I am connected to a device using following code.
Using this socket code I cam perfom all the tasks, but now I need to perform some functions when server is going to be down. I am not able to find suitable method to do so please help.
EDIT
I want to detect when server is disconnected with this client , means after doing transactions server will be disconnected so that i can disable the buttons ,
void sendRequest(){
try {
this.clientSocket=new Socket("192.168.1.11",2000);
this.os=new DataOutputStream(this.clientSocket.getOutputStream());
this.in=new DataInputStream(this.clientSocket.getInputStream());
sendFirtCommand();
Client t=new Client();
t.start();
}catch(Exception e){
e.printStackTrace();
}
}// end of the sendRequest
My Thread code
private class Client extends Thread{
int time;
public void run(){
try{
while(true){
//if(in.read()==-1) break;
int size =in.available();
if(size>0){
byte data[]=new byte[size];
in.readFully(data);
String str=new String(data);
// System.out.println(data);
//char c[]=str.toCharArray();
str=toHex(data);
System.out.println(str);
/*
if(str.equalsIgnoreCase("050D00E7F0E1000101581D4A1D01FF")){
System.out.println("Start Left 3");
}
*/
if(str.equalsIgnoreCase("050d00e7f0e1000101601d4a1d01ff")){
stopAll();
handler.post(new Runnable() {
#Override
public void run() {
enableAll();
}
});
}
}
Try this if it helps
try{
while(true){
if(str.equalsIgnoreCase("050d00e7f0e1000101601d4a1d01ff")){
stopAll();
handler.post(new Runnable() {
#Override
public void run() {
enableAll();
}
});
}
}
}catch(IOException e)
{
handler.post(new Runnable() {
#Override
public void run() {
enableAll();
}
});
}
It seems as if Exception handling is not there in the code you have posted, let me know if i am missing something ...
Related
i am generating a random string for infinite time and setting it to a EditText.
when i was not using runOnUi app was working on newer devices which have high capability. but it crashes on older model when i start the thread and gave error(called from wrong thread exception)
Then i used runOnUi but it makes the super slow and force close it.
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
while (true) {
runOnUiThread(new Runnable() {
#Override
public void run() {
try {
tryPass.setText(getAlphaNumericString());
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
}
}
});
thread.start();
You're trying to block UI thread by calling Thread.sleep(2000); on UI thread.
Try this way:
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
while (true) {
runOnUiThread(new Runnable() {
#Override
public void run() {
tryPass.setText(getAlphaNumericString());
}
});
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
thread.start();
I have two classes, one of them is my thread in which I read outputs from a device through TCP/IP:
public static controlPanel cp = new controlPanel();
void startListenForTCP (final String ipaddress){
Thread TCPListenerThread;
TCPListenerThread = new Thread(new Runnable() {
#Override
public void run() {
Boolean run = true;
String serverMessage = null;
InetAddress serverAddr = null;
BufferedWriter out = null;
try
(Socket clientSocket = new Socket(ipaddress, 7420)) {
cp.updateGUI("Connection initiated... waiting for outputs!"+"\n");
char[] buffer = new char[2];
int charsRead = 0;
out = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));
BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
while ((charsRead = in.read(buffer)) != -1)
{
String message = new String(buffer).substring(0, charsRead);
switch (message) {
case "o,":
cp.updateGUI("Čekanje da loptica prođe RFID čitač!");
break;
case "y,":
cp.updateGUI("Hardverski problem!");
break;
case "Y,":
cp.updateGUI("Loptica nije izažla, hardverski problem!");
break;
case "I,":
cp.updateGUI("Uređaj u stanju mirovanja!!");
break;
default:
String m = message;
m = m.replaceAll("[^\\d.]", "");
try{
int i = Integer.parseInt(m);
System.out.println("Is int: "+i);
int izasao=Integer.parseInt(m);
if (redni>34){
redni=0;
}
if (izasao>0 && izasao<49){
redni =redni+1;
m=m;
ur.updateResults(redni, m);
bs.testAuto(m, redni);
System.out.println(m+ "\n");
}
} catch(NumberFormatException e){
} break;
}
}}
catch(UnknownHostException e) {
System.out.println("Unknown host..."+"\n");
} catch(IOException e) {
System.out.println("IO Error..."+"\n");
}
}
});
TCPListenerThread.start();
}
The other one is swing form in which i want to set jLabel text from the class above:
Public class controlPanel extends javax.swing.JFrame {
public static gameControler gc = new gameControler();
public controlPanel() {
initComponents();
}
public void updateGUI(final String text) {
if (!SwingUtilities.isEventDispatchThread()) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
updateGUI(text);
}
});
}jLabel5.setText(text);
System.out.println(text);
}
The message gets printed out in console but i can't set it's value to jLabel.
