So, I'm trying to write code for a search JTextField that retrieves results from the web (kinda like Google's fancy search tips). The only problem is... probably my lack of programming experience. More specifically, I have it set up to whenever a user hits a key, it sends out a request with the JTextField input through an HttpURLConnection and retrieves the results then updates. But whenever the HttpURLConnection is running, it freezes the program for a couple seconds while it does its thing, which mainly prohibits entering in more characters into the search field if I didn't mind anything else. I've considered using separate threads, but I'm not sure how I would properly interrupt a thread and have it start over using new data while having everything else wait on it but still accepting new data. I've considered using
thread.stop();
to help manage the issue, but from what I've read, that seems taboo (am I right?). Anyways, here's pretty much what I'm using:
public class SearchField extends JTextField implements KeyListener {
public SearchField() {
addkeyListener(this);
}
public void updateData(ArrayList<String results) {
/*Pass the data off the the GUI*/
{
#Override
public void keyTyped(KeyEvent e) {
SearchQuery query = new SearchQuery(this.getText());
updateData(query.getResults());
}
}
public class SearchQuery {
ArrayList<String> results = new ArrayList<String>();
public SearchQuery(String search) {
String search_path = "http://www.whatever.com/" + search;
URL url = new URL(search_path);
conn = (HttpURLConnection) url.openConnection();
conn.addRequestProperty("User-Agent", "Mozilla/4.76");
in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
StringBuffer buf = new StringBuffer();
int i;
while((i = in.read()) != -1) {
buf.append((char) i);
}
String data = buf.toString();
parse(data);
}
public void parse(String data) {
/*Parse a bunch of JSON, return the results in an array*/
results.add(data);
}
public ArrayList<String> getResults() {
return results;
}
}
I'm just at a loss for how to synchronise recieving continuous input while getting new results for each key stroke and dismissing unfinished connections and their respective data processing when it becomes invalid at the next key stroke.
You are doing the download in the same thread that responds to user events. You need to do the download in another thread, perhaps by making SearchQuery extend Thread and doing the query in the run method. When it comes time to update the text field, you can use SwingUtilities.invokeLater to update the text field. Here’s an example:
public class SearchQuery extends Thread {
private SearchField f;
public SearchQuery(JTextField f) {
this.f = f;
}
public void run() {
// do the query here
SwingUtilities.invokeLater(new Runnable() {
public void run() {
f.updateData(results);
}
});
}
}
Then change the line:
SearchQuery query = new SearchQuery(this.getText());
to this:
SearchQuery query = new SearchQuery(this);
Related
So I'm completely lost on this one, it might be obvious solution or I'm just trying somethin that's not possible but here it is.
I have two classes one is being used as e listener class and second one is the one that handles queue(i will only include relevant code).
Handler class:
public void check() {
for (Queueable queueable : queue) {
if (!doesReceiverHavePlayers(queueable)) continue;
}
}
private boolean doesReceiverHavePlayers(Queueable queueable) {
ByteArrayDataOutput out = ByteStreams.newDataOutput();
out.writeUTF("PlayerCount");
out.writeUTF(queueable.getReceiver());
Player player = Iterables.getFirst(Bukkit.getOnlinePlayers(), null);
player.sendPluginMessage(plugin, "BungeeCord", out.toByteArray());
return /*response*/ > 0;
}
Listener class:
#Override
public void onPluginMessageReceived(String channel, #NotNull Player player, byte[] message) {
if (!channel.equals("BungeeCord")) return;
ByteArrayDataInput in = ByteStreams.newDataInput(message);
String subChannel = in.readUTF();
switch (subChannel) {
case "PlayerCount":
int response = in.readInt();
break;
}
}
The check method is called every 5 seconds and doesReceiverHavePlayers requests player count from a certain server to see if there are any players on it, but the 'response' arrives in the listener class onPluginMessageReceived method. But as you can see I'm trying to use response in the doesReceiverHavePlayers method and return boolean value. Is there any way I can achieve this and how should I do it?
In onPluginMessageReceived store the result in a ConcurrentHashMap and then lookup the value in doesReceiverHavePlayers instead of making a blocking call.
