I am trying to connect my Desktop to the PHILIPS Hue light server using java.
When the code runs, it will flow into the Controller.java. When that happens, the FindBridges method in Controller.java runs. This is where the error occurs. In debugging, it displays a NullPointerException in thread "AWT-Event-Queue-0".
I presume that the server/lightbulb cannot be found at all, even though it is turned on and my android application can connect to it.
The error is stated below:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at com.philips.lighting.gui.DesktopView$1.actionPerformed(DesktopView.java:72)
Controller.java
package com.philips.lighting;
import java.util.List;
import java.util.Random;
import javax.swing.JDialog;
import com.philips.lighting.hue.sdk.upnp.*;
import com.philips.lighting.data.HueProperties;
import com.philips.lighting.gui.AccessPointList;
import com.philips.lighting.gui.DesktopView;
import com.philips.lighting.gui.LightColoursFrame;
import com.philips.lighting.gui.PushLinkFrame;
import com.philips.lighting.hue.sdk.PHAccessPoint;
import com.philips.lighting.hue.sdk.PHBridgeSearchManager;
import com.philips.lighting.hue.sdk.PHHueSDK;
import com.philips.lighting.hue.sdk.PHMessageType;
import com.philips.lighting.hue.sdk.PHSDKListener;
import com.philips.lighting.model.PHBridge;
import com.philips.lighting.model.PHBridgeResourcesCache;
import com.philips.lighting.model.PHHueError;
import com.philips.lighting.model.PHHueParsingError;
import com.philips.lighting.model.PHLight;
import com.philips.lighting.model.PHLightState;
public class Controller {
private PHHueSDK phHueSDK;
private DesktopView desktopView;
private PushLinkFrame pushLinkDialog;
private LightColoursFrame lightColoursFrame;
private static final int MAX_HUE=65535;
private Controller instance;
public Controller(DesktopView view) {
this.desktopView = view;
this.phHueSDK = PHHueSDK.getInstance(); // or phHueSDK = PHHueSDK.getInstance();
this.instance = this;
}
public void findBridges() {
//To uniquely identify your app in the bridge whitelist we recommend you set your app name, and the device
phHueSDK.setAppName("SmartShowroomApp"); // e.g. phHueSDK.setAppName("QuickStartApp");
phHueSDK.setDeviceName("SmartDevice"); // e.g. If you are programming for Android: phHueSDK.setDeviceName(android.os.Build.MODEL);
phHueSDK = PHHueSDK.getInstance();
PHBridgeSearchManager sm = (PHBridgeSearchManager) phHueSDK.getSDKService(PHHueSDK.SEARCH_BRIDGE);
sm.search(true, true);
//This starts a UPNP/Portal Search and takes around 10 seconds.
//The PHSDKListener (onAccessPointsFound) will be notified with the bridges found.
}
private PHSDKListener listener = new PHSDKListener() {
#Override
public void onAccessPointsFound(List<PHAccessPoint> accessPointsList) {
// Handle your bridge search results here.
//Typically if multiple results are returned you will want to display them in a list
// and let the user select their bridge.
//If one is found you may opt to connect automatically to that bridge.
phHueSDK = PHHueSDK.getInstance();
desktopView.getFindingBridgeProgressBar().setVisible(false);
if (accessPointsList != null && accessPointsList.size() > 0)
{
AccessPointList accessPointList = new AccessPointList(accessPointsList, instance);
accessPointList.setVisible(true);
accessPointList.setLocationRelativeTo(null); // Centre the AccessPointList Frame
phHueSDK.getAccessPointsFound().clear(); // Clear all connected access points
phHueSDK.getAccessPointsFound().addAll(accessPointsList); // Adds multiple results to the list
}
else
{
PHBridgeSearchManager sm = (PHBridgeSearchManager) phHueSDK.getSDKService(PHHueSDK.SEARCH_BRIDGE);
sm.search(false, false, true);
}
}
#Override
public void onAuthenticationRequired(PHAccessPoint accessPoint) {
// Start the Pushlink Authentication.
phHueSDK = PHHueSDK.getInstance();
desktopView.getFindingBridgeProgressBar().setVisible(false);
phHueSDK.startPushlinkAuthentication(accessPoint);
// Arriving here indicates that Pushlinking is required (to prove the User has physical access to the bridge).
//Typically here you will display a pushlink image (with a timer) indicating to to the user they need to push the button on their bridge within 30 seconds.
pushLinkDialog = new PushLinkFrame(instance);
pushLinkDialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
pushLinkDialog.setModal(true);
pushLinkDialog.setLocationRelativeTo(null); // Center the dialog.
pushLinkDialog.setVisible(true);
}
#Override
public void onBridgeConnected(PHBridge bridge) {
phHueSDK = PHHueSDK.getInstance();
phHueSDK.setSelectedBridge(bridge);
phHueSDK.enableHeartbeat(bridge, PHHueSDK.HB_INTERVAL);
// Here it is recommended to set your connected bridge in your sdk object (as above) and start the heartbeat.
