weather.java

Mobile Services

/* 	Importing the basic packages required by various classes 
 	during execution of the program    */
import java.util.Hashtable;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.rms.*;
import javax.microedition.io.*;
import java.util.*;
import java.io.*; 
import java.lang.*;
 
 
 /* Declaration of the class Weather. */
 public class Weather extends MIDlet implements CommandListener
 {
	/* Declare an object for GetData class */
	DataParser getd;
 	
 	/* Declaring  variable for requesting that object to be displayed on the device */
 	private Display displaylist;
 
 	/* Declaring List type variables for storing and displaying list of cities and details of weather  */
 	private List states, details;
 
 	/* Declare and create vector type variables for storing list of cities and	list of labels  */
 	private Vector vstate = new Vector();
  	private Vector vlist = new Vector();
  		
  	/* Declaring variables for Command Buttons and initializing with null */
  	private Command cancelcommand = null;
 	private Command okcommand = null;
 	private Command goback = null;
 	private Command exit = null;
 
 	/*	Declaring Hashtable object and initialising it with null  */
 	private Hashtable htable = null;
  	
 	/* Creating  object of RecordStore type and initialising it with null */
 	RecordStore recordstore = null;	
 	
 	/* Declaring object of Class MainClass */
 	private MainClass lastscreen;
 	
 	/* Declaring constructor of Class Weather */
 	public Weather(Display displayweather, MainClass obj)
 	{
 		/* initializing Mainclass object lastscreen with the argument obj */
 		lastscreen = obj;
 		
 		/* Getting the current reference of any object which is present at run time 
	   for displaying it on the cellpone screen */
 		displaylist = displayweather;
 
         /* Create an object of List type to store the list of Cities */
 		states = new List("States",List.IMPLICIT);
 				
 		/* Registering the List object states for event Handling */
 		states.setCommandListener(this);
 
 		/* Creates an object for hashtable htable */
 		htable = new Hashtable();
 		
 		/* Creates an object for exit command defined as screen and give the  priority 2  */
 		exit = new Command("Exit",Command.EXIT,2);
 
 		/* Creates an object for Back  command defined as Command and given the priority 2 */
 		goback = new Command("Back",Command.BACK,1);
 		
 		/* Creates an object for Ok command defined as screen and given the priority 1 */
 		okcommand = new Command("OK",Command.SCREEN,1);
 
 		/* Creates an object for Cancel command defined as Screen and given the priority 2 */
 		cancelcommand = new Command("Cancel",Command.SCREEN,2);
  
 		/* Inserts label into vector vlist */
 		vlist.insertElementAt("State",0);
 		vlist.insertElementAt("Date",1);
  		vlist.insertElementAt("Sunrise",2);
 		vlist.insertElementAt("Sunset",3);
  		vlist.insertElementAt("Moonrise",4);
  		vlist.insertElementAt("Moonset",5);
  		vlist.insertElementAt("Day Humidity",6);
  		vlist.insertElementAt("Night Humidity",7);
 		vlist.insertElementAt("Day Wind Direction",8);
 		vlist.insertElementAt("Night Wind Direction",9);
  		vlist.insertElementAt("Day Wind Speed",10);
 		vlist.insertElementAt("Night Wind Speed",11);
 		vlist.insertElementAt("High Temp",12);
 		vlist.insertElementAt("Low Temp",13);
  		vlist.insertElementAt("Rain Fall",14);
 		vlist.insertElementAt("Forecast",15);
 	}
  	/* Declarartion of the method startApp */
  	/* Application Starts from this method */
  	public void startApp()
  	{
  
  		/* Store the path of xml file in url object as string */
  		String url = new String("http://192.192.168.100/midlet/template/midlet_weather.xml");
 		
  		/* Creating an object for DataParser class */
  		getd = new DataParser();
  				
  		/* Calling the method sourceurl and sending the path of the xml file */
  		getd.sourceurl(url);
  		
  		/* Calling  the read_record method for parsing XML file and
  		 storing the records into the Database and Hashtable */ 
  		getd.read_record();
  		
  		/*  Calling  the returnState method and returning the records in hashtable */
  		htable = getd.returnState();
 				
 		/*  Creates an object that implements the Enumeration interface generating a series of elements  
  			and the loop will execute till any element is present in Enumeration e object */ 
			for (Enumeration e = htable.keys(); e.hasMoreElements() ;) 
 			{
  				/* Adding values to List Object states, present in the hashtable */
  				states.append( (String)e.nextElement() , null);
  			}
  		/* display List states on cellphone screen */
  		displaylist.setCurrent(states);
  		
