don't see examples like my (above). Please help me remake my example.Message was edited by: Del2
Del2a at 2007-7-11 23:30:36 >
What about implementing the threadSuspended flag mechanism in your MyThread class ?
I know that I shoud use boolean flag .. I' am trying but without success give me simple example .. like mine.
Del2a at 2007-7-11 23:30:36 >
> I know that I shoud use boolean flag .. I' am trying> but without success give me simple example .. like> mine.well, you haven't got a flag anywhere
> well, you haven't got a flag anywhere
package threads.src02;
import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Demo2 extends JFrame {
private static final long serialVersionUID = 1;
private JPanel jContentPane = null;
private JTextField jTextField = null;
private JPanel jPanel = null;
private JButton jBStart = null;
private JButton jBStop = null;
private MyThread thread = null;
private boolean flag = false;
public Demo2() {
super();
initialize();
}
public static void main(String[] args) {
Demo2 demo = new Demo2();
demo.setVisible(true);
}
private void initialize() {
this.setSize(200, 100);
this.setContentPane(getJContentPane());
this.setTitle("JFrame");
}
private JPanel getJContentPane() {
if (jContentPane == null) {
jContentPane = new JPanel();
jContentPane.setLayout(new BorderLayout());
jContentPane.add(getJTextField(), BorderLayout.NORTH);
jContentPane.add(getJPanel(), BorderLayout.CENTER);
}
return jContentPane;
}
private JTextField getJTextField() {
if (jTextField == null) {
jTextField = new JTextField();
}
return jTextField;
}
private JPanel getJPanel() {
if (jPanel == null) {
jPanel = new JPanel();
jPanel.setLayout(new FlowLayout());
jPanel.add(getJBSart(), null);
jPanel.add(getJBStop(), null);
}
return jPanel;
}
private JButton getJBSart() {
if (jBStart == null) {
jBStart = new JButton("Start");
}
jBStart.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
if(thread == null)
thread = new MyThread(Demo2.this);
}
});
return jBStart;
}
private JButton getJBStop() {
if (jBStop == null) {
jBStop = new JButton("Stop");
}
jBStop.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
stop();
}
});
return jBStop;
}
synchronized public void put(int val) {
if(flag)
try {
wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
flag = false;
jTextField.setText(Integer.toString(val));
//notify();
}
synchronized public void stop(){
flag = true;
}
}
class MyThread extends Thread {
private Demo2 target;
public MyThread(Demo2 o) {
this.target = o;
this.start();
}
public void run() {
int i = 0;
while(true)
target.put(i);
}
}
Wat's wrong ?
Del2a at 2007-7-11 23:30:36 >
up!
Del2a at 2007-7-11 23:30:36 >
up!
Del2a at 2007-7-11 23:30:36 >
> Wat's wrong ?
Why didn't you implement the mechanism in your MyThread class ?
(it's the thread that is supposed to be suspended after all, not the frame, right ?)
a) Declare a boolean instance field threadSuspended
b) modify the run() method as described in the documentation from reply#1 (i.e. avoid doing anything while threadSuspended is true)
c) add a way to manage the suspended status of the thread (inspired by the doc also), something like: synchronized public void setSuspended(boolean suspended) {
threadSuspended = suspended;
if (!threadSuspended) {
notify();
}
}
Hai,
I moidfied your code and replaced suspend() and resume() with wait() and notify().
Please find the modified source below.
import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Demo2 extends JFrame {
private static final long serialVersionUID = 1;
private JPanel jContentPane = null;
private JTextField jTextField = null;
private JPanel jPanel = null;
private JButton jBStart = null;
private JButton jBStop = null;
private MyThread thread = null;
private boolean isStopFlag = false;
public Demo2() {
super();
initialize();
}
public static void main(String[] args) {
Demo2 demo = new Demo2();
demo.setVisible(true);
}
private void initialize() {
this.setSize(200, 100);
this.setContentPane(getJContentPane());
this.setTitle("JFrame");
}
private JPanel getJContentPane() {
if (jContentPane == null) {
jContentPane = new JPanel();
jContentPane.setLayout(new BorderLayout());
jContentPane.add(getJTextField(), BorderLayout.NORTH);
jContentPane.add(getJPanel(), BorderLayout.CENTER);
}
return jContentPane;
}
private JTextField getJTextField() {
if (jTextField == null) {
jTextField = new JTextField();
}
return jTextField;
}
private JPanel getJPanel() {
if (jPanel == null) {
jPanel = new JPanel();
jPanel.setLayout(new FlowLayout());
jPanel.add(getJBSart(), null);
jPanel.add(getJBStop(), null);
}
return jPanel;
}
private JButton getJBSart() {
if (jBStart == null) {
jBStart = new JButton("Start");
}
jBStart.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
if(thread == null)
thread = new MyThread(Demo2.this);
else
thread.startCounter();
}
});
return jBStart;
}
private JButton getJBStop() {
if (jBStop == null) {
jBStop = new JButton("Stop");
}
jBStop.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
isStopFlag = true;
}
});
return jBStop;
}
public void printMessage(int val) {
jTextField.setText(Integer.toString(val));
}
class MyThread extends Thread {
private Demo2 target;
public MyThread(Demo2 o) {
this.target = o;
this.start();
}
public void run() {
int i = 0;
while(true)
try {
if (isStopFlag){
synchronized(this){
wait();
isStopFlag = false;
}
}
target.printMessage(i++);
sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public void startCounter()
{
synchronized(this){
notify();
}
}
}
}
hope this might be helpful to you.
feel free to ask me if you have any doubts regarding this
pavandv.forum@gmail.com
Well the thread is a month old but you may as well get it right:
> public void actionPerformed(ActionEvent e) {
>isStopFlag = true;
> }
public void actionPerformed(ActionEvent e) {
thread.stopCounter();
}
>private boolean isStopFlag = false;
private volatile boolean isStopFlag = false;
>public void run() {
>int i = 0;
>while(true)
> try {
> if (isStopFlag){
> synchronized(this){
> wait();
> isStopFlag = false;
> }
> }
> target.printMessage(i++);
> sleep(100);
> } catch (InterruptedException e) {
> e.printStackTrace();
>}
> }
public void run() {
int i = 0;
try {
synchronized(this){
while (isStopFlag)
wait();
}
target.printMessage(i++);
sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
> public void startCounter()
> {
> synchronized(this){
> notify();
> }
> }
public void stopCounter
{
isStopFlag = true;
}
public void startCounter()
{
synchronized(this){
isStopFlag = false;
notify()All;
}
}
ejpa at 2007-7-11 23:30:36 >
