searchfiles.java

J2ME下开发的P2P搜索程序,功能较基础,较简单,可供学习和参考使用.

/**
 *   Importing the basic packages required by various classes during 
 *	 the execution of the program.	
 */ 
  import com.sun.kjava.*;
  import java.lang.*;
  import javax.microedition.io.*;
  import java.io.*;
  import java.util.*;

 /**
  *  The packages below are included because these packages are 
  *	 required by the XML classes.
  */
 import org.kxml.*;
 import org.kxml.io.*;
 import org.kxml.parser.*;
 
//  Declaration of a class searchfiles used for client level 
//	searching.
  public class searchfiles extends Spotlet 
  {
//  Declaring button variables.
  	private Button search;
  	private Button cancel;

// Declaring textField variables. 
     private TextField option;	
  
  	String parent_information;
  	String text_for_display;
/**
 *   Declaraing variables to folder_data where the folder information  
  *   is stored similerly the variable file_data where the file 
  *   information is stored.
  */  
  	String folder_data;
  	String file_data;
  	
  	int counter;
  
// Storing the parent address..
  	String host_address;
//  Declaring StreamConnection variable used for Sockets.. 
  	StreamConnection socket = null;
//  Declaring InputStreams and OutputStreams used by the socket 
//  connections.
  	InputStream socket_inputstream;
      OutputStream socket_outputstream;
  	Vector folder_vector;
/**
*   Declaraing variables for the xmlparser and parse event(Where 
*   the call backs after the parsing will be stored.	
*/  
  	AbstractXmlParser xmlparser;
  	ParseEvent event;
  
// searchfiles constructor	
  	searchfiles(String address, String parent_information)
  	{
// initializing the parameters with the varaiables declared 
	// earlier.
 			host_address = address;	
 			this.parent_information = parent_information;

// The current graphics is obtained...	
 			Graphics graphics = Graphics.getGraphics();	
/**
	 *  Initializing the variable of the graphics class and clearing   
	 *	the drawing region by calling the appropriate functions of 
	 *	the Graphics class namely (resetDrawRegion() and clearScreen()).
	 */  
  			graphics.resetDrawRegion();
  	        graphics.clearScreen();	
  		
	/**
	 *  Displaying a string (Title) at a specified position by using 
     *	the member function of the Graphics class
     */ 
  		    graphics.drawString("Search for Files / Folders",30,15);
	
	//	To make the spotlet as the current spotlet..

  			register(NO_EVENT_OPTIONS);	
 
	/**
	 *  Initializing the button object "search", placing it on the screen 
	 *	 at the appropriate position and then painting(drawing it).
	 */ 
  			search = new Button("Search",25,95);
  			search.paint();
  			
	/**
	 *  Initializing the button object "cancel", placing it on the screen 
	 *	at the appropriate position and then painting(drawing it).
	 */ 
  			cancel = new Button("Cancel",65,95);
  			cancel.paint();
  
 /**
  *  Initializing the TextFiled object option, placing it on the screen 
  *	 at the appropriate position ,painting(drawing it) and making the 
  *	 caret blink by setting the TextField as the current field.
  */  
 			option = new TextField("Search Criteria:",10,45,140,15);	
 			option.paint();
 			option.setUpperCase(true);
 			option.setFocus();
 	}	// End Constructor..
 
	// Event Handling function. (KeyDown)..
 	  public void keyDown(int x)
        {
	// Handle the input if the TextField is in focus.	
           if(option.hasFocus())
             {
               option.handleKeyDown(x);
             }
        }
 
	// Event Handling function. (penDown)..
 	   public void penDown(int x, int y)    
 	   {
	// If search button is pressed..
 		   if(search.pressed(x,y))
            {
 				folder_vector = new Vector();
	// The variables are assigned ..
 			   text_for_display = "";
 			   folder_data = "";
 			   file_data = "";
 			   counter = 1;
 				 try
 				  {
// A Socket connection is made on a port with the Listener(host address) 
 				  socket =  			  		       (StreamConnection)Connector.open("socket://"+host_address+":7070",Connector.READ_WRITE,true);	
 
