Logical error in creating a HashMap

[Anil Giri]

I am trying to create a HashMap which string keys and HashSet of Strings as values. I wrote the following code for this.

 
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.*;

class CVT {

	Map <String,HashSet<String>> cvtmap=new HashMap<String,HashSet<String>>();
	
	void populateCVT(String CVTFile) {
		 
		String tmpKey;
		HashSet<String> tmpValueSet=new HashSet<String>();
		try{
			    FileInputStream fstream = new FileInputStream(CVTFile);
			    DataInputStream in = new DataInputStream(fstream);
			    BufferedReader br = new BufferedReader(new InputStreamReader(in));
			    String strLine;
			    //Read File Line By Line
			    while ((strLine = br.readLine()) != null)   {
				    String[] broken=strLine.split(",");
			    	tmpKey=broken[0];
			    	tmpValueSet.clear();
			    	for( int i=1;i<broken.length;i++ )
			    	  		tmpValueSet.add(broken[i]);
			    	cvtmap.put(tmpKey,tmpValueSet);
			   	}
			    in.close(); //Close the input stream
			    }catch (Exception e){//Catch exception if any
			      System.err.println("Error: " + e.getMessage());
			    }
		}

	
	void printCVT( ) {
	    Set<String> valueSet=new HashSet<String>();
		Set<Map.Entry<String,HashSet<String>>> keyValueSet= cvtmap.entrySet();
		for(Map.Entry<String,HashSet<String>> looper : keyValueSet){
			System.out.print(looper.getKey()+" : ");
			valueSet=looper.getValue();
			for(String valueLooper : valueSet)
				System.out.print(valueLooper+" ");
			System.out.println();
		}
	}
}


public class Testing {
	public static void main(String[] args) {
		
		CVT cvt=new CVT();
		cvt.populateCVT("D:\\Code\\cvtfile.txt");
		cvt.printCVT();
	}
} 

The file cvtfile.txt has the following content:

  
AKey,a1,a2,a3,a4
BKey,b1,b2,b3
CKey,c1,c2,c2,c3,c4
DKey, d1,d2
DKey,d1,d2,d3,d4,d5  

The Output is:

DKey : d1 d2 d3 d4 d5 
BKey : d1 d2 d3 d4 d5 
AKey : d1 d2 d3 d4 d5 
CKey : d1 d2 d3 d4 d5     

I am not able to make out why is the value set that is read at last is getting mapped to all the keys.
I would be grateful for any comments/suggestions.

[Anil Giri]

[Ireneusz Kordal]

Hi,

error is in line line 25, change this line into:

  tmpValueSet=new HashSet<String>();   

[Anil Giri]

Thanks sir!
That corrected it.

So that means the put method of the HashMap class does not copy the object to the map. It just links the object to the map value, so that the last value added the object persists.

[Ireneusz Kordal]

So that means the put method of the HashMap class does not copy the object to the map.

Yes, it does not copy the object (the content of the object), it only stores the reference to the object.