// At this point you are connected to a bridge so you should pass control to your main program/activity.
// Also it is recommended you store the connected IP Address/ Username in your app here.
//This will allow easy automatic connection on subsequent use.
// Remember to disable the heartbeat when exiting your app
//phHueSDK.disableAllHeartbeat();
//If you are only interested in a particular resource (e.g. Lights), you can enable the multi resource heartbeat as follows:
//PHHeartbeatManager heartbeatManager = PHHeartbeatManager.getInstance();
//heartbeatManager.enableLightsHeartbeat(bridge, PHHueSDK.HB_INTERVAL);
// To stop the heartbeat you can use either of the below
//heartbeatManager.disableLightsHeartbeat(bridge);
//heartbeatManager.disableAllHeartbeats(bridge);
desktopView.getFindingBridgeProgressBar().setVisible(false);
String username = HueProperties.getUsername();
String lastIpAddress = bridge.getResourceCache().getBridgeConfiguration().getIpAddress();
System.out.println("On connected: IP " + lastIpAddress);
HueProperties.storeUsername(username);
HueProperties.storeLastIPAddress(lastIpAddress);
HueProperties.saveProperties();
// Update the GUI.
desktopView.getLastConnectedIP().setText(lastIpAddress);
desktopView.getLastUserName().setText(username);
// Close the PushLink dialog (if it is showing).
if (pushLinkDialog!=null && pushLinkDialog.isShowing()) {
pushLinkDialog.setVisible(false);
}
// Enable the Buttons/Controls to change the hue bulbs.s
desktopView.getRandomLightsButton().setEnabled(true);
desktopView.getSetLightsButton().setEnabled(true);
}
#Override
public void onCacheUpdated(List cacheNotificationsList, PHBridge bridge) {
// Here you receive notifications that the BridgeResource Cache was updated. Use the PHMessageType to
// check which cache was updated, e.g.
if (cacheNotificationsList.contains(PHMessageType.LIGHTS_CACHE_UPDATED)) {
System.out.println("Lights Cache Updated ");
}
}
#Override
public void onConnectionLost(PHAccessPoint accessPoint) {
// Here you would handle the loss of connection to your bridge.
phHueSDK = PHHueSDK.getInstance();
if (accessPoint == null)
{
System.out.println("Please reconnect to your bridge.");
}
}
#Override
public void onConnectionResumed(PHBridge bridge) {
PHHueSDK phHueSDK = PHHueSDK.getInstance();
for (int i = 0; i < phHueSDK.getDisconnectedAccessPoint().size(); i++)
{
if (phHueSDK.getDisconnectedAccessPoint().get(i).getIpAddress()
.equals(bridge.getResourceCache().getBridgeConfiguration().getIpAddress())) {
phHueSDK.getDisconnectedAccessPoint().remove(i);
}
}
}
#Override
public void onError(int code, final String message) {
// Here you can handle events such as Bridge Not Responding, Authentication Failed and Bridge Not Found.
if (code == PHHueError.BRIDGE_NOT_RESPONDING) {
desktopView.getFindingBridgeProgressBar().setVisible(false);
desktopView.getFindBridgesButton().setEnabled(true);
desktopView.getConnectToLastBridgeButton().setEnabled(true);
desktopView.showDialog(message);
}
else if (code == PHMessageType.PUSHLINK_BUTTON_NOT_PRESSED) {
pushLinkDialog.incrementProgress();
}
else if (code == PHMessageType.PUSHLINK_AUTHENTICATION_FAILED) {
if (pushLinkDialog.isShowing()) {
pushLinkDialog.setVisible(false);
desktopView.showDialog(message);
}
else {
desktopView.showDialog(message);
}
desktopView.getFindBridgesButton().setEnabled(true);
}
else if (code == PHMessageType.BRIDGE_NOT_FOUND) {
desktopView.getFindingBridgeProgressBar().setVisible(false);
desktopView.getFindBridgesButton().setEnabled(true);
desktopView.showDialog(message);
}
}
#Override
public void onParsingErrors(List<PHHueParsingError> parsingErrorsList) {
// Any JSON parsing errors are returned here.