  		/* To attach the ok command button with List states */ 
  		states.addCommand(okcommand);
  
  		/* To attach the cancel command button with List states */ 
  		states.addCommand(cancelcommand);
 	}
  	
  	/* Declaring method for eventhandling routines */
  	public void commandAction(Command c, Displayable d)
  	{
  	
  		/* if condition is associated with ok command button when the user clicks it  */
  		if(c == okcommand)
 		{
  			String st = "";
 			/* get the postion which is selected by the user in the List states  */
  			int index  = states.getSelectedIndex();
  			
  			/* Retrieving the hashtable value according to the index number */
  			String hash_id = (String)htable.get(states.getString(index));
  			
  			/* Create an object details of List type to display the Weather Details */
  			details = new List("Weather of " +  states.getString(index)	, List.IMPLICIT) ;
  			
  			/* Registering the List object details for event Handling */
  			details.setCommandListener(this);
  			
  			/* displays List details on cellphone screen */
  			displaylist.setCurrent(details);
  					
  			try 
  			{
  				/* Opens the Recordstore addresses for retrieving the records */
  				recordstore = RecordStore.openRecordStore("addresses", true);	
  
  				/* Retreiving the record from the recordstore and storing it as String */
  				st = new String(recordstore.getRecord(Integer.parseInt(hash_id)));
  				
  				/* Closes the Recordstore after retrieving the records */
  				recordstore.closeRecordStore();	
  
  			}
  			catch(RecordStoreException rse) 
  			{
  				rse.printStackTrace();
  			}
  			
  			/* Declaring integer variables  */
  			int st_index = 0, end_index = 0, ctr = 0, pos ;
  			/* Storing the string length retrieved from the database */
  			int len = st.length();
  			
  			/* Declaring String type variable for storing the substring */ 
  			String sub_st = "";
 			
  			/* Declaring the character type array, creating space for array and 
  			   defining the size equivalent to string length */
  			char[] c_arr = new char[len];
  
  			/* Inserting String into character type array. */
  			c_arr = st.toCharArray();
  
  			/* For Loop for retreiving Weather record from the string and displaying it 
  			   on the cellphone screen */		
  			for (pos = 0; pos < len ; pos++)
  			{
  				if(c_arr[pos] == '?')
  				{
  					st_index = end_index ;
  					end_index = pos ;
  					ctr = ctr + 1;
  					if (ctr > 1)
  					{
  						sub_st = st.substring(st_index + 1,end_index);
  						details.append((String)vlist.elementAt(ctr - 2) + " " + sub_st, null);
 					}
  				}
  			}
  			/*  To attach the goback and exit command button with List details */
  			details.addCommand(goback);
  			details.addCommand(exit);
  		}
  
  		/* if condition is associated with exit command button when the user clicks it */
  		if(c == exit)
  		{
  			/* Destroys the weather application */
  			destroyApp( true );
 			/* Confirms application destroyed */ 
  			notifyDestroyed();
  			
  			/* The getDisplayObject method takes displayobject as parameter and displays the first screen of the application  */
  			lastscreen.getDisplayObject(displaylist); 
  		}
  		/* if condition is associated with cancel command button when the user clicks  */
  		if(c == cancelcommand)
  		{
  			/* Destroys the weather application */
  			destroyApp(true);
  			/* Confirms application destroyed */
  			notifyDestroyed();
  			
  			/* The getDisplayObject method takes displayobject as parameter and displays the first screen ot the application  */
  			lastscreen.getDisplayObject(displaylist);
  		}
  		/* if condition is associated with goback command button when the user clicks  */
  		if(c == goback)
  		{
  			/* displays List states on cellphone screen */
  			displaylist.setCurrent(states);
  			
  			/*  To attach the ok and cancel command button with List states */
  			states.addCommand(okcommand);
  			states.addCommand(cancelcommand);
  		}
  	}  
  		
  	/* Method called when the application is destroyed	*/
  	public void destroyApp(boolean b)
  	{
  		/* Deletes the records from the database by calling the deleterecords method  */
  		getd.deleterecords();
  	}
  	/* This method is called when the midlet is paused */
  	public void pauseApp()
  	{}		
}