Tutorial
Prerequisites
- Download Eclipse Classic
Creating and Setting the Interface Bundle
- Run Eclipse
- Select/Enter your preferred workspace in the text box provided and click okay
- After Eclipse has completed loaded, create a plug-in by clicking on "File" on the menu bar then scroll to New->Project->Plug-in
- Enter the following information that is seen in the image below
- Click Next->Finish
- Now open the src folder, open the package inside, remove the activator file currently residing in it, and create a class called "Weather" and an interface called "WeatherSystem"
- Copy and paste the following code to their respective file
Weather
package ecl.team2.lab2.weather;
public class Weather {
private String city;
private float tempInCelcius;
private float rainInMM;
private float snowInMM;
private float windspeedInKM;
private char windDirection;
public Weather(String pcity, float ptemp, float prain, float psnow, float pwspeed, char pwdirection){
this.setCity(pcity);
this.setTempInCelcius(ptemp);
this.setRainInMM(prain);
this.setSnowInMM(psnow);
this.setWindspeedInKM(pwspeed);
this.setWindDirection(pwdirection);
}
public void setWindDirection(char windDirection) {
this.windDirection = windDirection;
}
public char getWindDirection() {
return windDirection;
}
public void setWindspeedInKM(float windspeedInKM) {
this.windspeedInKM = windspeedInKM;
}
public float getWindspeedInKM() {
return windspeedInKM;
}
public void setSnowInMM(float snowInMM) {
this.snowInMM = snowInMM;
}
public float getSnowInMM() {
return snowInMM;
}
public void setRainInMM(float rainInMM) {
this.rainInMM = rainInMM;
}
public float getRainInMM() {
return rainInMM;
}
public void setTempInCelcius(float tempInCelcius) {
this.tempInCelcius = tempInCelcius;
}
public float getTempInCelcius() {
return tempInCelcius;
}
public void setCity(String city) {
this.city = city;
}
public String getCity() {
return city;
}
}
WeatherSystem
package ecl.team2.lab2.weather;
public interface WeatherSystem {
Weather getWeather(String city) throws Exception;
}
- Save and close both files and now open the manifest file
- Click on the runtime tab then click on add in the "export packages" panel.
- click on the ecl.... package and click okay
- Now close the manifest and save all changes
Creating and Setting the Provide Bundle
- Follow the same steps for creating a new plug-in projects but instead supply the name "ecl.team2.lab2.weathersystem.provider"
- Remove all contents within the src->current package and add a class file called "ProviderActivator"
- Add a new package to the current project we're dealing with and name it "ecl.team2.lab2.weathersystem.provider.internal" and within it create a class called "SimpleWeatherSystem"
- Copy and paste the following code to their respective file
ProviderActivator
package ecl.team2.lab2.weathersystem.provider;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import ecl.team2.lab2.weather.WeatherSystem;
import ecl.team2.lab2.weathersystem.provider.internal.SimpleWeatherSystem;
public class ProviderActivator implements BundleActivator {
private static BundleContext context;
static BundleContext getContext() {
return context;
}
/*
* (non-Javadoc)
* @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext)
*/
public void start(BundleContext bundleContext) throws Exception {
ProviderActivator.context = bundleContext;
SimpleWeatherSystem sws = new SimpleWeatherSystem();
context.registerService(WeatherSystem.class.getName(), sws, null);
System.out.println("Weather Station On !");
}
/*
* (non-Javadoc)
* @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext)
*/
public void stop(BundleContext bundleContext) throws Exception {
ProviderActivator.context = null;
System.out.println("Weather Station Off !");
}
}
SimpleWeatherSystem
package ecl.team2.lab2.weathersystem.provider.internal;
import ecl.team2.lab2.weather.WeatherSystem;
import ecl.team2.lab2.weather.Weather;
import java.util.ArrayList;
import java.util.Random;
public class SimpleWeatherSystem implements WeatherSystem {
ArrayList<Weather> weathers = new ArrayList<Weather>();
public SimpleWeatherSystem(){
ArrayList<String> cities = new ArrayList<String>();
cities.add("Toronto");
cities.add("New York");
cities.add("Calgary");
cities.add("Ottawa");
cities.add("Vancouver");
cities.add("Regina");
cities.add("Winnipeg");
cities.add("St. John");
cities.add("Fredericton");
cities.add("Halifax");
cities.add("Quebec City");
cities.add("Whitehorse");
cities.add("Yellowknife");
for(String c:cities){
Random randomGenerator = new Random();
float temp = randomGenerator.nextFloat()+35;
float rain = randomGenerator.nextFloat()+10;
float snow = randomGenerator.nextFloat()+10;
float windspeed = randomGenerator.nextFloat()+50;
char winddirection = '.';
int r = randomGenerator.nextInt(4);
switch(r){
case 0:
winddirection = 'E';
break;
case 1:
winddirection = 'W';
break;
case 2:
winddirection = 'N';
break;
case 3:
winddirection = 'S';
break;
}
Weather w = new Weather(c, temp, rain, snow, windspeed, winddirection);
this.weathers.add(w);
System.out.println(w.toString());
}
}
public Weather getWeather(String city) throws Exception {
// TODO Auto-generated method stub
Weather found = null;
for(Weather w:this.weathers){
city = city.toLowerCase();
String wcity =w.getCity().toLowerCase();
if(city.equals(wcity)){
found = w;
return found;
}
}
return found;
}
}
- Save and close both files and now open the manifest file
- Click on the dependencies tab then click on add in the "import packages" panel.