//Typically your program should never return these.
for (PHHueParsingError parsingError: parsingErrorsList) {
System.out.println("ParsingError : " + parsingError.getMessage());
}
}
};
public PHSDKListener getListener() {
return listener;
}
public void setListener(PHSDKListener listener) {
this.listener = listener;
}
public void randomLights() {
PHBridge bridge = phHueSDK.getSelectedBridge();
PHBridgeResourcesCache cache = bridge.getResourceCache();
// And now you can get any resource you want, for example:
List<PHLight> allLights = cache.getAllLights();
Random rand = new Random();
for (PHLight light : allLights) {
PHLightState lightState = new PHLightState();
lightState.setHue(rand.nextInt(MAX_HUE));
bridge.updateLightState(light, lightState); // If no bridge response is required then use this simpler form.
}
}
public void showControlLightsWindow() {
if (lightColoursFrame == null) {
lightColoursFrame = new LightColoursFrame();
}
lightColoursFrame.setLocationRelativeTo(null); // Centre window
lightColoursFrame.setVisible(true);
}
/**
* Connect to the last known access point.
* This method is triggered by the Connect to Bridge button but it can equally be used to automatically connect to a bridge.
*
*/
public boolean connectToLastKnownAccessPoint() {
String username = HueProperties.getUsername();
String lastIpAddress = HueProperties.getLastConnectedIP();
if (username==null || lastIpAddress == null) {
desktopView.showDialog("Missing Last Username or Last IP. Last known connection not found.");
return false;
}
//Obviously, every time a user opens up their Android hue app or application you don't want them to have to select their bridge, authenticate pushlink everytime.
//The recommended way to overcome this issue is to store the connected IP Address/Username (using your preferred method storage) and if set try to connect automatically.
PHAccessPoint accessPoint = new PHAccessPoint();
accessPoint.setIpAddress(lastIpAddress);
accessPoint.setUsername(username);
phHueSDK.connect(accessPoint);
return true;
//Note that the .connect method returns control to your PHSDKListener, so when connected the onBridgeConnected will be called again, and if your users Bridge IP has changed for example, onError will be called and can be handled programatically.
}
public void enableFindBridgesButton() {
desktopView.getFindBridgesButton().setEnabled(true);
}
public void showProgressBar() {
desktopView.getFindingBridgeProgressBar().setVisible(true);
}
}
DesktopView.java
package com.philips.lighting.gui;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JTextField;
import layout.TableLayout;
import com.philips.lighting.Controller;
import com.philips.lighting.data.HueProperties;
/**
* DesktopView.java
*
* The main GUI showing last connected IP/Username and buttons for Finding Bridges and Changing the Hue Lights, once connected to a bridge.
*
*/
public class DesktopView extends JFrame {
private static final long serialVersionUID = -7469471678945429320L;
private Controller controller;
private JButton setLightsButton;
private JButton randomLightsButton;
private JButton findBridgesButton;
private JButton connectToLastBridgeButton;
private JProgressBar findingBridgeProgressBar;
private JTextField lastConnectedIP;
private JTextField lastUserName;
public DesktopView(){
setTitle("Hue Desktop");
JPanel mainPanel = new JPanel();
// TODO - Move to another class
JPanel controls = new JPanel();
controls.setLayout(new GridLayout(2,3));
findingBridgeProgressBar = new JProgressBar();
findingBridgeProgressBar.setBorderPainted(false);
findingBridgeProgressBar.setIndeterminate(true);
findingBridgeProgressBar.setVisible(false);
//Set up components preferred size
String lastUsername = HueProperties.getUsername();
String lastConnectedIPStr = HueProperties.getLastConnectedIP();
JLabel labelLastConIP = new JLabel("Last Connected IP:");
lastConnectedIP = new JTextField(lastConnectedIPStr);
lastConnectedIP.setEditable(false);
JLabel labelLastUsername = new JLabel("Last UserName:");
lastUserName = new JTextField(lastUsername);
lastUserName.setEditable(false);
findBridgesButton = new JButton("Find New Bridges");
findBridgesButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
findBridgesButton.setEnabled(false);
connectToLastBridgeButton.setEnabled(false);
controller.findBridges();
findingBridgeProgressBar.setBorderPainted(true);
findingBridgeProgressBar.setVisible(true);
}
});
connectToLastBridgeButton = new JButton("Auto Connect");
connectToLastBridgeButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
if (controller.connectToLastKnownAccessPoint()) {
connectToLastBridgeButton.setEnabled(false);
findBridgesButton.setEnabled(false);
findingBridgeProgressBar.setBorderPainted(true);
findingBridgeProgressBar.setVisible(true);
}
}
});
setLightsButton = new JButton("Change Light Colours");
setLightsButton.setEnabled(false);
setLightsButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
controller.showControlLightsWindow();
}
});
randomLightsButton = new JButton("Randomize Lights");
randomLightsButton.setEnabled(false);
randomLightsButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
controller.randomLights();
}
});
double border = 10;
double size[][] =
{{border, 160, 20, 300, 20, 160}, // Columns
{border, 26, 10, 26, 26, 26,6,26}}; // Rows
mainPanel.setLayout (new TableLayout(size));
mainPanel.add(labelLastConIP, " 1, 1");
mainPanel.add(lastConnectedIP, " 3, 1");
mainPanel.add(labelLastUsername, " 1, 3");
mainPanel.add(lastUserName, " 3, 3");
mainPanel.add(findingBridgeProgressBar, " 3, 5");
mainPanel.add(connectToLastBridgeButton, " 5, 1");
mainPanel.add(findBridgesButton, " 5, 3");
mainPanel.add(randomLightsButton, " 5, 5");
mainPanel.add(setLightsButton, " 5, 7");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setPreferredSize(new Dimension(700,270));
getContentPane().add(new JLabel(" An example Java/Swing Desktop Application to control your Hue Lights."), BorderLayout.NORTH);
getContentPane().add(mainPanel, BorderLayout.CENTER);
//4. Size the frame.