Something like this:
ConcurrentHashMap<String, Integer> playerCounts = new ConcurrentHashMap<>();
void onPluginMessageReceived() {
playerCounts.put(subChannel, response);
}
boolean doesReceiverHavePlayers() {
return playerCounts.get(queueable.getReceiver()) > 0;
}
OK so I have the uploader uploading files using the Java FTP, I would like to update the label and the progress bar. Label with the percent text, bar with the percent int value. Right now with the current code only get the 100 and full bar at the end of the upload. During the upload none of them change.
here it is:
OutputStream output = new BufferedOutputStream(ftpOut);
CopyStreamListener listener = new CopyStreamListener() {
public void bytesTransferred(long totalBytesTransferred, int bytesTransferred, long streamSize) {
System.out.printf("\r%-30S: %d / %d", "Sent", totalBytesTransferred, streamSize);
ftpup.this.upd(totalBytesTransferred,streamSize);
}
public void bytesTransferred(CopyStreamEvent arg0) { }
};
Util.copyStream(input, output, ftp.getBufferSize(), f.length(), listener);
}
public void upd(long num, long size){
int k = (int) ((num*100)/size);
System.out.println(String.valueOf(k));
this.d.setText(String.valueOf(k));
//d.setText(String.valueOf(k));
progressBar.setValue(k);
}
From the sounds of it (and lacking any evidence to the contree) it sounds like your processing a time consuming action in the Event Dispatching Thread
You might like to read Concurrency in Swing for some further insight
I'd suggest using a SwingWorker to perform the actual transfer & take advantage of its built in progress support
UPDATE after seeing source code
Don't mix heavy weight components with light weight components. Change Applet to JApplet, change TextField to JTextField, don't use Canvas use a JPanel or JComponent
If you expect other people to read your code, please use proper names for your variables, I have no idea what p is.
Your Thread is useless. Rather then starting the thread and using it's run method you simply make your download call within it's constructor. This will do nothing for you...
Remove your implementation of MyThread and replace it with
public class MyWorker extends SwingWorker<Object, Object> {
private URL host;
private File outputFile;
public MyWorker(URL host, File f) {
this.host = host;
outputFile = f;
}
#Override
protected Object doInBackground() throws Exception {
// You're ignoring the host you past in to the constructor
String hostName = "localhost";
String username = "un";
String password = "pass";
String location = f.toString();
//FTPClient ftp = null;
ftp.connect(hostName, 2121);
ftp.login(username, password);
ftp.setFileType(FTP.BINARY_FILE_TYPE);
ftp.setKeepAlive(true);
ftp.setControlKeepAliveTimeout(3000);
ftp.setDataTimeout(3000); // 100 minutes
ftp.setConnectTimeout(3000); // 100 minutes
ftp.changeWorkingDirectory("/SSL");
int reply = ftp.getReplyCode();
System.out.println("Received Reply from FTP Connection:" + reply);
if (FTPReply.isPositiveCompletion(reply)) {
System.out.println("Connected Success");
}
System.out.println(f.getName().toString());
File f1 = new File(location);
in = new FileInputStream(f1);
FileInputStream input = new FileInputStream(f1);
// ftp.storeFile(f.getName().toString(),in);
//ProgressMonitorInputStream is= new ProgressMonitorInputStream(getParent(), "st", in);
OutputStream ftpOut = ftp.storeFileStream(f.getName().toString());
System.out.println(ftpOut.toString());
//newname hereSystem.out.println(ftp.remoteRetrieve(f.toString()));
OutputStream output = new BufferedOutputStream(ftpOut);
CopyStreamListener listener = new CopyStreamListener() {
public void bytesTransferred(final long totalBytesTransferred, final int bytesTransferred, final long streamSize) {
setProgress((int) Math.round(((double) totalBytesTransferred / (double) streamSize) * 100d));
}
#Override
public void bytesTransferred(CopyStreamEvent arg0) {
// TODO Auto-generated method stub
}
};
Util.copyStream(input, output, ftp.getBufferSize(), f.length(), listener);
return null;
}
}
In your ActionListener of o (??) replace the thread execution code with
try {
MyWorker worker = new MyWorker(new URL("http://localhost"), file);
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getPropertyName().equals("progress")) {
Integer progress = (Integer) evt.getNewValue();
progressBar.setValue(progress);
}
}
});
worker.execute();
} catch (MalformedURLException ex) {
ex.printStackTrace();
}
Note. You are ignoring the URL you pass to the constructor. http:// is not ftp:// so I doubt this will work...