- In the search field, enter "ecl", then click on "ecl.team2.lab2.weather", and afterwords click okay
Creating and Implementing the Client Bundle
- Follow the same steps for creating a new plug-in projects but instead supply the name "ecl.team2.lab2.weathersystem.client"
- Remove all contents within the src->current package and add a class file called "Activator" and another class file called "
- Copy and paste the following code to their respective file
Activator
package ecl.team2.lab2.weathersystem.client;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import ecl.team2.lab2.weather.WeatherSystem;
public class Activator implements BundleActivator {
private static BundleContext context;
private WeatherSystem sws;
static BundleContext getContext() {
return context;
}
/*
* (non-Javadoc)
* @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext)
*/
public void start(BundleContext bundleContext) throws Exception {
Activator.context = bundleContext;
ServiceReference reference = context.getServiceReference(WeatherSystem.class.getName());
if(reference != null){
sws = (WeatherSystem) context.getService(reference);
if(sws != null) {
WeatherDialog.runDialog(sws);
context.ungetService(reference);
} else
System.err.println("The Weather Station is down !!!");
} else
System.err.println("The Weather Station can not be found !!!");
}
/*
* (non-Javadoc)
* @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext)
*/
public void stop(BundleContext bundleContext) throws Exception {
Activator.context = null;
System.err.println("Client Not Interested !");
}
}
WeatherDialog
package ecl.team2.lab2.weathersystem.client;
import javax.swing.*;
import ecl.team2.lab2.weather.WeatherSystem;
import java.awt.*;
import java.awt.event.*;
public class WeatherDialog extends JFrame{
private static final long serialVersionUID = 1L;
private JPanel panel;
private JButton btnGo;
private JComboBox combo;
private JLabel labelTitle;
private JLabel labelTemperature;
private JLabel labelRain;
private JLabel labelSnow;
private JLabel labelWindDirection;
private JLabel labelWindSpeed;
private WeatherSystem sws;
String[] cities = {"Toronto","New York","Calgary","Ottawa","Vancouver",
"Regina","Winnipeg","St. John","Fredericton",
"Halifax","Quebec City", "Whitehorse","Yellowknife"
};
public WeatherDialog(){
panel = new JPanel();
panel.setPreferredSize(new Dimension(200,200));
panel.setLayout(new FlowLayout(FlowLayout.LEFT));
combo = new JComboBox();
for(int i=0;i<cities.length;i++){
combo.addItem(cities[i]);
}
panel.add(combo);
btnGo = new JButton("Go");
panel.add(btnGo);
btnGo.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
String chosencity = (String)combo.getSelectedItem();
ShowWeather(chosencity);
}
}
);
this.labelTitle = new JLabel();
this.labelTemperature = new JLabel();
this.labelRain = new JLabel();
this.labelSnow = new JLabel();
this.labelWindDirection = new JLabel();
this.labelWindSpeed = new JLabel();
panel.add(labelTitle);panel.add(labelTemperature);panel.add(labelRain);
panel.add(labelSnow);panel.add(labelWindDirection);panel.add(labelWindSpeed);
this.setTitle("Todays Weather");
// Display the window.
this.setContentPane(panel);
this.pack();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.setLocationRelativeTo(null);
}
public void ShowWeather(String city){
try {
float temp = sws.getWeather(city).getTempInCelcius();
float rain =sws.getWeather(city).getRainInMM();
float snow = sws.getWeather(city).getSnowInMM();
char direction = sws.getWeather(city).getWindDirection();
float speed = sws.getWeather(city).getWindspeedInKM();
this.labelTitle.setText("Todays weather in "+ city);
this.labelTemperature.setText("Temperature: "+ String.format("%.2f", temp) + " Celcius");
this.labelRain.setText("Rain: " + String.format("%.2f", rain) + " mm");
this.labelSnow.setText("Snow: " + String.format("%.2f", snow) + " mm");
this.labelWindDirection.setText("Wind Direction: " + direction);
this.labelWindSpeed.setText("Speed: " + String.format("%.2f", speed) + " km/hr");
}
catch (Exception ex){
System.err.println(ex.getMessage());
}
}
private static void createAndShowGUI(WeatherSystem ws) {
WeatherDialog frame = new WeatherDialog();
frame.sws = ws;
}
public static void runDialog(final WeatherSystem ws) {
// Schedule a job for the event-dispatching thread:
// creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI(ws);
}
});
}
}
- Save and close all files