pack();
setLocationRelativeTo(null); // Centre the window.
setVisible(true);
}
public void setController(Controller controller) {
this.controller = controller;
}
public JButton getSetLightsButton() {
return setLightsButton;
}
public JButton getRandomLightsButton() {
return randomLightsButton;
}
public JButton getFindBridgesButton() {
return findBridgesButton;
}
public JButton getConnectToLastBridgeButton() {
return connectToLastBridgeButton;
}
public void showDialog(String message) {
JOptionPane.showMessageDialog(this, message);
}
public JProgressBar getFindingBridgeProgressBar() {
return findingBridgeProgressBar;
}
public JTextField getLastConnectedIP() {
return lastConnectedIP;
}
public JTextField getLastUserName() {
return lastUserName;
}
}
HueDesktop.java
package com.philips.lighting;
import com.philips.lighting.data.HueProperties;
import com.philips.lighting.gui.DesktopView;
import com.philips.lighting.hue.sdk.PHHueSDK;
/**
* HueDesktop.java
* An example Java/Swing Desktop application illustrating how to connect to a bridge and change your Hue lights
* using a Java Desktop Application.
*
* For more information on programming for Hue see:
* http://developers.meethue.com
*
*/
class HueDesktop {
public static void main(String args[]) {
new HueDesktop();
}
public HueDesktop() {
PHHueSDK phHueSDK = PHHueSDK.create();
// Load in HueProperties, if first time use a properties file is created.
HueProperties.loadProperties();
// Set Up the View (A JFrame, MenuBar and Console).
DesktopView desktopView = new DesktopView();
// Bind the Model and View
Controller controller = new Controller(desktopView);
desktopView.setController(controller);
// Register the PHSDKListener to receive callbacks from the bridge.
phHueSDK.getNotificationManager().registerSDKListener(controller.getListener());
}
}
Did you ever solve this? In future it is probably best to post hue Java SDK issues on the GitHub site. https://github.com/PhilipsHue/PhilipsHueSDK-Java-MultiPlatform-Android/issues
I would have seen this sooner on here (I wrote this code btw so am possibly the culprit).
I do remember seeing a similar issue before, am pretty sure it was related to Macs and the JDK Compiler level used (I possibly used an incompatible Swing component on Mac and JDK 1.6). Can you let me know your OS and JDK Compiler level and I will check this further?
Related
I am trying to implement the Apache Configuration 2 in my codebase
import java.io.File;
import java.util.concurrent.TimeUnit;
import org.apache.commons.configuration2.PropertiesConfiguration;
import org.apache.commons.configuration2.builder.ConfigurationBuilderEvent;
import org.apache.commons.configuration2.builder.ReloadingFileBasedConfigurationBuilder;
import org.apache.commons.configuration2.builder.fluent.Parameters;
import org.apache.commons.configuration2.convert.DefaultListDelimiterHandler;
import org.apache.commons.configuration2.event.EventListener;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.configuration2.reloading.PeriodicReloadingTrigger;
import org.apache.commons.configuration2.CompositeConfiguration;
public class Test {
private static final long DELAY_MILLIS = 10 * 60 * 5;
public static void main(String[] args) {
// TODO Auto-generated method stub
CompositeConfiguration compositeConfiguration = new CompositeConfiguration();
PropertiesConfiguration props = null;
try {
props = initPropertiesConfiguration(new File("/tmp/DEV.properties"));
} catch (ConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
compositeConfiguration.addConfiguration( props );
compositeConfiguration.addEventListener(ConfigurationBuilderEvent.ANY,
new EventListener<ConfigurationBuilderEvent>()
{
#Override
public void onEvent(ConfigurationBuilderEvent event)
{
System.out.println("Event:" + event);
}
});
System.out.println(compositeConfiguration.getString("property1"));
try {
Thread.sleep(14*1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// Have a script which changes the value of property1 in DEV.properties
System.out.println(compositeConfiguration.getString("property1"));
}
protected static PropertiesConfiguration initPropertiesConfiguration(File propsFile) throws ConfigurationException {
if(propsFile.exists()) {
final ReloadingFileBasedConfigurationBuilder<PropertiesConfiguration> builder =
new ReloadingFileBasedConfigurationBuilder<PropertiesConfiguration>(PropertiesConfiguration.class)
.configure(new Parameters().fileBased()
.setFile(propsFile)
.setReloadingRefreshDelay(DELAY_MILLIS)
.setThrowExceptionOnMissing(false)
.setListDelimiterHandler(new DefaultListDelimiterHandler(';')));
final PropertiesConfiguration propsConfiguration = builder.getConfiguration();
PeriodicReloadingTrigger trigger = new PeriodicReloadingTrigger(builder.getReloadingController(),
null, 1, TimeUnit.SECONDS);
trigger.start();
return propsConfiguration;
} else {
return new PropertiesConfiguration();
}
}
}
Here is a sample code that I using to check whether the Automatic Reloading works or not. However when the underlying property file is updated, the configuration doesn't reflect it.
