Cv

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ExecutorService Sample

For Thread Management one can use simple Executor Service. We had lots of small job but time consuming jobs which
could execute later. Below is the sample code.

If you want the jobs to be executed in the order you give , use sequential.
Example : You want to fire a register event and then an email notification.
You want these to be executed in the order you submitted to queue.

If you are not interested in the order just use pooled.

protected static ThreadLocal<reentrantlock> requestLock = new ThreadLocal<reentrantlock>( ) ;  
   protected static ThreadLocal<condition> requestCondition = new ThreadLocal<condition>( ) ;  
   public static ReentrantLock getLock( boolean isInit )  
   {  
     ReentrantLock lock = requestLock.get( ) ;  
     if( lock == null &amp;&amp; isInit )  
     {  
       lock = new ReentrantLock( true ) ;  
       requestLock.set( lock ) ;  
     }  
     return lock ;  
   }  
   public static Condition getCondition( boolean isInit )  
   {  
     Condition con = requestCondition.get( ) ;  
     if( con == null &amp;&amp; isInit )  
     {  
       con = getLock( true ).newCondition( ) ;  
       requestCondition.set( con ) ;  
     }  
     return con ;  
   }  
 protected static ExecutorService _sequentialExecutor = null ;  
   protected static ExecutorService _pooledExecutor = null ;  
   static  
   {  
     init( true ) ;  
   }  
   public static void init( boolean isForce )  
   {  
     if( _sequentialExecutor != null &amp;&amp; _pooledExecutor != null &amp;&amp; !isForce )  
     {  
       return ;  
     }  
     _sequentialExecutor = Executors.newSingleThreadExecutor( ) ;  
     _pooledExecutor = Executors.newFixedThreadPool( 4 ) ;  
   }  
   public static <t> Future<t> sequentialExec( YTask<t> task, boolean isWaitForRequest )  
   {  
     if( isWaitForRequest )  
     {  
       ReentrantLock lock = getLock( true ) ;  
       // initialize the condition as well  
       getCondition( true ) ;  
       task.setLock( lock ) ;  
       if( !lock.isHeldByCurrentThread( ) )  
       {  
         lock.lock( ) ;  
       }  
     }  
     return _sequentialExecutor.submit( ( Callable )task ) ;  
   }  
   public static <t> Future<t> sequentialExec( YScheduledTask task )  
   {  
     return _sequentialExecutor.submit( ( Callable )task ) ;  
   }  
   public static <t> Future<t> sequentialExec( Callable<t> callable )  
   {  
     return _sequentialExecutor.submit( callable ) ;  
   }  
   public static <t> Future<t> pooledExec( YTask<t> task, boolean isWaitForRequest )  
   {  
     if( isWaitForRequest )  
     {  
       ReentrantLock lock = getLock( true ) ;  
       // initialize the condition as well  
       getCondition( true ) ;  
       task.setLock( lock ) ;  
       if( !lock.isHeldByCurrentThread( ) )  
       {  
         lock.lock( ) ;  
       }  
     }  
     return _pooledExecutor.submit( ( Callable )task ) ;  
   }  

YTask is a utility class for callable services via this class.

import java.util.concurrent.Callable ;  
 import java.util.concurrent.TimeUnit ;  
 import java.util.concurrent.locks.Condition ;  
 import java.util.concurrent.locks.ReentrantLock ;  
 public class YTask<t> implements Callable<t>, Runnable  
 {  
   protected Callable<t> callable ;  
   protected long delayMs = 0 ;  
   protected ReentrantLock lock = null ;  
   protected Condition condition = null ;  
   public YTask( Callable<t> callable )  
   {  
     this.callable = callable ;  
   }  
   public Callable<t> getCallable( )  
   {  
     return this.callable ;  
   }  
   public long getDelayMs( )  
   {  
     return this.delayMs ;  
   }  
   public ReentrantLock getLock( )  
   {  
     return this.lock ;  
   }  
   public void setLock( ReentrantLock lock )  
   {  
     this.lock = lock ;  
   }  
   public Condition getCondition( )  
   {  
     return this.condition ;  
   }  
   public void setCondition( Condition condition )  
   {  
     this.condition = condition ;  
   }  
   @Override  
   public void run( )  
   {  
     try  
     {  
       call( ) ;  
     }  
     catch( Exception e )  
     {  
       e.printStackTrace( ) ;  
       throw new RuntimeException( "Error during task...", e ) ;  
     }  
   }  
   @Override  
   public T call( ) throws Exception  
   {  
     T res = null ;  
     if( this.delayMs > 0 )  
     {  
       try  
       {  
         Thread.sleep( this.delayMs ) ;  
       }  
       catch( Exception e )  
       {  
         e.printStackTrace( ) ;  
       }  
     }  
     if( this.lock != null )  
     {  
       if( !this.lock.isHeldByCurrentThread( ) )  
       {  
         this.lock.lock( ) ;  
       }  
       System.err.println( "LOCK Info ytask : isHeldByCurrentThread() : " + this.lock.isHeldByCurrentThread( ) + ", getHoldCount() : " + this.lock.getHoldCount( ) + " , " + this.lock.getQueueLength( ) ) ;  
     }  
     try  
     {  
       if( this.callable != null )  
       {  
         if( this.condition != null )  
         {  
           if( !this.condition.await( 180, TimeUnit.SECONDS ) )  
           {  
             sendErrorMessage( null, "Error during waiting for lock in YTask", "Error during waiting for lock in YTask" ) ;  
           }  
         }  
         res = this.callable.call( ) ;  
       }  
       return res ;  
     }  
     finally  
     {  
       if( this.lock != null )  
       {  
         this.lock.unlock( ) ;  
       }  
     }  
   }  
 }  

Running a local http server for dumping output to webpage

Running a local http server for dumping output to webpage.

At our project for encryption ,we had the constraint that we will not be
putting descrypted or open data to network.
There is a client program (Swing) running encrypt decrypt jobs.
Encrypted files are stored at server.

Also users will be able to download encrypted files into their local from a web page.
How could we do that?

1)We generated links like :
http://127.0.0.1:58997/download/-1584127920xe48f773bd522664b1f94d7c926e144bb

2)We opened an Httpserver listening the port specified.

3)User was seeing link in web page.But link was triggering our client program.

4)Program was downloading file parts from server,decrypting them
and writing to response of http request.

