hash map error

[Puneet N Vyas]

why the following code,which contains hashmap even after being populated with keys/values contains null,that is patternAsso hashmap contains null value,can any one tell why it happened.
thanks for support

   
 
import java.lang.*;
import java.util.*;
import java.io.*;
import java.util.regex.*;
//move to line 288 in after opening this file in Jcreator
public class hash
{
public static void main(String args[])
{

Vector Candidate2=new Vector();//for holding candidate patterns of length 2
Vector Candidate3=new Vector();//for holding candidate patterns of length 3
 Map <String,Integer> CandidateSeq1 = new HashMap<String,Integer>(); 
   Map <String,String> patternasso = new HashMap<String,String>(); 
   Map <String,String> patternAsso= new HashMap<String,String>(); 
 String items[] = {"a","b","c","d","e","f"};
  Vector pattern_Strings=new Vector();
 Vector patternStrings3=new Vector();//for storing pattern strings of size 3
   //for pattern strings regular expression,for patterns oflength 2
 String p1[]={"a.* ","b.* ","c.* ","d.* ","e.* ","f.* "};
 String p2[]={".*a",".*b",".*c",".*d",".*e",".*f"};
 
   String op[]=new String[p1.length*p1.length];
  
   for(int ii=0, kk=0;ii<p1.length;ii++)
   {
   for(int jj=0;jj<p1.length;jj++,kk++)
   {
   op[kk]=p1[ii]+p2[jj];
   pattern_Strings.add(op[kk]); //adding to vector pattern_Strings patterns as a.* .*a
   }
   }
 

 

 
 //regular expression pattern strings for pattern of length 3
 for(int hh=0;hh<p1.length;hh++)
 {
 for(int mm=0;mm<items.length;mm++)
 {
 for(int nn=0;nn<items.length;nn++)
 {
 
 patternStrings3.add(p1[hh]+items[mm]+items[nn]);
 //filew.write((String)p1[hh]+items[mm]+items[nn]);
// System.out.println(p1[hh]+items[mm]+items[nn]);
 }
 }
 
 }
 

 
 //storing patterns of length 3
/*
 for(int hh=0;hh<items.length;hh++)
 {
 for(int mm=0;mm<items.length;mm++)
 {
 for(int nn=0;nn<items.length;nn++)
 {
 
 patternStrings3.add(p1[hh]+items[mm]+items[nn]);
 filew.write((String)p1[hh]+items[mm]+items[nn]);
 System.out.println(p1[hh]+items[mm]+items[nn]);
 }
 }
 
 }*/
 

 

 

 
 
 
 
 //adding candiates if form a a,a b etc
 //adding patten strings of form aa,ab ,ac ,etc...
 for(int i=0,k=0; i<items.length; i++)
{
for(int j=0;j<items.length;j++,k++)
{
 
Candidate2.add(items[i]+" "+items[j]);
pattern_Strings.add(items[i]+items[j]);
}
 
}
 
 for(int i=0,k=0; i<items.length; i++)
{
for(int j=0;j<items.length;j++,k++)
{
Candidate2.add(items[i]+items[j]);
}
}
 

 System.out.println("minimum support threshold is : 2");
 
 int len1=Candidate2.size();
 
/*displaying candidate patterns
     System.out.println("candidate patterns are");
       System.out.println("size of candidate patterns are:"+Candidate2.size());
      for (int ii = 0; ii < Candidate2.size() ; ++ii) 
      {
      System.out.println((String)Candidate2.get(ii));
      }
      
  */   
     
     
     
int support2[]=new int[Candidate2.size()];
for(int su=0;su<support2.length;su++)
{
support2[su]=0;
}
 
 
  //  System.out.println("pattern strings are:");
  /*  Enumeration e1=pattern_Strings.elements();
        while(e1.hasMoreElements())
   {
  
   String patternStr=(String)e1.nextElement();
   System.out.println(patternStr);
   //pattenasso.put(patternStr,)
  