As per the documentation :
One important point to keep in mind when using this approach to reloading is that reloads are only functional if the builder is used as central component for accessing configuration data. The configuration instance obtained from the builder will not change automagically! So if an application fetches a configuration object from the builder at startup and then uses it throughout its life time, changes on the external configuration file become never visible. The correct approach is to keep a reference to the builder centrally and obtain the configuration from there every time configuration data is needed.
https://commons.apache.org/proper/commons-configuration/userguide/howto_reloading.html#Reloading_File-based_Configurations
This is different from what the old implementation was.
I was able to successfully execute your sample code by making 2 changes :
make the builder available globally and access the configuration from the builder :
System.out.println(builder.getConfiguration().getString("property1"));
add the listener to the builder :
`builder.addEventListener(ConfigurationBuilderEvent.ANY, new EventListener() {
public void onEvent(ConfigurationBuilderEvent event) {
System.out.println("Event:" + event);
}
});
Posting my sample program, where I was able to successfully demonstrate it
import java.io.File;
import java.util.concurrent.TimeUnit;
import org.apache.commons.configuration2.PropertiesConfiguration;
import org.apache.commons.configuration2.builder.ConfigurationBuilderEvent;
import org.apache.commons.configuration2.builder.ReloadingFileBasedConfigurationBuilder;
import org.apache.commons.configuration2.builder.fluent.Parameters;
import org.apache.commons.configuration2.event.EventListener;
import org.apache.commons.configuration2.reloading.PeriodicReloadingTrigger;
public class TestDynamicProps {
public static void main(String[] args) throws Exception {
Parameters params = new Parameters();
ReloadingFileBasedConfigurationBuilder<PropertiesConfiguration> builder =
new ReloadingFileBasedConfigurationBuilder<PropertiesConfiguration>(PropertiesConfiguration.class)
.configure(params.fileBased()
.setFile(new File("src/main/resources/override.properties")));
PeriodicReloadingTrigger trigger = new PeriodicReloadingTrigger(builder.getReloadingController(),
null, 1, TimeUnit.SECONDS);
trigger.start();
builder.addEventListener(ConfigurationBuilderEvent.ANY, new EventListener<ConfigurationBuilderEvent>() {
public void onEvent(ConfigurationBuilderEvent event) {
System.out.println("Event:" + event);
}
});
while (true) {
Thread.sleep(1000);
System.out.println(builder.getConfiguration().getString("property1"));
}
}
}
The problem with your implementation is, that the reloading is done on the ReloadingFileBasedConfigurationBuilder Object and is not being returned to the PropertiesConfiguration Object.
I thought this would be a simple question but I am having trouble finding an answer. I have a single ImageView object associated with a JavaFX Scene object and I want to load large images in from disk and display them in sequence one after another using the ImageView. I have been trying to find a good way to repeatedly check the Image object and when it is done loading in the background set it to the ImageView and then start loading a new Image object. The code I have come up with (below) works sometimes and sometimes it doesn't. I am pretty sure I am running into issues with JavaFX and threads. It loads the first image sometimes and stops. The variable "processing" is a boolean instance variable in the class.
What is the proper way to load an image in JavaFX in the background and set it to the ImageView after it is done loading?
public void start(Stage primaryStage) {
...
ImageView view = new ImageView();
((Group)scene.getRoot()).getChildren().add(view);
...