I need a quick way to achieve this, so any workarounds will be most helpfull.
Thank you,
Your code only updates the GUI if current thread is not the EDT:
if (!SwingUtilities.isEventDispatchThread()) {
// you call SwingUtilities.invokeLater();
}
The GUI update should also happen if the current thread happens to be the EDT. So you should change it to somehting like this:
if (SwingUtilities.isEventDispatchThread())
jLabel5.setText(text);
else
SwingUtilities.invokeLater(new Runnable() {
#Override public void run() {
jLabel5.setText(text);
}
});
Note that invokeLater() is not executed immediately but asynchronously some time later. If you need the update to happen before it returns, use SwingUtilities.invokeAndWait().
Also note that you may consider using the SwingWorker class to perform lengthy GUI-interaction tasks in a background thread.
Making it utility method
If you have to do this many times, it is profitable to make a utilitiy method for this:
public void callFromEdt(Runnable task) {
if (SwingUtilities.isEventDispatchThread())
task.run();
else
SwingUtilities.invokeLater(task); // You might want to consider
// using invokeAndWait() instead
}
I'm trying to launch multiple embedded zookeeper servers into separate threads from a Java application this way:
String port1 = "2181";
String directory1 = new File(System.getProperty("java.io.tmpdir"), "zookeeper/data1").getAbsolutePath();
final ServerConfig config1 = new ServerConfig();
config1.parse(new String[] { port1, directory1 });
new Thread(new Runnable() {
#Override
public void run()
{
try{
ZooKeeperServerMain zk = new ZooKeeperServerMain()
zk.runFromConfig(config1);
}catch(Exception e){
e.printStackTrace();
}
}
}).run();
When I start zk this way, the main process is blocked and the remaining instructions are not executed!
Is there a proper way to launch zookeeper in a separate thread?
You are calling run() instead of start() on your Thread.
new Thread(new Runnable() {
#Override
public void run()
{
try{
ZooKeeperServerMain zk = new ZooKeeperServerMain()
zk.runFromConfig(config1);
}catch(Exception e){
e.printStackTrace();
}
}
}).start();
I am writing a turn-based game on the internet. I try to pop up a window that should be in front until the input stream is ready. I created smth like this, but it seems that it does not work.
class CustomBlockerDialog extends JDialog {
/**
*
*/
private static final long serialVersionUID = 1L;
public CustomBlockerDialog(Frame owner, String text) {
super(owner, true);
setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
setSize(300, 100); // Adjust if needed
setTitle("");
add(new JLabel(text, SwingConstants.CENTER));
}
}
final CustomBlockerDialog block = new CustomBlockerDialog(null, "Not your turn");
SwingUtilities.invokeLater(new Runnable() {//A
#Override
public void run() {
System.out.println("show");
block.setVisible(true);
}
});
boolean one_write_only = true;
while(in.ready()){ /* C*/
if(one_write_only){
System.out.println("waiting server");
one_write_only = false;
}
};
System.out.println("suppose to hide");
SwingUtilities.invokeLater(new Runnable() {//B
#Override
public void run() {
System.out.println("hide");
block.setVisible(false);
}
});
It looks like "A" and "B" are executed after "C" and I have no idea why.
Your problem must be due to "C" being called on the Swing event thread and not in a background thread, since it sounds like "C" is blocking the event thread from running "A". Solution: be sure that "C" is not called on the Swing event thread. Also if this is the case, and this can be tested by running the SwingUtilities.isEventDispatchThread() method, then you don't need all those other runnables.
// note that this all must be called on the Swing event thread:
final CustomBlockerDialog block = new CustomBlockerDialog(null, "Not your turn");
System.out.println("show");
// block.setVisible(true); // !! no this will freeze!
final SwingWorker<Void, Void> worker = new SwingWorker<>() {
public void doInBackground() throws Exception {
boolean one_write_only = true;
while(in.ready()){ /* C*/
if(one_write_only){
System.out.println("waiting server");
one_write_only = false;
}
}
}
}
worker.addPropertyChangeListener(new PropertyChangeListener() {
public void propertyChanged(PropertyChangeEvent pcEvt) {
if (pcEvt.getNewValue() == SwingWorker.StateValue.DONE) {
System.out.println("hide");
block.setVisible(false);
// call worker's get() method here and catch exceptions
}
}
});
worker.execute();
// moved to down here since the dialog is modal!!!
block.setVisible(true);
Caveat: code not compiled nor tested. There may be errors present as it was typed off the cuff.