Below is piece of codes for this logic.It is not complete but enough.

import java.io.IOException ;
import java.net.InetSocketAddress ;
import java.util.HashMap ;
import java.util.Map ;

import com.sun.net.httpserver.HttpHandler ;
import com.sun.net.httpserver.HttpServer ;

public class KEmbeddedHttpServer 
{
    protected HttpServer server ;

    protected int port ;

    protected Map handlerMap = new HashMap<>( ) ;

    public KEmbeddedHttpServer( int port )
    {
        this.port = port ;
    }

    public HttpServer getServer( )
    {
        return this.server ;
    }

    public int getPort( )
    {
        return this.port ;
    }

    public void setPort( int port )
    {
        this.port = port ;
    }

    public void addHandler( String context, HttpHandler handler )
    {
        this.handlerMap.put( context, handler ) ;
    }

    public void start( ) throws IOException
    {
        this.server = HttpServer.create( new InetSocketAddress( this.port ), 0 ) ;

        for( String context : this.handlerMap.keySet( ) )
        {
            this.server.createContext( "/" + context, this.handlerMap.get( context ) ) ;
        }

        this.server.setExecutor( null ) ; // creates a default executor

        this.server.start( ) ;
    }
}



public void doHandleRequest( final HttpExchange httpExchange ) throws IOException
    {
        String requestPath = httpExchange.getRequestURI( ).getPath( ) ;
        
            try
            {
                

                final String fileName = decFileMeta.substring( 0, decFileMeta.indexOf( ", @" ) ).trim( ) ;

                final OutputStream os = httpExchange.getResponseBody( ) ;

                IKObserver observer = new IKObserver( )
                {
                    @Override
                    public Boolean onAction( String action, byte[ ] data )
                    {
                        try
                        {
                            if( BLOCK_READ.equals( action ) )
                            {
                                os.write( data ) ;
                            }
                            else if( START_OF_OPERATION.equals( action ) )
                            {
                                httpExchange.getResponseHeaders( ).add( "Content-Disposition", "attachment; filename=" + fileName ) ;
                                httpExchange.getResponseHeaders( ).add( "Transfer-encoding", "chunked" ) ;
                                httpExchange.sendResponseHeaders( 200, 0 ) ;
                            }
                            else if( END_OF_OPERATION.equals( action ) )
                            {
                                if( os != null )
                                {
                                    os.flush( ) ;
                                    os.close( ) ;
                                }
                            }

                            return Boolean.TRUE ;
                        }
                        catch( Exception ex )
                        {
                            ex.printStackTrace( ) ;
                            return false ;
                        }
                    }
                } ;


                
            }
            catch( Exception e )
            {
                e.printStackTrace( ) ;
                e.printStackTrace( new PrintWriter( this.writer ) ) ;
                httpExchange.getResponseHeaders( ).add( "Content-Disposition", "inline; filename=error.html" ) ;
                httpExchange.sendResponseHeaders( 500, this.baos.size( ) ) ;
            }

        

    }


 

How to write a zero knowledge server for encryption?

In our project for encryption we needed to make server as blind as possible.

We applied below algorithms for this purpose.

1) Server must not know which files it is storing.
Put files in parts.
Place them at random locations on server.
Put fake blocks.

2)Server file parts must be meaningless.
For attacking for basic files(raw text files) one can check occurring patterns for frequency analysis.
So zip files to decrease entropy.

3)While checking database attackers must not understand anything.
For example think you have a column as user id.

If attacker sees column id = 3 he will understand all files of user 3.
So every column must be kept encrypted.
But a hash or md5 of 3 will always be same .Ex : 344jkfjkdf994jjfjf
So an attacker can understand these files belong to same user.

So what is a good candidate for every row to have different values for same data?
Row id . Put row id into hashing or AES algorithm .

But still there is a pattern.
User Id + Row id
either post or prefix can give a clue.

So put time stamp at beginning.

Date.now + user id + row id

Every user must understand his files but not other people' files.
So AES this with user AES key


select CAST( AES_DECRYPT( UNHEX( enc_column), ? ) as char ) as user_info

FROM anytable_encyrpted HAVING user_info = concat( 'userid=(', ?, '),id=(', anytable_encyrpted_id , ')' ) " ;

? are parameters as follows :
User AES key, and user id

How to simulate a thumb driver in local

In a project we needed to simulate a thumb driver for multi user system ,
share public keys over network.


A thumb driver does not share it's private key.
We can simulate a thumb driver in our local.


Project will enable users of system to use their local laptops or
usb drives as thumb drive.

So let's write basic principles for this simulation.
1)All encryption decryption must occur at local machine.

2)All data send over network must be encrypted

3)User public keys must be kept at server.(Public key distribution server better to
be on a different server than data server)

4)RSA is slow for file encryption.Encrypt Files with AES.
Encrypt AES keys with every user's public key put to server.
***You have one door,one key.
for n users clone key and put in a box only that target user have key(user's private key)

Lucene Tester

There is no need to explain why someone needs Lucene .
There are also lots of samples over net. I am just putting our sample if anyone
encounters this link.

import java.io.File ;
import java.io.Reader ;
import java.io.Serializable ;
import java.io.StringReader ;
import java.util.HashMap ;
import java.util.List ;

import org.apache.lucene.analysis.Analyzer ;
import org.apache.lucene.analysis.standard.StandardAnalyzer ;
import org.apache.lucene.document.Document ;
import org.apache.lucene.document.Field ;
import org.apache.lucene.index.CorruptIndexException ;
import org.apache.lucene.index.IndexReader ;
import org.apache.lucene.index.IndexWriter ;
import org.apache.lucene.index.IndexWriter.MaxFieldLength ;
import org.apache.lucene.index.Term ;
import org.apache.lucene.queryParser.QueryParser ;
import org.apache.lucene.search.IndexSearcher ;
import org.apache.lucene.search.Query ;
import org.apache.lucene.search.ScoreDoc ;
import org.apache.lucene.search.Searcher ;
import org.apache.lucene.search.TermQuery ;
import org.apache.lucene.search.TopDocs ;
import org.apache.lucene.search.similar.MoreLikeThis ;
import org.apache.lucene.search.spell.Dictionary ;
import org.apache.lucene.search.spell.LuceneDictionary ;
import org.apache.lucene.search.spell.SpellChecker ;
import org.apache.lucene.store.Directory ;
import org.apache.lucene.store.FSDirectory ;
import org.apache.lucene.util.Version ;

public class YLuceneTester
{


    private final String indexDir = "D:\\indexDir" ;

    private final String spellDirPath = "D:\\spellDir" ;

    /**
     * create index
     */
    public boolean createIndex( ) throws Exception
    {
        //        if( true == ifIndexExist( ) )
        //        {
        //            return true ;
        //        }
        //        File dir = new File(dataDir);
        //        if(!dir.exists()){
        //            return false;
        //        }

        //File[] htmls = dir.listFiles();

        Directory fsDirectory = FSDirectory.open( new File( this.indexDir ) ) ;
        Analyzer analyzer = new StandardAnalyzer( Version.LUCENE_33 ) ;
        IndexWriter indexWriter = new IndexWriter( fsDirectory, analyzer, true, MaxFieldLength.UNLIMITED ) ;

        addDocument( indexWriter ) ;

        indexWriter.optimize( ) ;
        indexWriter.close( ) ;

