localcatalogmanager.java

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package local_catalog_manager;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.net.URL;
import java.net.URLConnection;

import org.apache.xerces.dom.DocumentImpl;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import java.net.MalformedURLException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.StringTokenizer;
import java.nio.ByteBuffer;
import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;
import static java.nio.channels.FileChannel.MapMode.READ_ONLY;



public class LocalCatalogManager {
	private LocalCatalogEntry[] info;
	private File lcmf;
	private Document doc;
	
	public boolean isEmpty()
	{
		boolean e=false;
		if((info==null)||(info[0].getTitle()==null))
			e=true;
		return e;
	}
	
	/**
	 * @return the doc
	 */
	public Document getDoc() {
		return doc;
	}

	public LocalCatalogManager()
		{
			
			lcmf=new File("lmcf.xml");
			
			if(!lcmf.exists())
				{
					doc=new DocumentImpl();
					Element root=doc.createElement("lcm");
					doc.appendChild(root);
					try{System.out.println("saving");
				 	  Transformer transformer= TransformerFactory.newInstance().newTransformer();
				 	  //String systemID=doc.getDoctype().getSystemId();
				 	  //transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM,"prodotti.dtd");
				 	  transformer.setOutputProperty(OutputKeys.METHOD,"xml");
				 	  transformer.setOutputProperty(OutputKeys.INDENT,"yes");
				 	  DOMSource source=new DOMSource(doc);
				 	  FileOutputStream fos=new FileOutputStream(lcmf);
				 	  StreamResult result = new StreamResult (fos);
				 	  transformer.transform(source,result);
				  	}
					catch(TransformerConfigurationException tce){System.out.println("tce");}
					catch(TransformerException te){System.out.println("te");}
					catch(IOException ioe){System.out.println("ioe");}}
				
			else
				{
					DocumentBuilder db = null;
					DocumentBuilderFactory dbf =DocumentBuilderFactory.newInstance();
					try {
						db = dbf.newDocumentBuilder();
					} catch (ParserConfigurationException pce) {pce.printStackTrace();}
					try{doc=db.parse(lcmf);}
					catch(IOException ioe){}
					catch(SAXException saxe){}
					NodeList nl=doc.getElementsByTagName("entry");
					if (nl.getLength()>0)
						{
							info=new LocalCatalogEntry[nl.getLength()];
							for(int i=0;i<nl.getLength();i++)
							{
								NodeList nl2=nl.item(i).getChildNodes();
								String t=null;
								String d=null;
								String h=null;
								URL u=null;
								for(int j=0;j<nl2.getLength();j++)
									{
										Node n=nl2.item(j);
										if(n.getNodeName().equals("title"))
											{
												NodeList tx=n.getChildNodes();
												t=tx.item(0).getNodeValue();
											}
										if(n.getNodeName().equals("description"))
											{
												NodeList tx=n.getChildNodes();
												d=tx.item(0).getNodeValue();
											}
										if(n.getNodeName().equals("url"))
											{
												NodeList tx=n.getChildNodes();
												try{u=new URL(tx.item(0).getNodeValue());}
												catch (MalformedURLException mue){}
											}
										if(n.getNodeName().equals("hash"))
										{
											NodeList tx=n.getChildNodes();
											h=tx.item(0).getNodeValue();
										}
										
									}
								info[i]=new LocalCatalogEntry(t,d,u,h);
							}
						}
				}
			digestFiles();
		
		}
	
	public void digestFile(LocalCatalogEntry lce,boolean dw)
		{
			if(lce.getHash()==null){
			String f=null;
			OutputStream out = null;
			URLConnection conn = null;
			InputStream  in = null;
			MessageDigest md=null;
			try{URL u=lce.getUrl();
			u.openStream();
			String fn=u.getFile();
 	 		StringTokenizer st=new StringTokenizer(fn,"/");
 	 		while(st.hasMoreTokens())
				 f=st.nextToken(); 		
			
			out = new BufferedOutputStream(
				new FileOutputStream(f));
			conn = u.openConnection();
			in = conn.getInputStream();
			byte[] buf = new byte[1024];
			int numRead;
			long numWritten = 0;
			while ((numRead = in.read(buf)) != -1) {
				out.write(buf, 0, numRead);
				numWritten += numRead;
			}
		}catch (Exception e){}
		finally {
			try {
				if (in != null) {
					in.close();
				}
				if (out != null) {
					out.close();
				}
				} catch (IOException ioe) {}
				}
				try{
					FileChannel channel = new RandomAccessFile(f, "r").getChannel();
					ByteBuffer buffer = channel.map(READ_ONLY, 0, (int)channel.size());
					try {md = MessageDigest.getInstance("SHA");}
					catch (NoSuchAlgorithmException nsa){}
					md.update(buffer.duplicate());
					byte[] digest = md.digest();
					channel.close();
					String d=null;
					d=this.byteArrayToHexString(digest);
					lce.setHash(d);		
					
				}	
			catch(Exception e){e.printStackTrace();}
			if(!dw)
			{
				File de=new File(f);
				de.delete();
			}
			}
		}
	
	
	public void digestFiles()
		{
			NodeList nl=doc.getElementsByTagName("url");
			