 
   }*/
    //for(pattern_Strings)
    
  
 
  
  
  
   //generating length 3 candidate sequential patterns
  
  for(int ii=0,kk=0; ii<6; ii++)
{
for(int jj=0;jj<6;jj++,kk++)
{
 
 for(int ll=0;ll<6;kk++,ll++)
 {
//Candiate3.add(a[i]+" "+a[j]+);
 //Candidate3.add(items[ii]+" "+items[jj]+items[ll]);
 //Candidate3.add(items[ii]+items[jj]+" "+items[ll]);
 //Candidate3.add(items[ii]+items[jj]+items[ll]);
// Candidate3.add(items[ii]+" "+items[jj]+" "+" "+items[ll]);
  Candidate3.add(items[ii]+" "+items[jj]+items[ll]);
// System.out.println(items[ii]+" "+items[jj]+items[ll]);
 }
    
    }
    
   }
  
       
int support3[]=new int[Candidate3.size()];
for(int su=0;su<support3.length;su++)
{
support3[su]=0;
}
 
 //wrtiting candidates of length 3 onto file
 try
 {
FileWriter file1 = new FileWriter("C:\\can4.txt",false);
for (int i = 0; i < len1; ++i) 
{
  
  String s1=(String)Candidate3.get(i);
   file1.write (s1);
  // System.out.println(s1);
 int ij=  Candidate3.indexOf(s1);
  //System.out.println(ij);
   file1.write ("\t");
   file1.write ("\n");
}
file1.close();
 
 
 }catch(FileNotFoundException e)
 {
e.printStackTrace();
}
 catch (IOException e) 
 {
e.printStackTrace();
}
 
 
 
 
 
 
 
 
 
 

 
 
 
 
  
  
System.out.println("length of Candidate 3sequential pattern vector:"+Candidate3.size());
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
//why this hashmap contains null,even after bening populated with keys/values  
  
  //Storing pattern strings  in patternasso hash map,pattern strings=key,patterns= values
  for(int i1=0;i1<pattern_Strings.size();i1++)
    {
   // pattenasso.put((String)pattern_Strings.get(i1),(String)Candidate2.get(i1));
  // System.out.println(pattern_Strings.get(i1)+":"+Candidate2.get(i1));
 String s1=( String)pattern_Strings.get(i1);
 String s2=( String)Candidate2.get(i1);
  patternasso.put(s1,s2) ;
 
  
    }
 
   //this prints null
    System.out.println("a.* .*a"+  patternasso.get("a.* .*a"));
  
  
  
  
   //for storing pattern strings in patternAsso hash map,pattern strings=key,patterns= values
  //stores key :values    of form "a.*aa":"a aa"
     //why the hashmap contains the null,even after populating the hashmap
     
     
      for(int ii1=0;ii1<Candidate3.size();ii1++)
    {
   
 String s1=( String)patternStrings3.get(ii1);
 String s2=( String)Candidate3.get(ii1);
  
  patternAsso.put(s1,s2) ;
      System.out.println(s1+" " +s2);
  
    }
       System.out.println("key a.*aa value is"+ patternAsso.get("a.*aa")); 
    
    
    
    
    
//iterating through the pattenasso Map to see patten strings:strings,for pattern of length 3
Iterator iterator5= patternAsso.keySet().iterator();
   while (iterator5.hasNext())
    {
   Object key1 = iterator5.next();
   Object value1 = patternAsso.get(key1);
   String key=(String) key1;
   String value=(String)value1;
   
 //checking pattenasso map,does it have correct enties;
 // System.out.println(key+value);
 } 
    
    
    
 
    
    
    
    
    
 
   
  //printing pattern Strings
 //  System.out.println("total number of pattern strings are="+pattern_Strings.size());
 

 

 