        IndexReader indexReader = null ;
        try
        {
            indexReader = IndexReader.open( fsDirectory ) ;
            Dictionary dictionary = new LuceneDictionary( indexReader, "trans" ) ;
            FSDirectory spellDir = FSDirectory.open( new File( this.spellDirPath ) ) ;
            SpellChecker spellChecker = new SpellChecker( spellDir ) ;
            spellChecker.indexDictionary( dictionary ) ;
            spellChecker.close( );
        }
        finally
        {
            if( indexReader != null )
            {
                indexReader.close( ) ;
            }
        }
        return true ;

    }

    /**
     * Add one document to the Lucene index
     * @throws Exception 
     * @throws CorruptIndexException 
     */
    public void addDocumentDB( IndexWriter indexWriter ) throws CorruptIndexException, Exception
    {
        YOrganization org = YOrganization.getTopLevelOrganization( "TXG100" ) ;

        String hql = " Select y.trans,y.id FROM YEntityTranslation y where y.organization.id =  " + org.getId( ) ;

        HashMap parameters = new HashMap( ) ;

        List existingCatalogData = ( List )HibernateUtils.execHQL( hql, parameters, 0, 1000 ) ;          for( Object[ ] datas : existingCatalogData )         {             String trans = ( String )datas[ 0 ] ;             if( YClientUtils.isBlankTrim( trans ) )                 continue ;              System.err.println( trans ) ;             Document document = new Document( ) ;             //document.add( new Field( "path", path, Field.Store.YES, Field.Index.NO ) ) ;             document.add( new Field( "trans", trans, Field.Store.YES, Field.Index.ANALYZED ) ) ;              indexWriter.addDocument( document ) ;         }      }          public void addDocument( IndexWriter indexWriter ) throws CorruptIndexException, Exception     {         String[] items = new String[]{"African lion","African wild cat","African wild dog","dog","cat","lion"};                  for( String item : items )         {              Document document = new Document( ) ;             document.add( new Field( "trans", item, Field.Store.YES, Field.Index.ANALYZED ) ) ;              indexWriter.addDocument( document ) ;         }      }      public Query suggest( String queryString ,int distance) throws Exception     {         try         {             Directory fsDirectory = FSDirectory.open( new File( this.spellDirPath ) ) ;             SpellChecker spellChecker = new SpellChecker( fsDirectory ) ;             if( spellChecker.exist( queryString ) )             {                 return null ;             }             String[ ] similarWords = spellChecker.suggestSimilar( queryString, distance ) ;             if( similarWords.length == 0 )             {                 return null ;             }              System.err.println( " Term = " + queryString + " Suggestions :" ) ;             for( String similarWord : similarWords )             {                 System.err.println( " ) " + similarWord ) ;             }              return new TermQuery( new Term( "trans", similarWords[ 0 ] ) ) ;         }         catch( Exception e )         {             throw new Exception( e.getMessage( ) ) ;         }     }      public void searchIndex( String[ ] queryStrings ) throws Exception     {         Searcher searcher = new IndexSearcher( FSDirectory.open( new File( this.indexDir ) ) ) ;         QueryParser parser = new QueryParser( Version.LUCENE_CURRENT, "trans", new StandardAnalyzer( Version.LUCENE_CURRENT ) ) ;         for( String queryString : queryStrings )         {             System.out.println( "nsearching for: " + queryString ) ;             Query query = parser.parse( queryString ) ;             TopDocs results = searcher.search( query, 10 ) ;             System.out.println( "total hits: " + results.totalHits ) ;             ScoreDoc[ ] hits = results.scoreDocs ;             for( ScoreDoc hit : hits )             {                 Document doc = searcher.doc( hit.doc ) ;                 System.out.printf( "%5.3f %sn \n", hit.score, doc.get( "trans" ) ) ;             }         }         searcher.close( ) ;     }       /**      * judge if the index exists already      */     public boolean ifIndexExist( )     {         File directory = new File( this.indexDir ) ;         if( 0 < directory.listFiles( ).length )
        {
            return true ;
        }
        else
        {
            return false ;
        }
    }

    public String getIndexDir( )
    {
        return this.indexDir ;
    }


    public Query parse( String queryString ) throws Exception
    {
        QueryParser queryParser = new QueryParser( Version.LUCENE_CURRENT, "trans", new StandardAnalyzer( Version.LUCENE_CURRENT ) ) ;
        queryParser.setDefaultOperator( QueryParser.AND_OPERATOR ) ;
        return queryParser.parse( queryString ) ;
    }

    public void search( String queryString ,int distance ) throws Exception
    {
        long startTime = System.currentTimeMillis( ) ;
        IndexSearcher is = null ;
        FSDirectory spellDir = FSDirectory.open( new File( this.spellDirPath ) ) ;
        Directory fsDirectory = FSDirectory.open( new File( this.indexDir ) ) ;

        int minimumHits = 100 ;
        int minimumScore = 5 ;

        try
        {
            is = new IndexSearcher( fsDirectory ) ;
            Query query = parse( queryString ) ;

            TopDocs tdocs = is.search( query, 100 ) ;

            //Hits hits = is.search( query ) ;

            //            for( ScoreDoc sdoc :  tdocs.scoreDocs )
            //            {
            //                sdoc.
            //            }

            String suggestedQueryString = null ;
            if( tdocs.totalHits < minimumHits || tdocs.getMaxScore( ) < minimumScore )
            {
                Query didYouMean = suggest( queryString ,distance) ;
                if( didYouMean != null )
                {
                    suggestedQueryString = didYouMean.toString( "trans" ) ;
                }
            }

            long endTime = System.currentTimeMillis( ) ;

            //return new SearchResult( extractHits( hits ), hits.length( ), endTime - startTime, queryString, suggestedQueryString ) ;
        }
        finally
        {
            if( is != null )
            {
                is.close( ) ;
            }
        }
    }

    public void moreLikeThis( String text ) throws Exception
    {
        Directory fsDirectory = FSDirectory.open( new File( this.indexDir ) ) ;

        IndexReader indexReader = IndexReader.open( fsDirectory ) ;

        //        FuzzyLikeThisQuer flt = new FuzzyLikeThisQuery( 50, new StandardAnalyzer( ) ) ;
        //        flt.addTerms( "product critical update", "title", 0.75f, FuzzyQuery.defaultPrefixLength ) ;
        //        BooleanQuery q = ( BooleanQuery )flt.rewrite( r ) ;
        //        int minNumClauseMatches = Math.round( q.clauses( ).size( ) * 0.5f ) ;
        //        q.setMinimumNumberShouldMatch( minNumClauseMatches ) ;

        IndexSearcher is = new IndexSearcher( FSDirectory.open( new File( this.indexDir ) ) ) ;