During the upload you don't see changes to the GUI, because you run the upload and the GUI changes in the same thread.
You should start one threayd that does the upload and another one in EDT (Event-Dispatch-Thread) that does the GUI updates.
For more info see:
The Event Dispatch Thread
You should implement the transfer logic in a SwingWorker, that way the UI will have the chance to present the progress.
I have been trying for awhile to figure out an issue with Asynchronous i/o in an android application that I am working on.
This application is required to download data to from a series of tables from Microsoft Dynamics CRM.
Once the data has been down it must preform a series of operations on the data to fill out some forms.
My problem is that I must wait for the downloads to be complete in order to start the update process.
If I add a any form of wait to my code it seems that it blocks indefinitely and never executes the callback.
I have tried methods using AtomicBooleans, AtomicIntegers, and CountDownLatchs with no success.
Here is an example using an AtomicInteger.
final CountDownLatch latch = new CountDownLatch(1);
OrganizationServiceProxy orgService;
orgService = new OrganizationServiceProxy(Constant.ENDPOINT, CRMLogin.getRequestInterceptor());
ColumnSet columnSet = new ColumnSet();
columnSet.AddColumns(AccountEntry.FETCH_COLS);
orgService.Retrieve(AccountEntry.ENTITY, UUID.fromString(accountid), columnSet, new Callback<Entity>() {
#Override
public void success(Entity entity, Response response) {
Account account = new Account();
//Load the existing fields for the account
account.load(index);
String activityid = account.getValue(AccountEntry.ACTIVITY_ID);
String recordid = account.getValue(AccountEntry.RECORD_ID);
String name = account.getValue(AccountEntry.ACCOUNT_NAME);
//Overload the fields for the account
account.load(entity);
//Reset overloaded fields on the account.
account.setValue(AccountEntry.ACTIVITY_ID, activityid);
account.setValue(AccountEntry.RECORD_ID, recordid);
account.setValue(AccountEntry.ACCOUNT_NAME, name);
//overwrite the record in the database.
account.setValue(AccountEntry.SYNCED, "1");
account.update();
Log.d("pullAccount>>>", accountid + " " + "pulled.");
latch.countDown();
}
#Override
public void failure(RetrofitError error) {
Log.d("pullAccount>>>", accountid + " " + error.getMessage());
latch.countDown();
}
});
try{
latch.await(); //THIS BLOCKS FOREVER AND EVER
}
catch (Exception e){
}
Of note is the CallBack is implemented using Retrofit.
Any guidance would be greatly appreciated.
Thank you.
Look at AsyncTask it will handle what you want in a way that Android is optimized for. There is example usage here
http://developer.android.com/reference/android/os/AsyncTask.html
EDIT:
I kinda threw this together, let me know if it works as you would expect
public class AsyncOrganizationService extends AsyncTask<Void, Void, Entity> {
#Override
protected Entity doInBackground(Void... params) {
final CountDownLatch blocker = new CountDownLatch(1);
OrganizationServiceProxy orgService;
orgService = new OrganizationServiceProxy(Constant.ENDPOINT, CRMLogin.getRequestInterceptor());
ColumnSet columnSet = new ColumnSet();
columnSet.AddColumns(AccountEntry.FETCH_COLS);
final SettableFuture<Entity> result = SettableFuture.create();
orgService.Retrieve(AccountEntry.ENTITY, UUID.fromString(accountid), columnSet, new SortedList.Callback<Entity>() {
#Override
public void success(Entity entity, HttpHelper.Response response) {
result.set(entity);
blocker.countDown();
}
});
try {
blocker.await();
return result.get();
} catch (InterruptedException | ExecutionException e) {
throw new RuntimeException(e);
}
}
#Override
protected void onPostExecute(Entity entity) {
Account account = new Account();
//Load the existing fields for the account
account.load(index);
String activityid = account.getValue(AccountEntry.ACTIVITY_ID);
String recordid = account.getValue(AccountEntry.RECORD_ID);
String name = account.getValue(AccountEntry.ACCOUNT_NAME);
//Overload the fields for the account
account.load(entity);
//Reset overloaded fields on the account.