Thread th = new Thread(new Thread() {
public void run() {
while(true) {
if (!processing) {
processing = true;
String filename = files[count].toURI().toString();
Image image = new Image(filename,true);
image.progressProperty().addListener(new ChangeListener<Number>() {
#Override public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number progress) {
if ((Double) progress == 1.0) {
if (! image.isError()) {
view.setImage(image);
}
count++;
if (count == files.length) {
count = 0;
}
processing = false;
}
}
});
}
}
}
});
}
I actually think there's probably a better general approach to satisfying whatever your application's requirements are than the approach you are trying to use, but here is my best answer at implementing the approach you describe.
Create a bounded BlockingQueue to hold the images as you load them. The size of the queue may need some tuning: too small and you won't have any "buffer" (so you won't be able to take advantage of any that are faster to load than the average), too large and you might consume too much memory. The BlockingQueue allows you to access it safely from multiple threads.
Create a thread that simply loops and loads each image synchronously, i.e. that thread blocks while each image loads, and deposits them in the BlockingQueue.
Since you want to try to display images up to once per FX frame (i.e. 60fps), use an AnimationTimer. This has a handle method that is invoked on each frame render, on the FX Application Thread, so you can implement it just to poll() the BlockingQueue, and if an image was available, set it in the ImageView.
Here's an SSCCE. I also indicated how to do this where you display each image for a fixed amount of time, as I think that's a more common use case and might help others looking for similar functionality.
import java.io.File;
import java.net.MalformedURLException;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import javafx.animation.AnimationTimer;
import javafx.animation.PauseTransition;
import javafx.application.Application;
import javafx.concurrent.Task;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.StackPane;
import javafx.stage.DirectoryChooser;
import javafx.stage.Stage;
public class ScreenSaver extends Application {
#Override
public void start(Stage primaryStage) {
BorderPane root = new BorderPane();
Button startButton = new Button("Choose image directory...");
startButton.setOnAction(e -> {
DirectoryChooser chooser= new DirectoryChooser();
File dir = chooser.showDialog(primaryStage);
if (dir != null) {
File[] files = Stream.of(dir.listFiles()).filter(file -> {
String fName = file.getAbsolutePath().toLowerCase();
return fName.endsWith(".jpeg") | fName.endsWith(".jpg") | fName.endsWith(".png");
}).collect(Collectors.toList()).toArray(new File[0]);
root.setCenter(createScreenSaver(files));
}
});
root.setCenter(new StackPane(startButton));
primaryStage.setScene(new Scene(root, 800, 800));
primaryStage.show();
}
private Parent createScreenSaver(File[] files) {
ImageView imageView = new ImageView();
Pane pane = new Pane(imageView);
imageView.fitWidthProperty().bind(pane.widthProperty());
imageView.fitHeightProperty().bind(pane.heightProperty());
imageView.setPreserveRatio(true);
Executor exec = Executors.newCachedThreadPool(runnable -> {
Thread t = new Thread(runnable);
t.setDaemon(true);
return t ;
});
final int imageBufferSize = 5 ;
BlockingQueue<Image> imageQueue = new ArrayBlockingQueue<Image>(imageBufferSize);
exec.execute(() -> {
int index = 0 ;
try {
while (true) {
Image image = new Image(files[index].toURI().toURL().toExternalForm(), false);
imageQueue.put(image);
index = (index + 1) % files.length ;
}
} catch (MalformedURLException e) {
throw new RuntimeException(e);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
});
// This will show a new image every single rendering frame, if one is available:
AnimationTimer timer = new AnimationTimer() {
#Override
public void handle(long now) {
Image image = imageQueue.poll();
if (image != null) {
imageView.setImage(image);
}
}
};
timer.start();
// This wait for an image to become available, then show it for a fixed amount of time,
// before attempting to load the next one:
// Duration displayTime = Duration.seconds(1);
// PauseTransition pause = new PauseTransition(displayTime);
// pause.setOnFinished(e -> exec.execute(createImageDisplayTask(pause, imageQueue, imageView)));
// exec.execute(createImageDisplayTask(pause, imageQueue, imageView));
return pane ;
}
private Task<Image> createImageDisplayTask(PauseTransition pause, BlockingQueue<Image> imageQueue, ImageView imageView) {
Task<Image> imageDisplayTask = new Task<Image>() {
#Override
public Image call() throws InterruptedException {
return imageQueue.take();
}
};
imageDisplayTask.setOnSucceeded(e -> {
imageView.setImage(imageDisplayTask.getValue());
pause.playFromStart();
});
return imageDisplayTask ;
}
public static void main(String[] args) {
launch(args);
}
}
I am working on a j2me application which contain a class to find the location of mobile using GPS.I need to include gauge while the location provider API is called and it finds the location.I am new to j2me so still not clear with all the concepts.I am pasting my code below.Please help me through this.Thanks in advance..