        MoreLikeThis mlt = new MoreLikeThis( indexReader ) ;
        mlt.setFieldNames( new String[ ] { "trans" } ) ;

        mlt.setMinWordLen( 2 ) ;
        mlt.setBoost( true ) ;

        Reader reader = new StringReader( text ) ;

        //Create the query that we can then use to search the index
        Query query = mlt.like( reader ) ;

        //Search the index using the query and get the top 5 results
        TopDocs topDocs = is.search( query, 5 ) ;

        //Create an array to hold the quotes we are going to
        //pass back to the client

        for( ScoreDoc scoreDoc : topDocs.scoreDocs )
        {
            //This retrieves the actual Document from the index using
            //the document number. (scoreDoc.doc is an int that is the

            System.err.print( "--" + scoreDoc.toString( ) ) ;
        }
        
        is.close( );

    }
    
    public static void init()
    {
        YLuceneTester luceneTester = new YLuceneTester( ) ;
        try
        {
            luceneTester.createIndex( ) ;

            //luceneTester.searchIndex( new String[ ] { "Cleaner" } ) ;
            //TermQuery q = ( TermQuery )luceneTester.suggest( "Claner" ) ;
            //q.extractTerms( terms )

            //luceneTester.moreLikeThis( "Clean" ) ;

            //            luceneTester.search( "Cleaner" ) ;
            //            luceneTester.search( "Cordless " ) ;
            //
            //            luceneTester.suggest( "Cleane" ) ;
            //            luceneTester.suggest( "Clean" ) ;
            //            luceneTester.suggest( "Clnr" ) ;

        }
        catch( Exception e )
        {
            e.printStackTrace( ) ;
        }
    }
    
    public static void tests()
    {
        YLuceneTester luceneTester = new YLuceneTester( ) ;
        try
        {

//            luceneTester.searchIndex( new String[ ] { "Afri" } ) ;
//            luceneTester.searchIndex( new String[ ] { "African" } ) ;
//            luceneTester.searchIndex( new String[ ] { "Africax" } ) ;
//            TermQuery q = ( TermQuery )luceneTester.suggest( "Claner" ) ;
//            q.extractTerms( terms )

            //luceneTester.moreLikeThis( "dog" ) ;

                        luceneTester.search( "Afrieen" ,1 ) ;
                        luceneTester.search( "Afrieen" ,1 ) ;
                        luceneTester.search( "Afrieen" ,1 ) ;
            //            luceneTester.search( "Cordless " ) ;
            //
                        luceneTester.suggest( "Afrieen",2 ) ;
                        luceneTester.suggest( "lion" ,2) ;
            //            luceneTester.suggest( "Clnr" ) ;

        }
        catch( Exception e )
        {
            e.printStackTrace( ) ;
        }
    }

    public static void main( String[ ] args )
    {
        //HibernateUtils._configFileName = "hibernate.hqltest.xml" ;
        
        //init( );
        
        tests( );



    }
}

Display Current Sequence of All tables In xhtml

At a project Postgre sequences were cached and sometimes at server restarts we were seeing
strange behaviours. Also when someone inserts a sequence manually we were again having difficulties.
Here is simple page to see your database state.

public ArrayList>  initDbStateList(List            tableNames ,HashMap tableNamePrimary )
   {
	   ArrayList> data = new ArrayList>();
	   
	   
      
      for( String tname : tableNames )
      {
         HashMap map = new HashMap();
         
         map.put("tname", tname);
         map.put("seqid", 0L);
         map.put("maxid", 0L);
         
         try {
            
         
         
         String sql = "select nextval('MYDB."+ tname+"_sequence"+"');"; 
         Long seqid = -1L; 
                  
         try {
            seqid = queryForLong(sql);
         }
         catch (Exception e) {
            logger.error(e, e);
         }
          
         
         map.put("seqid", seqid);
         
         String maxsql = " select max("+tableNamePrimary.get(tname)+") from nufus."+tname+"; ";          
         Long maxid = queryForLong(maxsql);
         map.put("maxid", maxid);
         
         if( seqid != null && maxid != null )
         {
            if( seqid < maxid)
            {
               map.put("problematic", "YES");
            }
         }
         
         
         data.add(map);
         }
         catch (Exception e) {
            map.put("problematic", "NONEXISTENT");
            e.printStackTrace();
         }
      
      
	   }
     
	   
      return data;
   }

 

And datatable to display the result will be like :

JSF Style Verifier

In a JSF project we had a very long list of principles for UI components.

Example : p:panel inside p:fieldset must have style ed_borderless

I was told to check screens for these things. Unfortunately I am not good at
design things. Most people were able to say what is wrong in a panel at 1st glance.
But I was not.

I taught i can write a verifier for style and process all of pages at once.

One more thing about project was ,it's GUI was so heavy so there was deep
path for components.

p:panelGrid : ->p:column : ->p:row : ->p:panelGrid :

I put a search depth parameter to check for under each component.


Program will geneate an output like below :


p:panel inside h:form must have reset_uipanel : missing style (reset_uipanel) having ed_borderless
>>> h:form : mytForm->p:dialog : personDialog->h:form : form->ui:define : ->ui:composition : ->h:body : ->f:view : ->html : ->

It tells which style is missing and missing path.

import java.io.File ;
import java.util.ArrayList ;
import java.util.HashMap ;
import java.util.HashSet ;

import javax.xml.parsers.DocumentBuilder ;
import javax.xml.parsers.DocumentBuilderFactory ;

import org.w3c.dom.Document ;
import org.w3c.dom.Element ;
import org.w3c.dom.NamedNodeMap ;
import org.w3c.dom.Node ;
import org.w3c.dom.NodeList ;



public class StyleVerifier
{

    public static String NODE_Panel = "p:panel" ;

    public static String NODE_Panelgrid = "p:panelgrid" ;

    protected StringBuffer logs = new StringBuffer( ) ;

    public int globalCheckDepth = -1 ;

    public StringBuffer getLogs( )
    {
        return this.logs ;
    }

    public void setLogs( StringBuffer logs )
    {
        this.logs = logs ;
    }

    public void getChildsOfType( Node node, String type, ArrayList res )
    {

        if( res == null )
        {
            res = new ArrayList( ) ;
        }

        NodeList nodeList = node.getChildNodes( ) ;

        for( int i = 0; i < nodeList.getLength( ); i++ )
        {

            Node n = nodeList.item( i ) ;

            System.err.println( " verifying " + n.getNodeName( ) ) ;

            if( n.getNodeName( ).equals( type ) )
            {

                Node actualNode = n.getFirstChild( ) ;

                if( actualNode != null )
                {
                    res.add( actualNode ) ;
                }
            }

            getChildsOfType( n, type, res ) ;
        }

    }

    public String getParentPath( Element element )
    {

        if( !( element.getParentNode( ) instanceof Element ) )
            return "" ;