account.setValue(AccountEntry.ACTIVITY_ID, activityid);
account.setValue(AccountEntry.RECORD_ID, recordid);
account.setValue(AccountEntry.ACCOUNT_NAME, name);
//overwrite the record in the database.
account.setValue(AccountEntry.SYNCED, "1");
account.update();
Log.d("pullAccount>>>", accountid + " " + "pulled.");
}
Im using Guava's SettableFuture class (http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/util/concurrent/SettableFuture.html). Guava is quite an amazing library - if you're not using it you should consider doing so. Otherwise, you could whip something up really quick
I have the below code where incremental command is not working as expected. I have the below radio button once it is selected I will get the value from the txt box of product and do an RPC. Based on the output I would like to form the where clause and run the resulting query.
I have the below class variables
private static boolean isLoaded = false;
StringBuilder whereClause = new StringBuilder("select * from grocery_shop where ");
StringBuilder productCode = new StringBuilder("(");
ArrayList<String> productList = null;
Below code is the place where RPC is called in Incremental command
if (Dialog.getRadioproduct().getValue()) {
DeferredCommand.addCommand(new IncrementalCommand() {
#Override
public boolean execute() {
if (isLoaded) {
ProductServiceAsync Service =
ServiceFactory.getService(ProductReportService.class);
Service.getBasicProducts(Dialog.getTxtProduct().getValue(),
new AsyncCallback<ArrayList<String>>() {
#Override
public void onServiceFailure(Throwable ex) {
showError("Error");
}
#Override
public void onServiceSuccess(ArrayList<String> result) {
productList = result;
while(productList.iterator.hasnext())
whereClause.append(" AND PROD = '" + productList.iterator.next() + "'");
isLoaded = true;
}
});
return false;
}
return true;
}
});
}
I wanted this execute query to be executed after the above RPC is success however the below line is executed before RPC.
ResultSet rs = stmt.executeQuery(whereClause);
Plz let me know if there is anything I have missed.
Well IncrementalCommand has been deprecated. Now you should use: Scheduler.RepeatingCommand or Scheduler.scheduleIncremental()
Apart from that, it is normal the execution of your query before the success answer because RPC is async (a new thread starts on that part), so, you should control your code on the onServiceSuccess and onServiceFailure (basically do the query on those methods according to your requirements).
Other option is to use the Promises pattern which is implemented on GQuery. something like
doTheRPC(...).done(...).always(...); (but if you do not have much experience on GWT the easiest solution is described above).
My problem is annoying. My server side is generating 12 random numbers (double here).
My Client side received the correct data but nothing is displayed in my Chart. That worked fine with hardcoded data in the store but not with a REST call.
The transfer between my server and my client is that :
[{"key":"key0","value":0.47222548599297787},{"key":"key1","value":0.6009173797369691},{"key":"key2","value":0.13880104282435624},{"key":"key3","value":0.01804674319345545},{"key":"key4","value":0.5547733564202956},{"key":"key5","value":0.8229999661308851},{"key":"key6","value":0.8959346004391032},{"key":"key7","value":0.6848052288628435},{"key":"key8","value":0.10222856671111813},{"key":"key9","value":0.6931371931409103},{"key":"key10","value":0.2994297934549003},{"key":"key11","value":0.47566752196381334}]
Here my simple class used for my test. I am a newbie with GXT 3
public void onModuleLoad() {
final ListStore<JSOModel> store;
final ContentPanel panel = new FramedPanel();
RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, "/ws/DocumentService/v1/test");
builder.setHeader("Accept", "application/json");
HttpProxy proxy = new HttpProxy(builder);
final Loader<ListLoadConfig, ListLoadResult<JSOModel>> loader = new ListLoader<ListLoadConfig, ListLoadResult<JSOModel>>(proxy, new DataReader<ListLoadResult<JSOModel>, String>() {
