Retrieve array inside a list as a Map value

Hi All,

I am trying to retrieve data from a map value. One of the map value is actually an array inside a list. I am able to get only the memory location rather than the values inside the array inside the list. Below is the code that I am working on. Can someone please help me

Code:

---

import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.commons.collections.*;
import org.apache.commons.collections.collection.*;
import org.apache.commons.collections.MultiMap;
import org.apache.commons.collections.MultiHashMap;
import org.apache.commons.collections.map.*;

public class Names {
        public static void main(String args[])
        {
    List result = new LinkedList();
   
    String[] vs= {"name1","name2"};
       
    result.add(vs);
   
        MultiMap map = new MultiHashMap( );
        map.put("ONE","TEST");       
        map.put("ONE",1);
        map.put("ONE", result);
       
        /*Set set = map.entrySet();
    Iterator it = set.iterator();
    while (it.hasNext()) {
      Map.Entry entry = (Map.Entry) it.next();
      System.out.println(entry.getKey() + " : " + entry.getValue());
    }*/

       
        Set keySet = map.keySet( );
        Iterator keyIterator = keySet.iterator();       
        while( keyIterator.hasNext( ) ) {
            Object key = keyIterator.next( );
            System.out.println( "Key: " + key);
           
            Collection values = (Collection) map.get( key );
         
                    Iterator valuesIterator = values.iterator( );
                    while( valuesIterator.hasNext( ) ) {
                           
                        System.out.println( "Value: " + valuesIterator.next( ));
                       
                    }
          }           
           
        }

}

---

The output that I get is

Code:

---

Key: ONE
Value: TEST
Value: 1
Value: [[Ljava.lang.String;@9304b1]

---

Output Expected

Code:

---

Key: ONE
Value: TEST
Value: 1
Value: name1
Value: name2

---

Thanks

Quote:

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Value: [[Ljava.lang.String;@9304b1]

---

\
This is what the default toString() method returns for an object without its own toString() method.
It says: [ = an array, L =~ List of String(??)

I think The value of ONE is an array which doesn't have a toString() method, so you get the default toString() output. You might need to extend the class that the array is in and add a toString() method to return its contents vs getting the default value.

Your various changes of definitions loses the id of the contents. Here's how to get what't there:

Code:

---

/*
I am trying to retrieve data from a map value. One of the map value is actually an array inside a list.
I am able to get only the memory location rather than the values inside the array inside the list.
Below is the code that I am working on. Can someone please help me

The output that I get is

Key: ONE
Value: TEST
Value: 1
Value: [[Ljava.lang.String;@9304b1]

Output Expected
Key: ONE
Value: TEST
Value: 1
Value: name1
Value: name2

*/

import java.util.*;


public class ToStringProblem {

        public static void main(String args[])          {
      List result = new LinkedList();
   
      String[] vs= {"name1","name2"};
       
      result.add(vs);
   
          HashMap map = new HashMap( );
          map.put("ONE", result);
       
          Set keySet = map.keySet( );
          Iterator keyIterator = keySet.iterator();       

          while( keyIterator.hasNext( ) ) {
              Object key = keyIterator.next( );
              System.out.println( "Key: " + key);
             
              Collection values = (Collection) map.get( key );
             
                Iterator valuesIterator = values.iterator( );
                while( valuesIterator.hasNext( ) ) {
                        Object obj = valuesIterator.next();
            String[] sArray = (String[]) obj;
                  System.out.println( "Value: " + obj
                                + ", array=" + Arrays.toString(sArray));
            // Key: ONE
            // Value: [Ljava.lang.String;@19821f, array=[name1, name2]
                   
                }
      } // end while()           
           
  }

}

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Hi Ms.Ranjan,
Please check the modified code to print according to your requirement

import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.commons.collections.*;
import org.apache.commons.collections.collection.*;
import org.apache.commons.collections.MultiMap;
import org.apache.commons.collections.MultiHashMap;
import org.apache.commons.collections.map.*;

public class Names {
public static void main(String args[])
{
List result = new LinkedList();

String[] vs= {"name1","name2"};

result.add(vs);

MultiMap map = new MultiHashMap( );
map.put("ONE","TEST");
map.put("ONE",1);
map.put("ONE", result);

/*Set set = map.entrySet();
Iterator it = set.iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
System.out.println(entry.getKey() + " : " + entry.getValue());
}*/


Set keySet = map.keySet( );
Iterator keyIterator = keySet.iterator();
while( keyIterator.hasNext( ) ) {
Object key = keyIterator.next( );
System.out.println( "Key: " + key);

Collection values = (Collection) map.get( key );

Iterator valuesIterator = values.iterator( );
while( valuesIterator.hasNext( ) ) {
Object obj=valuesIterator.next( );
if(obj instanceof LinkedList){
LinkedList list=(LinkedList)obj;
String[] x=(String[])list.get(0);
System.out.print( "Value: ");
for(int i=0;i<x.length;i++)
System.out.print( x[i]+" ");
}
else
System.out.println( "Value: " + obj);
}
}

}

}