        Element par = ( Element )element.getParentNode( ) ;

        if( par == null )
            return "" ;

        String nodDisp = par.getNodeName( ) + " : " + par.getAttribute( "id" ) ;

        return nodDisp + "->" + getParentPath( par ) ;
    }

    //breakingParent  is for items like panel.
    //If panel is inside h:form before fieldset we can not say it is under fieldset.
    public Element hasParentOfType( Element element, String parentType, String breakingParent, int checkDepth )
    {
        if( checkDepth == 0 )
            return null ;

        if( !( element.getParentNode( ) instanceof Element ) )
            return null ;

        Element par = ( Element )element.getParentNode( ) ;

        if( par == null )
            return null ;

        String nodnam = par.getNodeName( ) ;

        if( breakingParent != null && breakingParent.equals( nodnam ) )
        {
            return null ;
        }

        if( parentType.equals( nodnam ) )
        {
            return par ;
        }

        checkDepth-- ;
        return hasParentOfType( par, parentType, breakingParent, checkDepth ) ;
    }

    public boolean isPanel( Element element )
    {
        String nodnam = element.getNodeName( ) ;

        System.out.println( nodnam + "=" + element.getAttribute( "styleClass" ) ) ;

        if( NODE_Panel.equalsIgnoreCase( nodnam ) )
        {
            return true ;
        }
        return false ;
    }

    public boolean isType( Element element, String type )
    {
        String nodnam = element.getNodeName( ) ;

        if( type.equalsIgnoreCase( nodnam ) )
        {
            return true ;
        }
        return false ;
    }

    public void validateFile( File fileToVerify ) throws Exception
    {

        if( !fileToVerify.getName( ).endsWith( ".xhtml" ) )
            return ;

        System.err.println( "Parse beginnig" ) ;
        
        //"D:\verify\webapp\"
        

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance( ) ;
        dbf.setNamespaceAware( false ) ;
        dbf.setValidating( false ) ;
        dbf.setFeature( "http://xml.org/sax/features/namespaces", false ) ;
        dbf.setFeature( "http://xml.org/sax/features/validation", false ) ;
        dbf.setFeature( "http://apache.org/xml/features/nonvalidating/load-dtd-grammar", false ) ;
        dbf.setFeature( "http://apache.org/xml/features/nonvalidating/load-external-dtd", false ) ;

        DocumentBuilder db = dbf.newDocumentBuilder( ) ;
        Document document = db.parse( fileToVerify ) ;

        NodeList alllist = document.getElementsByTagName( "*" ) ;

        System.err.println( "Parse step 2" ) ;

        for( int i = 0; i < alllist.getLength( ); i++ )
        {

            Element element = ( Element )alllist.item( i ) ;

            verifyStyleUnderParent( element, "p:panel", "h:form", "p:fieldset", "reset_uipanel", "p:panel inside h:form must have reset_uipanel", this.globalCheckDepth ) ;

            System.err.println( "Parse step 3" ) ;

            verifyStyleUnderParent( element, "p:panel", "p:fieldset", "h:form", "ed_borderless", "p:panel inside p:fieldset must have ed_borderless", this.globalCheckDepth ) ;

            System.err.println( "Parse step 4" ) ;

            verifyStyleUnderParent( element, "p:panelgrid", "p:panelgrid", null, "ed_gridcellborderless", "p:panelgrid inside p:panelgrid must have ed_gridcellborderless", this.globalCheckDepth ) ;

            System.err.println( "Parse step 5" ) ;

            //
            HashMap styleValues = new HashMap( ) ;
            styleValues.put( "closable", "false" ) ;

            HashSet notNullStyles = new HashSet( ) ;
            notNullStyles.add( "header" ) ;

            verifyStyleMustHave( element, "p:dialog", styleValues, notNullStyles, "Dialog not having proper rules" ) ;
        }

    }




    public String verifyStyleUnderParent( Element element, String mytype, String parenttype, String breakingParent, String mustHaveStyle, String breakMessage, int checkDepth )
    {

        boolean isTargetType = isType( element, mytype ) ;
        if( isTargetType )
        {
            boolean isInside = hasParentOfType( element, parenttype, breakingParent, checkDepth ) != null ;

            if( isInside )
            {

                String styleClass = element.getAttribute( "styleClass" ) ;
                if( styleClass == null || !mustHaveStyle.equals( styleClass ) )
                {

                    String msg = element.getAttribute( "id" ) + " missing style (" + mustHaveStyle + ") having " + styleClass + "\n" ;
                    msg += ">>> " + getParentPath( element ) + "\n\n" ;

                    this.logs.append( breakMessage + " : " + msg ) ;
                    this.logs.append( getItemXML( element ) ) ;
                    
                    return msg ;
                }
            }
        }

        return null ;
    }

    
    public String getItemXML( Element element )
    {
        NamedNodeMap nameNodeMap = element.getAttributes( ) ;

        String s = "<" + element.getNodeName( ) + " " ;
        for( int i = 0; i < nameNodeMap.getLength( ); ++i )
        {
            Node attr = nameNodeMap.item( i ) ;
            s += " " + attr.getNodeName( ) + "=\"" + attr.getNodeValue( ) + "\"" ;
        }
        return s + " >\n\n" ;

    }

    //Checks whether element have stated styles with stated values
    public String verifyStyleMustHave( Element element, String mytype, HashMap styleValues, HashSet notNullStyles, String breakMessage ) throws Exception
    {

        String missingStyles = "" ;
        boolean isTargetType = isType( element, mytype ) ;
        if( isTargetType )
        {
            for( String key : styleValues.keySet( ) )
            {
                String styleClass = element.getAttribute( key ) ;
                String mustHaveStyle = styleValues.get( key ) ;
                if( styleClass == null || !mustHaveStyle.equals( styleClass ) )
                {

                    String msg = element.getAttribute( "id" ) + " , " + key + " must style (" + mustHaveStyle + ") having " + styleClass + "\n" ;
                    msg += ">>> " + getParentPath( element ) + "\n\n" ;

                    missingStyles += msg ;
                }
            }

            for( String key : notNullStyles )
            {
                String styleClass = element.getAttribute( key ) ;
                if( styleClass == null )
                {

                    String msg = "id= " + element.getAttribute( "id" ) + " , " + key + " missing style   \n" ;
                    msg += ">>> " + getParentPath( element ) + "\n\n" ;

                    missingStyles += msg ;
                }
            }
        }

        if( missingStyles != null && missingStyles.trim( ).length( ) > 0 )
        {
            this.logs.append( getItemXML( element ) ) ;
            this.logs.append( breakMessage + " : " + missingStyles ) ;