#Override
public ListLoadResult<JSOModel> read(Object loadConfig, String data) {
List<JSOModel> jsoModels = new ArrayList<JSOModel>();
JsArray<JSOModel> jsoModelJsArray = JSOModel.arrayFromJson(data);
if(jsoModelJsArray != null) {
for(int i = 0; i < jsoModelJsArray.length(); i++) {
jsoModels.add(jsoModelJsArray.get(i));
}
}
return new ListLoadResultBean<JSOModel>(jsoModels);
}
});
store = new ListStore<JSOModel>(new ModelKeyProvider<JSOModel>() {
#Override
public String getKey(JSOModel item) {
return item.get("key");
}
});
loader.addLoadHandler(new LoadResultListStoreBinding<ListLoadConfig, JSOModel, ListLoadResult<JSOModel>>(store) {
#Override
public void onLoad(LoadEvent<ListLoadConfig, ListLoadResult<JSOModel>> event) {
ListLoadResult<JSOModel> loaded = event.getLoadResult();
if(loaded.getData() == null) {
store.replaceAll(new ArrayList<JSOModel>());
} else {
store.replaceAll(loaded.getData());
}
}
});
Chart<JSOModel> chart = new Chart<JSOModel>();
chart.setStore(store);
chart.setShadowChart(true);
NumericAxis<JSOModel> axis = new NumericAxis<JSOModel>();
axis.setPosition(Chart.Position.LEFT);
axis.addField(new ValueProvider<JSOModel, Number>() {
#Override
public Number getValue(JSOModel JSOModel) {
return JSOModel.getNumber("value");
}
#Override
public void setValue(JSOModel JSOModel, Number number) {
}
#Override
public String getPath() {
return "key";
}
});
axis.setTitleConfig(new TextSprite("Number of hits"));
axis.setWidth(50);
axis.setMinimum(0);
axis.setMaximum(100);
chart.addAxis(axis);
PathSprite odd = new PathSprite();
odd.setOpacity(1);
odd.setFill(new Color("#dff"));
odd.setStroke(new Color("#aaa"));
odd.setStrokeWidth(0.5);
axis.setGridOddConfig(odd);
CategoryAxis<JSOModel, String> horizontalAxis = new CategoryAxis<JSOModel, String>();
horizontalAxis.setPosition(Chart.Position.BOTTOM);
horizontalAxis.setField(new ValueProvider<JSOModel, String>() {
#Override
public String getValue(JSOModel JSOModel) {
return JSOModel.get("key");
}
#Override
public void setValue(JSOModel JSOModel, String s) {
}
#Override
public String getPath() {
return "key";
}
});
horizontalAxis.setTitleConfig(new TextSprite("month of year"));
chart.addAxis(horizontalAxis);
LineSeries<JSOModel> column = new LineSeries<JSOModel>();
column.setYAxisPosition(Chart.Position.LEFT);
column.setStroke(new RGB(148,174,10));
column.setHighlighting(true);
chart.addSeries(column);
axis.addField(column.getYField());
chart.addSeries(column);
chart.setHeight(100);
chart.setWidth(100);
Button b = new Button("ha");
b.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent clickEvent) {
loader.load();
}
});
RootPanel.get().add(b);
panel.setCollapsible(true);
panel.setHeadingText("Column Chart");
panel.setPixelSize(620, 500);
panel.setBodyBorder(true);
VerticalLayoutContainer layout = new VerticalLayoutContainer();
panel.add(layout);
chart.setLayoutData(new VerticalLayoutContainer.VerticalLayoutData(1,1));
layout.add(chart);
chart.setBackground(new Color("#dff"));
RootPanel.get().add(panel);
There are two ways to wire the chart into a store. One is to simply specify that the chart is using a store via setStore, as you have done:
chart.setStore(store);
When you do this, you must also inform the chart when it must redraw everything - you must call:
chart.redrawChart();
This call must be made shortly after the load is completed - consider doing it at the end of onLoad.
Why is this required? In some cases, developers want to make many changes to the store, one at a time, and if the chart automatically updated after each change, that would spawn many slow changes to the data model, and could end up looking strange. In a case like this, you would only call redrawChart() after all changes were complete.
There is another option however - instead of calling setStore, you can call bindStore, and ask the Chart to automatically update whenever any change occurs to the chart:
chart.bindStore(store);
In your case, this is likely the correct answer.