package org.ets.utils;
import javax.microedition.lcdui.*;
import javax.microedition.location.*;
import javax.microedition.io.*;
import java.io.*;
import org.ets.midlet.ETS_infozech;
import javax.microedition.midlet.*;
public class Locfinder {
public Locfinder(ETS_infozech midlet)
{
this.midlet = midlet;
}
public static String ex()
{
try {
checkLocation();
} catch (Exception ex)
{
ex.printStackTrace();
}
//System.out.println(string);
return string;
}
public static void checkLocation() throws Exception
{
Location l;
LocationProvider lp;
Coordinates c;
// Set criteria for selecting a location provider:
// accurate to 500 meters horizontally
Criteria cr= new Criteria();
cr.setHorizontalAccuracy(500);
// Get an instance of the provider
lp= LocationProvider.getInstance(cr);
//Request the location, setting a one-minute timeout
l = lp.getLocation(60);
c = l.getQualifiedCoordinates();
if(c != null ) {
// Use coordinate information
double lat = c.getLatitude();
double lon = c.getLongitude();
string = " LAT-" + lat + " LONG-" + lon;
}
}
}
There's no way you can link a Gauge to some task.
You have to set values to the Gauge manually. So you'd create a Gauge and add it to your Form. Then start your code to perform the look-up.
In between your lines of code, you'd add myGauge.setValue(some_value); to increase the indicator.
Of course, this becomes difficult when most of the task is contained in a single line of code, like e.g. lp.getLocation(60);.
I think, in that case, I would create a Thread that automatically increases the value on the Gauge in the 60 seconds, but can be stopped/overridden by a manual setting.
class Autoincrementer implements Runnable {
private boolean running;
private Gauge gauge;
private int seconds;
private int secondsElapsed;
public Autoincrementer(Gauge gauge) {
this.gauge = gauge;
this.seconds = gauge.getMaxValue();
this.running = true;
this.secondsElapsed = 0;
}
public void run() {
if (running) {
secondsElapsed++;
gauge.setValue(secondsElapsed);
if (secondsElapsed>=gauge.getMaxValue()) running = false; // Stop the auto incrementing
try {
Thread.sleep(1000); // Sleep for 1 second
} catch (Exception e) {}
}
}
public void stop() {
running = false;
}
}
You would then create a Gauge and add it to your Form
myGauge = new Gauge("Process", false, 60, 0);
myForm.append(myGauge);
Then start the auto-increment.
myIncrementer = new Autoincrementer(myGauge);
new Thread(myIncrementer).start();
And then call your look-up code.
checkLocation();
Inside your look-up code, add code to stop the auto-incrementing and set the Gauge object to 100%, if the look-up was successful (meaning before the timeout).
myIncrementer.stop();
myGauge.setValue(60);
LWUIT 1.5 can help you in this. Am not sure for Location API which you are using.
But you will get Gauge using LWUIT 1.5. Use Lwuit instead of LCDUI.
http://www.oracle.com/technetwork/java/javame/javamobile/download/lwuit/index.html
I have an Xpage page with a single Notes document datasource.
After saving a document I want to (conditionally) trigger an agent. The agent takes some time to process and we don't want the user to have to wait for the result, so it should be executed asynchronously.
I've managed to get it working from client side JS by using an XHR to the agent URL, but I would like to do it server side so I can control the "Next page" better. When using .run() or .runonserver() the client waits till the agent completes.
Any idea how I could trigger an agent (from SSJS) on PostSaveDocument without the client waiting for the result?
Try to look at Thread and Jobs application on OpenNTF.org. There are nice demos of running task in background, check it here
As Martin suggested I used the JobScheduler example on OpenNtf and modified it to suit my needs. Resulting code can be found below. Any comments or improvements are welcome.