        }

        return null ;
    }

    //h:form içerisindeki p:panel reset_uipanel
    //fieldset içerisindeki p:panel        ed_borderless
    //p:panelgrid içerisindeki p:panelgrid        ed_gridcellborderless

    public void verifyFileOrDirectory( File fileOrDir ) throws Exception
    {

        if( fileOrDir.isDirectory( ) )
        {
            File[ ] subitems = fileOrDir.listFiles( ) ;

            for( File subitem : subitems )
            {

                this.verifyFileOrDirectory( subitem ) ;
            }

        }
        else
        {
            this.logs.append( fileOrDir.getName( ) + "\n\n" ) ;
            
            String absolutePath = fileOrDir.getAbsolutePath( );
            String plink = "\nlocalhost:7001/aydes" +absolutePath.substring( absolutePath.indexOf( "webapp" ) +"webapp".length( ) );
            plink = plink.replaceAll( "xhtml", "jsf" ) + "\n";
            
            this.logs.append( plink + "\n\n" ) ;
            
            System.err.println( fileOrDir.getAbsolutePath( ) ) ;

            if( !fileOrDir.getName( ).endsWith( ".xhtml" ) )
                return ;

            //validateFile( FileUtils.fileToString( fileOrDir.getAbsolutePath( ), "utf-8" ) );

            validateFile( fileOrDir ) ;

            
        }

    }

    public int getGlobalCheckDepth( )
    {
        return this.globalCheckDepth ;
    }

    public void setGlobalCheckDepth( int globalCheckDepth )
    {
        this.globalCheckDepth = globalCheckDepth ;
    }

    public static void runForDepth( int depth, String path )
    {
        StyleVerifier uiVerifier_ByXml = new StyleVerifier( ) ;
        try
        {
            uiVerifier_ByXml.setGlobalCheckDepth( depth ) ;
            uiVerifier_ByXml.verifyFileOrDirectory( new File( path ) ) ;
            
            FileUtils.stringToFile( "D:\\verify_log_" + uiVerifier_ByXml.globalCheckDepth + ".txt", uiVerifier_ByXml.logs.toString( ), "utf-8", true ) ;
            uiVerifier_ByXml.logs.setLength( 0 ) ;

        }
        catch( Exception e )
        {
            // TODO Auto-generated catch block
            e.printStackTrace( ) ;
        }
    }

    public static void main( String[ ] args )
    {

        String sample = "D:\\verify" ;

        StyleVerifier uiVerifier_ByXml = new StyleVerifier( ) ;
        try
        {
            runForDepth( -1, sample ) ;
            runForDepth( 1, sample ) ;
            runForDepth( 2, sample ) ;
            runForDepth( 3, sample ) ;
            runForDepth( 4, sample ) ;
        }
        catch( Exception e )
        {
            e.printStackTrace( ) ;
        }

        System.err.println( uiVerifier_ByXml.logs.toString( ) ) ;

    }

}

Lazy load exception , Re-using invalid objects

When you get an exception on hibernate session you can not use those objects again.
Their session is invalidated. You must close session and not use objects loaded in that session.
However for some reasons(logging,marking) You need to use them.


What you can do is,load all objects as proxies.
Below code is not complete(reference methods not here) but it is clear and you can easily understand the idea.

    public void refreshBeans( )
    {
        String[ ] beans = this.getBeanNames( ) ;

        for( String beanName : beans )
        {
            YBean val = ( YBean )this.getFieldValue( beanName ) ;

            if( val != null && val.getId( ) != null && val.getId( ).intValue( ) != 0 )
            {
                YBean newbean = HibernateUtils.loadObjectProxyById( ReflectionUtils.getRealBeanClass( val.getClass( ) ), val.getId( ) ) ;
                this.setFieldValue( beanName, newbean ) ;
            }
        }
    }


 

Trace All opened sessions on hibernate

For bench marking issues we needed to trace all opened sessions by hibernate.
We were also tracing when it was closed and which objects were loaded during session.
Idea was simple.


Exception ex = new Exception( "Session opened on " + CalendarUtils.now( ) ) ;


This uniquely identifies the current path of execution and since date is added it is unique.



Example : below code puts a mark a debug object on transaction trace pool. So that we can find
when begined the problematic transaction began.

 public static void beginTransaction( )
    {
        getSession( ).beginTransaction( ) ;

        Exception ex = new Exception( "Transaction began on " + CalendarUtils.now( ) ) ;

        Integer code = getSessionStackTraceIdent( ).get( ) ;

        getTransactionTracePool( ).put( code, ex ) ;

        getTransactionTimestampPool( ).put( code, CalendarUtils.now( ) ) ;

        System.err.println( "Transaction Open in beginTransaction " + getSession( ).getTransaction( ).hashCode( ) ) ;
    }
 

Dump objects in current hibernate session

Sometimes u want to monitor all objects loaded in current hibernate session. For this we get "persistenceContext" from hibernate session. Since it is not visible we played with visibility. Below is a nice very handy piece of code doing this. You can this method at commit of hibernate session to check how many objects loaded during transaction. Most of time you will be very surprised. It will help you to optimize your code.

 public static Object getField( Object instance, String name ) throws Exception
    {
        Field f = instance.getClass( ).getDeclaredField( name ) ;
        f.setAccessible( true ) ;
        return f.get( instance ) ;
    }


public static String printHibernateEntities( )
    {
        final Session s = HibernateManager.getSession( ) ;

        if( s == null )
            return null ;

        StringBuffer sbf = new StringBuffer( ) ;

        List result = null ;
        try
        {
            StatefulPersistenceContext spconContext = ( StatefulPersistenceContext )getField( s, "persistenceContext" ) ;
            Map entities = spconContext.getEntityEntries( ) ;

            result = new ArrayList( entities.size( ) ) ;
            for( Iterator it = entities.values( ).iterator( ); it.hasNext( ); )
            {
                Object o = it.next( ) ;

                String className = ( String )getField( o, "entityName" ) ;

                if( className.indexOf( "." ) > 0 )
                    className = className.substring( className.lastIndexOf( '.' ) + 1, className.length( ) ) ;

                Integer id = ( Integer )getField( o, "id" ) ;

                org.hibernate.engine.EntityEntry e = ( org.hibernate.engine.EntityEntry )o ;

                result.add( className + ": " + id + " = " + o.hashCode( ) + ", key: " + ( e.getId( ) == null ? "N/A" : e.getEntityKey( ) ) + ", status: " + e.getStatus( ) ) ;
            }



            for( int i = 0; i < result.size( ); i++ )
            {

                sbf.append( i + " ) " + result.get( i ) + "\n" ) ;
            }

            if( !FileUtils.isUnix( ) )
            {
                System.out.println( "printHibernateEntities" ) ;
                System.out.println( sbf.toString( ) ) ;
            }
        }
        catch( Exception e )
        {
            e.printStackTrace( ) ;
            YEmergencyEmail.sendErrorMessage( e, "Can not get a dump of printHibernateEntities ", null ) ;
        }

        return sbf.toString( ) ;
    }

illegally attempted to associate a proxy with two open Sessions

We were having this exception in a very complicated process where hundreds of objects were being saved or updated in a single work unit.(No it was natural system was so) If this happens in simple block or hibernate gives any clue it is easy to solve. But sometimes there is no clue so we wrote a DefaultSaveOrUpdateEventListener. As we guess it is because of parentsByChild ( Parent entities cache by their child for cascading ) map at PersistenceContext we wrote a code at bottom. It checks for the item that get exception and which beans are waiting for cascade. This revealed us the problem.