 // System.out.println("String patterns:Strings");
//iterating through the pattenasso Map to see patten strings:strings for length 2 patterns
Iterator iterator= patternasso.keySet().iterator();
   while (iterator.hasNext())
    {
   Object key1 = iterator.next();
   Object value1 =  patternasso.get(key1);
   String key=(String) key1;
   String value=(String)value1;
   
 //checking pattenasso map,does it have correct enties;
 // System.out.println(key+value);
 } 
   
   
   
   
   
   Matcher m1[];
//declare as many matcher objects  as  regular expressions are
   
   
     
     
     
try 
{

        File f1 = new File("C:\\sample.txt");
FileReader fr1 = new FileReader(f1);
BufferedReader br1 = new BufferedReader(fr1);
LineNumberReader lnr1 = new LineNumberReader(br1);
String line1;

System.out.println("Sequence database");;
System.out.println("itemset itemset ......");;
while ((line1 = br1.readLine()) != null) 
{
 

System.out.println(line1);
 
String t=line1;
 
 CharSequence inputStr = t;//stroing input sequences
//testing for length 3 patterns
 /*String patternStr1= "a.*ab";
    Pattern pattern2 = Pattern.compile(patternStr1);
    Matcher matcher2 = pattern2.matcher(inputStr);
    boolean matchFound2 = matcher2.find();
    //System.out.println("ab c");
if(matchFound2)
{
System.out.println("a ab");
}*/
 
 Enumeration e1=pattern_Strings.elements();
     while(e1.hasMoreElements())
   {
     //
   String patternStr=(String)e1.nextElement();
   Pattern pattern = Pattern.compile(patternStr);
   Matcher matcher = pattern.matcher(inputStr);
   boolean matchFound = matcher.find();
//   System.out.println(patternStr);
   //pattenasso.put(patternStr,)
   if(matchFound)
   {
 int i= pattern_Strings.indexOf(patternStr)  ;
   String v=( String)patternasso.get(patternStr);
   support2[i]++;
   CandidateSeq1.put(v,support2[i]);
   
   }
  
 
   }
    
    
    /*
     String patternStr= "a.* .*a";
     
 Pattern pattern1 = Pattern.compile(patternStr);
     Matcher matcher1 = pattern1.matcher(inputStr);
     boolean matchFound1 = matcher1.find();
  if(matchFound1)
    {
 
++support2[0];
 
 CandidateSeq1.put("a a",support2[0]);
    }
   
     String patternStr1= "b.* .*b";
    Pattern pattern2 = Pattern.compile(patternStr1);
    Matcher matcher2 = pattern2.matcher(inputStr);
    boolean matchFound2 = matcher2.find();
     
     if(matchFound2)
    {
 
//candidateSeq1.remove("b b");
++support2[1];
CandidateSeq1.put("b b",support2[1]);
 
    }
 
    String patternStr2= "ab";
    Pattern pattern3 = Pattern.compile(patternStr2);
    Matcher matcher3 = pattern3.matcher(inputStr);
    boolean matchFound3 = matcher3.find();
     
     if(matchFound3)
    {
 
//candidateSeq1.remove("b b");
++support2[2];
CandidateSeq1.put("ab",support2[2]);
 
    }*/
 

 

 

}//end of while loop
 
//displaying sequences of length 2
 
Iterator iterator2 = CandidateSeq1.keySet().iterator();
System.out.println("length 2 sequential pattern is" +"Sequential pattern"+":"+"Support_count");
while (iterator2.hasNext()) {
   Object key1 = iterator2.next();
   Object value1 = CandidateSeq1.get(key1);
   String key=(String) key1;
   Integer value=(Integer)value1;
    int val=value.intValue();
 //  System.out.println(val);
  // System.out.println(key);
  if(val>=2)
  {
  
   System.out.println("<"+key+">"+":" + val);
   }
    
}
 
     }//end of try block
 
catch (FileNotFoundException e)
 {
e.printStackTrace();
}
 catch (IOException e) 
 {
e.printStackTrace();
}
 

 

 

 

}


}