			String f=null;
			for (int i=0;i<nl.getLength();i++)
			{
				Node root=nl.item(i).getParentNode();
				Element r =(Element) root;
				if(r.getElementsByTagName("hash")==null){
				NodeList nl2=nl.item(i).getChildNodes();
				Node n=nl2.item(0);
				OutputStream out = null;
				URLConnection conn = null;
				InputStream  in = null;
				MessageDigest md=null;
			try{
				URL u=new URL(n.getNodeValue());
				u.openStream();
				String fn=u.getFile();
	 	 		f=fn.substring(1);
				out = new BufferedOutputStream(
					new FileOutputStream(f));
				conn = u.openConnection();
				in = conn.getInputStream();
				byte[] buf = new byte[1024];
				int numRead;
				long numWritten = 0;
				while ((numRead = in.read(buf)) != -1) {
					out.write(buf, 0, numRead);
					numWritten += numRead;
				}
			}catch (Exception e){}
			finally {
				try {
					if (in != null) {
						in.close();
					}
					if (out != null) {
						out.close();
					}
					} catch (IOException ioe) {}
				}
			try{
				FileChannel channel = new RandomAccessFile(f, "r").getChannel();
				ByteBuffer buffer = channel.map(READ_ONLY, 0, (int)channel.size());
				try {md = MessageDigest.getInstance("SHA");}
				catch (NoSuchAlgorithmException nsa){}
				md.update(buffer.duplicate());
				byte[] digest = md.digest();
				channel.close();
				String d=null;
				d=this.byteArrayToHexString(digest);
				System.out.println(d);									
			}	
		catch(Exception e){e.printStackTrace();}
			
			}
			
			}
			
		}
	
	static byte[] hexStringToByteArray(String in)
		{
			byte [] ba= new byte[in.length()/2];  
			    for(int i=0; i<(in.length()/2); i++){
			    	byte firstNibble  = Byte.parseByte(in.substring(2*i,2*i+1),16); // [x,y)
			    	byte secondNibble = Byte.parseByte(in.substring(2*i+1,2*i+2),16);
			    	int finalByte = (secondNibble) | (firstNibble << 4 ); // bit-operations only with numbers, not bytes.
			    	ba[i] = (byte) finalByte;
			    }  
			

			return ba;
		}
	
	static String byteArrayToHexString(byte in[]) {

	    byte ch = 0x00;

	    int i = 0; 

	    if (in == null || in.length <= 0)

	        return null;

	        

	    String pseudo[] = {"0", "1", "2",
	"3", "4", "5", "6", "7", "8",
	"9", "a", "b", "c", "d", "e",
	"f"};

	    StringBuffer out = new StringBuffer(in.length * 2);

	    

	    while (i < in.length) {

	        ch = (byte) (in[i] & 0xF0); // Strip off high nibble

	        ch = (byte) (ch >>> 4);
	     // shift the bits down

	        ch = (byte) (ch & 0x0F);    
//	 must do this is high order bit is on!

	        out.append(pseudo[ (int) ch]); // convert the	nibble to a String Character

	        ch = (byte) (in[i] & 0x0F); // Strip off	low nibble 

	        out.append(pseudo[ (int) ch]); // convert the	nibble to a String Character

	        i++;

	    }

	    String rslt = new String(out);

	    return rslt;

	}    
	
	private boolean searchURL(URL u)
	{
		boolean r=false;
		int i=0;
		if (info==null)
		{return false;}
		while((!r)&&(i<info.length))
		{
			if(info[i].getUrl().equals(u))
				{r=true;System.out.println("trovato");}
			i++;
		}
		return r;		
	}
	
	public void insert(String t,String d,URL u, boolean dw)
		{
			if(!searchURL(u)){
			LocalCatalogEntry [] temp;
			if(info!=null) 
				{
					temp=new LocalCatalogEntry[info.length+1];
			
					for(int i=0;i<info.length;i++)
							temp[i]=info[i];
					temp[temp.length-1]=new LocalCatalogEntry(t,d,u);
					info=temp;
				}
			else
			{
				temp=new LocalCatalogEntry[1];
				temp[0]=new LocalCatalogEntry(t,d,u);
				info=temp;
			}
			digestFile(info[temp.length-1],dw);
			Element root=doc.createElement("entry");
			NodeList n=doc.getElementsByTagName("lcm");
			Node r=n.item(0);
			r.appendChild(root);
			Node titleE=doc.createElement("title");
			Node titleT=doc.createTextNode(t);
			titleE.appendChild(titleT);
			root.appendChild(titleE);
			Node descE=doc.createElement("description");
			Node descT=doc.createTextNode(d);
			descE.appendChild(descT);
			root.appendChild(descE);
			Node urlE=doc.createElement("url");
			Node urlT=doc.createTextNode(u.toString());
			urlE.appendChild(urlT);
			root.appendChild(urlE);
			Node hashE=doc.createElement("hash");
			Node hashT=doc.createTextNode(info[temp.length-1].getHash());
			hashE.appendChild(hashT);
			root.appendChild(hashE);
			try{
			Transformer transformer= TransformerFactory.newInstance().newTransformer();
		 	  //String systemID=doc.getDoctype().getSystemId();
		 	  //transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM,"prodotti.dtd");
		 	  transformer.setOutputProperty(OutputKeys.METHOD,"xml");
		 	  transformer.setOutputProperty(OutputKeys.INDENT,"yes");
		 	  DOMSource source=new DOMSource(doc);
		 	  FileOutputStream fos=new FileOutputStream(lcmf);
		 	  StreamResult result = new StreamResult (fos);
		 	  transformer.transform(source,result);
		  	}
		 	catch(TransformerConfigurationException tce){System.out.println("tce");}
			catch(TransformerException te){System.out.println("te");}
			catch(IOException ioe){System.out.println("ioe");}
			}
		}
	
	/**
	 * @return the info
	 */
	public LocalCatalogEntry[] getInfo() {
		return info;
	}
	

}