protected static void initSaveOrUpdateEventListenerHook( Configuration config )
    {
        List l = new ArrayList( ) ;
        SaveOrUpdateEventListener[ ] listeners = config.getEventListeners( ).getSaveOrUpdateEventListeners( ) ;
        l.add( new DefaultSaveOrUpdateEventListener( )
        {

            

            @Override
            public void onSaveOrUpdate( org.hibernate.event.SaveOrUpdateEvent arg0 )
            {
                try
                {
                    super.onSaveOrUpdate( arg0 ) ;
                }
                catch( RuntimeException e )
                {
                    e.printStackTrace( ) ;

                    try
                    {
                        Object pc = arg0.getSession( ).getPersistenceContext( ) ;

                        Map m = ( Map )getField( pc, "parentsByChild" ) ;

                        // System.err.println( "Map size: " + m.size( ) + ", " + m ) ;

                        StringBuilder sb = new StringBuilder( ) ;

                        int cnt = 0 ;

                        Map.Entry[] list = IdentityMap.concurrentEntries( m ) ;

                        for( Map.Entry me : list )
                        {
                            YBean childBean = ( YBean )me.getKey( ) ;
                            YBean parentBean = ( YBean )me.getValue( ) ;

                            sb.append( "item " + cnt++ + " is " + parentBean.getClass( ).getSimpleName( ) + "#" + parentBean.getId( ) + ", child is " + childBean.getClass( ).getSimpleName( ) + "#" + childBean.getId( ) + "
\n" ) ;
                        }

                        System.err.println( "the child parent Map is " + sb ) ;

                    }
                    catch( Exception e1 )
                    {
                        e1.printStackTrace( ) ;
                        YEmergencyEmail.sendErrorMessage( e1, "Error on child parent map mailing", null ) ;
                    }

            } ;

            @Override
            protected boolean reassociateIfUninitializedProxy( Object object, SessionImplementor source )
            {
                // System.err.println( "Object is ************* " + object ) ;
                try
                {
                    return super.reassociateIfUninitializedProxy( object, source ) ;
                }
                catch( RuntimeException e )
                {
                    e.printStackTrace( ) ;

                    try
                    {
                        YBean bean = ( YBean )object ;

                        String uid = "UID_" + System.nanoTime( ) ;

                        int hashCode = -1 ;
                        if( bean instanceof HibernateProxy )
                        {
                            HibernateProxy prox = ( HibernateProxy )bean ;

                            hashCode = prox.getHibernateLazyInitializer( ).getSession( ).hashCode( ) ;

                            Exception sessionTrace = HibernateManager.getSessionTracePool( ).get( hashCode ) ;

                            System.err.println( "uid : ========================= session is from =========================== " ) ;
                            sessionTrace.printStackTrace( ) ;

                            YEmergencyEmail.sendErrorMessage( sessionTrace, "Session " + hashCode + "uid 3:" + uid + "session is from", "uid:" + uid + " session is from reassociateIfUninitializedProxy " ) ;
                        }

                    }
                    catch( Exception e2 )
                    {
                        e2.printStackTrace( ) ;
                        YEmergencyEmail.sendErrorMessage( e2, "Error on cachting exception in reassociateIfUninitializedProxy", null ) ;
                    }

                    throw e ;
                }
            }
        } ) ;

        l.addAll( Arrays.asList( listeners ) ) ;
        SaveOrUpdateEventListener[ ] newListeners = l.toArray( new SaveOrUpdateEventListener[ l.size( ) ] ) ;
        config.getEventListeners( ).setSaveOrUpdateEventListeners( newListeners ) ;
    }

Connecting to SFTP

SFTP is a network protocol that provides file operation over network .

It  runs on a secure channel.

Below is a sample code for SFTP actions.

 protected JSch jsch = null ;



    protected Session session = null ;



    protected ChannelSftp sftpChannel = null ;





    /** A convenience method for connecting and logging in */

    public boolean connectAndLogin( String host, String userName, String password, String privateKey, String publicKey ) throws IOException, JSchException

    {

        boolean success = false ;



        try

        {

            System.err.println( "Tryign to SECURELY connect " + host + " with user name " + userName + ", password: ************ " ) ;



            this.jsch = new JSch( ) ;



            // will this work?

            java.security.Security.removeProvider( "SunPKCS11-Solaris" ) ;



            JSch.setLogger( this ) ;



            if( !YClientUtils.isBlankTrim( privateKey ) && !YClientUtils.isBlankTrim( publicKey ) )

            {

                this.jsch.addIdentity( userName, privateKey.getBytes( "utf8" ), publicKey.getBytes( "utf8" ), password == null ? null : password.getBytes( "uft8" ) ) ;

            }

            else

            {

                throw new IllegalArgumentException( "Private and public keys must not be null" ) ;

            }



            this.session = this.jsch.getSession( userName, host ) ;



            this.session.setConfig( "StrictHostKeyChecking", "no" ) ;



            this.session.setConfig( "PreferredAuthentications", "publickey" ) ;

            this.session.setTimeout( 120000 ) ;

            

            this.session.connect( ) ;



            Channel channel = this.session.openChannel( "sftp" ) ;

            channel.connect( ) ;



            this.sftpChannel = ( ChannelSftp )channel ;

            success = true ;

        }

        catch( IOException e )

        {

            e.printStackTrace( ) ;

            success = false ;

            throw e ;

        }

        catch( JSchException e )

        {

            e.printStackTrace( ) ;

            success = false ;

            throw e ;

        }

        finally

        {

            System.err.println( "SECURELY connect status  " + host + " with user name " + userName + " :" + ( success ? "SUCCESS" : "FAIL" ) ) ;

        }



        return success ;

    }



    public void close( )

    {

        if( this.sftpChannel != null )

        {

            this.sftpChannel.exit( ) ;

        }



        if( this.session != null )

        {

            this.session.disconnect( ) ;

        }

    }



    public boolean downloadFile( String remoteFile, String localFile )

    {

        try

        {

            this.sftpChannel.get( remoteFile, localFile ) ;



            return true ;

        }

        catch( Exception e )

        {

            e.printStackTrace( ) ;



            return false ;

        }

    }



    public boolean uploadFile( String localFile, String remoteFile )

    {

        try

        {

            this.sftpChannel.put( localFile, remoteFile ) ;



            return true ;

        }

        catch( Exception e )

        {

            e.printStackTrace( ) ;



            return false ;

        }

    }



    public boolean deleteFile( String remoteFile, int tryCount ) throws IOException

    {

        int count = 0 ;



        while( count++ < tryCount )

        {

            try

            {

                this.sftpChannel.rm( remoteFile ) ;



                return true ;

            }

            catch( Exception e )

            {

                System.err.println( "Trial " + count ) ;

                e.printStackTrace( ) ;

            }

        }



        return false ;

    }




Sharing Files Over Net wih Encryption ( RSA + AES )

We build a a tool for  "Sharing files over internet with encryption".