	// If the socket is null then the connection is not established.
 					if (socket != null) 
 					{
 					System.out.println("Connection is established to localhost on port 7070...");
 					}
 							
 					
 					///  Opening the Input and Output Streams...				 
 					
 					socket_inputstream = socket.openInputStream();
 					socket_outputstream = socket.openOutputStream();
 				   }
 				   catch(IOException ae)
 				   {
 				   System.out.println("Couldn't open socket:");
 				   }
 		
	// An XMLRequest which is to be sent to the Listener is formed..
 					String xmlRequest = "<?xml version='1.0' encoding='utf-8'?> <p2p_lng><request type=\"SEARCH\"><scope type=\""+parent_information+option.getText()+"\" mask=''></scope></request></p2p_lng>";
 									
	// It is converted to byte array
	byte [] byteXmlRequest = xmlRequest.getBytes();
	// The length of the byte array is taken out.
 		int byteXmlRequest_length = byteXmlRequest.length;
 	
/**
 * 	A function appropriate length is called which will make
 *	this request equal to 1024 bytes in length this is done in
 *	order to make compatibilty with the C# listeners.
 */ 
   		byteXmlRequest = appropriatelength(byteXmlRequest,byteXmlRequest_length);
 
 				try
  				{
	// The xmlrequest is sent via socket connection to the Listener
	// machine..
  				socket_outputstream.write(byteXmlRequest);
	// The stream of response by the server is then passed on to 
	// the xmlparser for parsing..

    			    xmlparser = new XmlParser(new InputStreamReader(socket_inputstream));
  				}
  				catch(IOException e)
  				{
  				}
  		
		// Function used for parsing is called...
  				parseData();
  	// Remove the focus from the TextField and kill the TextField 
	// blinking caret
  				option.loseFocus();
  				option.killCaret();
	// To show a new class fist unregister all the controls of the 
	// existing class.
  				unregister();
	/// Class showfiles is called with the parameters..
  				new showfiles(text_for_display,folder_vector,host_address, "LOST",false);	
  		   }
	// If cancel is pressed...
  		   if(cancel.pressed(x,y))
             {
  			   folder_vector = new Vector();
  			   text_for_display = "";
  			   folder_data = "";
  			   file_data = "";
  			   counter = 1;
  				 try
  				  {
// A Socket connection is made on a port with the Listener 
  				  socket =  			  		       (StreamConnection)Connector.open("socket://"+host_address+":7070",Connector.READ_WRITE,true);	
  
	// If the socket is null then the connection is not established.
  					if (socket != null) 
  					{
  					System.out.println("Connection is established to localhost on port 7070...");
  					}
  							
  					///
  					///  Opening the Input and Output Streams...				 
  					
  							
  					socket_inputstream = socket.openInputStream();
  					socket_outputstream = socket.openOutputStream();
  				   }
  				   catch(IOException ae)
  				   {
  				   System.out.println("Couldn't open socket:");
  				   }
  			
	// An XMLReuest which is to be sent ot the Listener is formed..
  					String xmlRequest = "<?xml version='1.0' encoding='utf-8'?> <p2p_lng><request type=\"SEARCH\"><scope type=\""+parent_information+"*.*\" mask=''></scope></request></p2p_lng>";
		// It is converted to byte array

  											
  				byte [] byteXmlRequest = xmlRequest.getBytes();
	// The length of the byte array is taken out.
  				int byteXmlRequest_length = byteXmlRequest.length;
  
/**
 * 	A function appropriate length is called which will make
 *	this request equal to 1024 bytes in length this is done in
 *	order to make compatibilty with the C# listeners.
 */ 
    		byteXmlRequest = appropriatelength(byteXmlRequest,byteXmlRequest_length);
  
  		
  				try
  				{
		// The xmlrequest is sent via socket connection to the Listener
		// machine..
  				socket_outputstream.write(byteXmlRequest);
	// The stream of response by the server is then passed on to 
	// the xmlparser for parsing..

  				
    			    xmlparser = new XmlParser(new InputStreamReader(socket_inputstream));
  				}
  				catch(IOException e)
  				{
  				}
  			    