import java.security.AccessController;
import java.security.PrivilegedAction;
import lotus.domino.Agent;
import lotus.domino.Database;
import lotus.domino.NotesException;
import lotus.domino.Session;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.IJobChangeEvent;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.core.runtime.jobs.JobChangeAdapter;
import com.ibm.domino.xsp.module.nsf.ThreadSessionExecutor;
public class JobRunner {
public static void start(String dbPath, String agentName, String paramDocId) {
synchronized (JobRunner.class) {
runningJob = new ISPJob(dbPath, agentName, paramDocId);
runningJob.addJobChangeListener(new JobChangeAdapter() {
public void done(IJobChangeEvent event) {
System.out.println("Done event");
runningJob = null;
}
});
AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
runningJob.schedule();
return null;
}
});
}
}
private static ISPJob runningJob;
private static final class ISPJob extends Job {
private ThreadSessionExecutor<IStatus> executor;
private String docId;
private String dbPath;
private String agentName;
public ISPJob(String paramDbPath, String paramAgentName, String paramDocId) {
super(paramDocId);
this.docId = paramDocId;
this.dbPath = paramDbPath;
this.agentName = paramAgentName;
this.executor = new ThreadSessionExecutor<IStatus>() {
#Override
protected IStatus run(Session session) throws NotesException {
System.out.println("Job started" + docId);
System.out.println(" >> Session created: "
+ session.getUserName() + ", Effective User:"
+ session.getEffectiveUserName());
Database db = session.getDatabase(null,dbPath);
if (db != null) {
try {
if (!db.isOpen()) db.open();
if (db.isOpen()) {
System.out.println(" >> Database opened: "
+ db.getTitle());
Agent agent = db.getAgent(agentName);
try {
System.out.println(" >> Agent Started: " + agent.getName());
agent.run(docId);
System.out.println(" >> Agent Ran: " + agent.getName());
} finally {
agent.recycle();
}
}
} finally {
db.recycle();
}
}
System.out.println("Job completed");
return Status.OK_STATUS;
}
};
}
protected IStatus run(IProgressMonitor monitor) {
try {
return executor.run();
} catch (Exception ex) {
return Status.CANCEL_STATUS;
}
}
};
}
You could use a session bean (so it won't get destroyed) that kicks off an Java thread. Or you could issue in code a server console command. Or you implement a DOTS listener.
This may/may not be an option depending on your application requirements but I am having good success calling function in the onClientLoad event which essentially kicks off the process after the XPage has fully loaded.
I develop simple j2me bluetooth client and have problem with bluetooth device search.
Function startInquiry nothing found.
Client : nokia 5220
Server : my pc with bluetooth adapter
All bluetooth devices is on.
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import javax.microedition.midlet.*;
import javax.bluetooth.*;
import java.util.Vector;
import javax.microedition.lcdui.*;
/**
* #author Администратор
*/
public class Midlet extends MIDlet implements DiscoveryListener
{
private static Vector vecDevices=new Vector();
private static String connectionURL=null;
private LocalDevice localDevice;
private DiscoveryAgent agent;
private RemoteDevice remoteDevice;
private RemoteDevice[] devList;
private Display display;
private Form form;
public void startApp() {
display = Display.getDisplay(this);
form = new Form( "Client" );
try {
localDevice = LocalDevice.getLocalDevice();
} catch( BluetoothStateException e ) {
e.printStackTrace();
}
form.append("Address: "+localDevice.getBluetoothAddress()+"\n\n");
form.append("Name: "+localDevice.getFriendlyName()+"\n\n");
try {
agent = localDevice.getLocalDevice().getDiscoveryAgent();
form.append("Starting device inquiry... \n\n");
boolean si = agent.startInquiry(DiscoveryAgent.GIAC, this);
if ( si ) {
form.append("true");
} else {
form.append("false");
}
} catch( BluetoothStateException e ) {
}
int deviceCount = vecDevices.size();
if(deviceCount <= 0){
form.append("No Devices Found .");
}
else{
//print bluetooth device addresses and names in the format [ No. address (name) ]
form.append("Bluetooth Devices: ");
for (int i = 0; i < deviceCount; i++) {
remoteDevice=(RemoteDevice)vecDevices.elementAt(i);
form.append( remoteDevice.getBluetoothAddress() );
}
}
display.setCurrent(form);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
public void deviceDiscovered(RemoteDevice btDevice, DeviceClass cod) {
//add the device to the vector
if(!vecDevices.contains(btDevice)){
vecDevices.addElement(btDevice);
}
}
public void inquiryCompleted(int discType)
{
}
//implement this method since services are not being discovered
public void servicesDiscovered(int transID, ServiceRecord[] servRecord) {
if(servRecord!=null && servRecord.length>0){
connectionURL=servRecord[0].getConnectionURL(0,false);
}
}
//implement this method since services are not being discovered
public void serviceSearchCompleted(int transID, int respCode) {
}
}
Not sure what the exact problem is, but you definitely don't want to be doing this in your midlet's startApp() method. This is a system lifecycle method, and should return quickly, but scanning for bluetooth devices will block it for a long time. Your startApp() method is tying up the device's resources which it could need for doing the actual scanning!
Refactor, so your device scanning is done in a new thread, then see what happens.
You seem to have misunderstood how the Bluetooth API works. The startInquiry method only starts the device discovery process and returns immediately afterwards, leaving the discovery running in the background. When devices are discovered, you get a callback of the deviceDiscovered method for each of them, and when the discovery process has completed, you get a callback of the inquiryCompleted method. So you need to move the accessing of the vecDevices member and the form manipulation from startApp to inquiryCompleted to be able to actually show the discovered information.
You say all devices are on - but also check if all devices are discoverable.
I've made this mistake before myself!
Lookup the method LocalDevice.setDiscoverable() if you want to toggle between modes programatically.