Here are simple principles that builds a secure system.
 

Program implements Something u know ,something u have pattern.

Something u know : Your pin, unless u do not share it with anybody

None of your previous data can be obtained by an intruder.

Something u have : Thumb, disk, usb,or mobile

Program never places an un-encrypted data to network or server.

So every encryption and decryption only occur on local environment.

Program stores files as chunks so a server intruder does now obtain full file. Files are stored at chunks.

Files are divided into blocks according to file size. Each block have different AES keys so decrypting a file needs multiple AES hacking.

Server does not hold enough  data for decrypting files. Files decrypts need RSA keys which are only found on Local ends.

Writing A Word Exporter for Primefaces Datatable

PDF and Excel Export are default features of primefaces datatables.
We need a doc exporter.


I saw some other posts doing this . My solution was a bit different for some restrictions(which i do not remember know :) )

Below is simple logic and necessary classes and some codes to give an idea.

Extend  org.primefaces.component.export.Exporter
Change necessary methods to add final texts to your doc generator.

import com.lowagie.text.BadElementException;

import com.lowagie.text.Document;

import com.lowagie.text.DocumentException;

import com.lowagie.text.Paragraph;

import com.lowagie.text.Table;

import com.lowagie.text.rtf.RtfWriter2;



public class DocExporter extends Exporter {



   protected Document              document;



   protected RtfWriter2            writer;



   protected Table                 doctable = null;







protected void addColumnValue(UIComponent component) throws DocumentException {

      // int cellIndex = row.getLastCellNum() == -1 ? 0 : row.getLastCellNum();

      // Cell cell = row.createCell(cellIndex);

      String value = component == null ? "" : exportValue(FacesContext.getCurrentInstance(), component);



      com.lowagie.text.Cell cell = new com.lowagie.text.Cell(value);

      cell.setBorderColor(new Color(255, 0, 0));

      // cell.setHeader(true);



      doctable.addCell(cell);



      // cell.setCellValue(new HSSFRichTextString(value));

   } 

***********************
At class extending LazyDataModel add a method as ExportDoc

public class TableModel<T> extends LazyDataModel<T> {





public void exportDoc(String reportName,boolean pageOnly) throws IOException {

      FacesContext context = FacesContext.getCurrentInstance();

      DocExporter exporter = new DocExporter();

      exporter.export(context, (DataTable) persistentUITable, reportName, pageOnly, false, "UTF-8", null, null);

      context.responseComplete();

   }

*****  Calling from JSF

<h:commandLink  action="#{tableModel.exportDoc( 'title' )}" >

                                            <p:graphicImage value="/images/exporter/word-logo.png" width="42" height="48"/> 

                                        </h:commandLink>

Parsing X12 Documents

X12 is a EDI standard for business transactions which is popular in North America.
(EDI is  sending  formatted data, by agreed message standards, from one system to another system )

Describing X12 or EDI is so long.
In this post I will just tell about how to write a simple X12 object for parsing data.
X12 lines  are just separated values so an object below will represent a common X12 segment.

For ones dealing with same things below will make sense.
*** This is just for giving idea.

public class X12Segment 

{



   public static final String NAME_ISA = "ISA" ;



    public static final String NAME_GS = "GS" ;

//................................  ALL TAGS YOU NEED


    // protected String segmentSeparator = "\n" ;



    // protected String fieldSeparator = "*" ;



    protected YX12Config config ;



    // X12SectionName|field1|field2|field3...|fieldn~

    protected String line ;



    protected String segmentName ;



    protected String[ ] fields ;



    public X12Segment( String line, YX12Config config )

    {

        this.config = config ;



        this.init( line ) ;

    }



    public void init( String line )

    {

        String strDelim = ( isBlankTrim( this.config.getSegmentDelimiter( ) ) ? this.config.getNewLineStr( ) : this.config.getSegmentDelimiter( ) ) ;



       



        this.line = line.trim( ).split( "\\" + strDelim, -2 )[ 0 ] ;



        final String[ ] tmp = this.line.split( "\\" + this.config.getFieldDelimiter( ), -2 ) ;



        this.segmentName = tmp[ 0 ] ;



        this.fields = tmp ;

    }



    public boolean checkType( String type )

    {

        return type.equals( this.getSegmentName( ) ) ;

    }



    public int getFieldCount( )

    {

        return this.fields.length - 1 ;

    }



    public String getField( int index )

    {

        return index >= this.fields.length ? null : this.fields[ index ] ;

    }



    public String[ ] getFields( )

    {

        return this.fields ;

    }



    public void setFields( String[ ] fields )

    {

        this.fields = fields ;

    }



    public String getSegmentName( )

    {

        return this.segmentName ;

    }



    public void setSegmentName( String segmentName )

    {

        this.segmentName = segmentName ;

    }



    public YX12Config getConfig( )

    {

        return this.config ;

    }



    public void setConfig( YX12Config config )

    {

        this.config = config ;

    }



    public String getLine( )

    {

        return this.line ;

    }



    public void setLine( String line )

    {

        this.line = line ;

    }



    public String toString( YX12Config config )

    {

        StringBuilder sb = new StringBuilder( this.segmentName ) ;



        for( int i = 1; i < this.fields.length; ++i )

        {

            sb.append( config.getFieldDelimiter( ) ) ;

            sb.append( this.fields[ i ] ) ;

        }



        return sb.toString( ) ;

    }



    @Override

    public String toString( )

    {

        return toString( this.config ) ;

    }

Punchout , OCI... B2B Marketing

Punchout is a distributed shopping model between buyer and suppliers.
A buyer user can login to a his system and transparently  navigates to supplier systems and make his shopping and when he returns his items are on Buyer cart.

Example : 
You login to your school system. Your school has a contract for computer company X. 
You click link go to website of X company. 
You X company website full featured . 
And when u are done click checkout(or whatever) to return to your system.


 Usually these processes go with cXML  cXML (commerce eXtensible Markup Language) 
 which provides  XML schemas for standard business transactions.

OCI is another implementation of Remote Shopping.

These standarts are great ,because they enable 2 companies to share catalogs with very simple
integrations.