		// Function used for parsing is called...
  				parseData();
  		
		// Remove the focus from the TextField and kill the TextField 
		// blinking caret
  				option.loseFocus();
  				option.killCaret();
		// To show a new class fist unregister all the controls of the 
		// existing class.
  				unregister();
		/// Class showfiles is called with the parameters.
  new showfiles(text_for_display,folder_vector,host_address, "ROOT",false);	
  
  		   }
  	   }
 
// Function parseData (it will hold the callbacks generated by the 
// XMLParsing.
  		void parseData()
  		{
	// Move in loop till the XML document ends..
  		  do
  		   {
  		    try
  		     {	
  				event = xmlparser.read ();
  				if(event.getType()==Xml.START_TAG)
  				{
  					StartTag stag = (StartTag)event;
	// The Start Tag is identified
  					String name = stag.getName();
	/**
	 * If the Tag encountered is fileinfo then the Attributes of the   
	 * tag are taken using the function getValue(). and are added to 
	 * there appropriate position.	
	 */ 

  					if (name.equals("fileinfo"))
  					{
  
  	String filename = stag.getValue("filename");
  	
	// A check is made for the filename and folders and 
	// They are stored in seperate String varaiables.
  	 
  			if (!(filename.charAt(filename.length()-1)  == '\\'))
  			{
  			filename = filename.substring(filename.lastIndexOf('\\')+1);
  			file_data = file_data+filename+"\n";
  			}
  			else
  			{
  			
  			folder_data = folder_data + counter +".  "+filename+"\n";
	// The folders are also stored in a vector variable of the
	// name folder_vector.
  			folder_vector.addElement((Object)filename);
  			counter++;
  			}
  
  				}
  					
  				}
  							
  
  		   }
  		   catch(IOException ex)
  		   {		
  				System.out.println("Exception occured");
  		   }
  		}
  		while (!(event instanceof EndDocument));
  		
  		System.out.println("**** END OF DOCUMENT ****");
		// end of document
		// Socket Connection and Input and OutputStreams are  
		// closed...
  		try
  		{
  		socket.close();
  		socket_inputstream.close();
  		socket_outputstream.close();
  		}
  		catch(IOException e)
  		{
  			System.out.println(e);
  			
  		}
	// Numbering is done on the file name stored in the String
	// variable by the name file_data.
  		if (!file_data.equals(""))
  		{
  		 file_data = counter+".  "+file_data;
  		 counter++;
  		}
  		 StringBuffer file_data_buffer = new StringBuffer();
  
  		for (int i = 0;i<file_data.length()-1 ;i++ )
  		{
  			if (file_data.charAt(i) == '\n')
  			{
  				file_data_buffer = file_data_buffer.append(file_data.charAt(i));
  				file_data_buffer = file_data_buffer.append(counter+".  ");
  				counter++;
  			}
  			else
  			{
  				file_data_buffer = file_data_buffer.append(file_data.charAt(i));
  			}
  			
  		}		
  		file_data = file_data_buffer.toString();
	//  the Final text to be displayed in the displayed in the 
	//  varaiable textFor Display..
  
  		text_for_display = "       Folders    \n"+folder_data+"\n"+"       Files      \n"+file_data;
  
  	 }
	// This function is called to make the program compatible with 
	// the C# Listeners.
  	 	public byte [] appropriatelength(byte[] file_bytes, int file_size)
  		{
  				int count = 0;
  				byte b[] = new byte[1024];
  				int remaining = 1024-file_size;
  
  				for (int i = 0;i<file_bytes.length ;i++ )
  				{
  					b[i] = file_bytes[i];
  				}
  				
  				char a[] = new char[remaining];
  		
  				for (int i = 0;i<remaining ;i++ )
  				{
  				a[i] = 13;
  				}
  
  				String tempw = new String(a);
  				byte d[] = tempw.getBytes();
  
  				for (int i=file_size;i<1024 ;i++ )
  				{
  				b[i] = d[(i-file_size)];
  				}
  				
  				return (b);
  		}			// End Appropriate length.....
  
  }		// End of the class searchfiles...