Thanks to Hovercraft Full Of Eels, I created a little different solution which works in my case:
final SwingWorker<Object,Object> worker2 = new SwingWorker<Object, Object>() {
public Object doInBackground() throws Exception {
boolean one_write_only = true;
while(!in.ready()){ /* C*/
if(one_write_only){
System.out.println("waiting server");
one_write_only = false;
}
}
return one_write_only;
}
protected void done() {
try {
block.setVisible(false);
} catch (Exception ignore) {}
}
};
worker2.execute();
block.setVisible(true);
In my GUI I have a PDF file creation operation. The operation can take up to 10-15 seconds to complete. When I start the operation, I attach a listener to it. The listener changes the cursor and disables the GUI, until the operation completes.
I would also like to add a progressbar, so the users will have a idea when it is going to complete.
Created a method startProgressBar() and called it from the start of the operation method.
See Below:
private void startSavePdfOperation() {
startProgressBar();
saveOp = new AplotSaveOperation(appReg.getString("aplot.message.SAVETOPDF"), "PDF", session);
saveOp.addOperationListener(new MyOperationListener(this) {
startProgressBar Method - See Below:
public void startProgressBar() {
Shell shell = new Shell(getShell());
shell.setSize(260, 120);
final ProgressBar bar = new ProgressBar(shell, SWT.SMOOTH);
bar.setBounds (20, 20, 200, 20);
shell.open();
final int maximum = bar.getMaximum();
new Thread(new Runnable() {
public void run() {
for (final int[] i = new int[1]; i[0] <= maximum; i[0]++) {
try {Thread.sleep (100);} catch (Throwable th) {}
if (Display.getDefault().isDisposed()) return;
Display.getDefault().asyncExec(new Runnable() {
public void run() {
if (bar.isDisposed ()) return;
bar.setSelection(i[0]);
}
});
}
}
}).start();
The code above created the ProgressBar. The issue is that the operation would end well before the progressbar indicator was close to ending.
Question: Is this because in the method I am creating a new thread and the indicator is updating according to the new thread and not the operation thread?
Question: Is it possible to create a new thread that watches the GUI thread and updates the progressbar accordingly?
Read a article suggesting using ProgressMonitorDialog with IRunnableWithProgress.
Method startProgressBar using ProgressMonitorDialog - see below:
public void startProgressBar() {
ProgressMonitorDialog dialog = new ProgressMonitorDialog(getShell());
try {
dialog.run(true, true, new IRunnableWithProgress(){
public void run(IProgressMonitor monitor) {
monitor.beginTask("Some nice progress message here ...", 100);
** getThread(); **
monitor.done();
}
});
}
catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void getThread() {
new Thread etc.. etc...
}
It seems that it will have the same issues with threading and updating as the code above.
Question: So now I am thinking can I just add or update the ProgressBar to my existing Listener
OperationListener Code - see below:
public abstract class MyOperationListener implements InterfaceAIFOperationListener {
AplotCreatePDFDialog w = null;
public MyOperationListener(AplotCreatePDFDialog win) {
w = win;
}
public void startOperation(String startMessage) {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_WAIT));
w.recursiveSetEnabled(getShell(), getShell().getEnabled());
w.getShell().setEnabled(!getShell().getEnabled());
}
});
}
public void endOperation() {
try {
endOperationImpl();
}
finally {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_ARROW));
w.recursiveSetEnabled(getShell(), true);
w.getShell().setEnabled(!getShell().getEnabled());
w.close();
}
});
}
}
abstract protected void endOperationImpl();
} // end class MyOperationListener
Thanks for any help you can give me with this.
EDIT
Baz, your answer below is exactly what the question asked, so thank you for answering.
But I am starting to think that what I am trying to do is not possible.
When my operation starts, I wanted the progress bar indicator to start and when my operation ended I wanted the indicator be at the end and the monitor would close.
I thought there might bee a way to use my listener to add the progressbar. Something like the following.
public void startOperation(String startMessage) {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
->monitor.beginTask("Creating PDF File(s)", IProgressMonitor.UNKNOWN);<-
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_WAIT));
w.recursiveSetEnabled(getShell(), getShell().getEnabled());
w.getShell().setEnabled(!getShell().getEnabled());
}
});
}
public void endOperation() {
try {
->monitor.worked(1);<-
endOperationImpl();
}
finally {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_ARROW));
w.recursiveSetEnabled(getShell(), true);
w.getShell().setEnabled(!getShell().getEnabled());
->monitor.done();<-
w.close();
}
});
}
}
abstract protected void endOperationImpl();
} // end class MyOperationListener
But I am starting to see that the ProgressBar has to have some sort of measurement to display the indicator correctly.
I would be happy if the indicator just went back and forth and the monitor would close at the end of the operation.
Why not use ProgressMonitorDialog?
Here is a related answer from me showing a simple example.
This is what it looks like:
If you are not sure about the workload, use this code:
monitor.beginTask("Copying files", IProgressMonitor.UNKNOWN);
It will show the idle bar while running.