Cannot be instantiated error

[champion]

I am the following when i try to run my java program. I have included the code below

CollectionExamp le1.java java.util.Colle ction is abstract; cannot be instatiated
Collection col=new Collection();

CODE

import java.util.*;

class CollectionsExample1
{

static void CollectionMethod()

{
  Collection col=new Collection();
  
  col.add("J");
  col.add("e");
  col.add("s");
  col.add("u");
  col.add("s");

  boolean cc=col.contains("g");
  System.out.println("\n");
  System.out.println(cc);
  System.out.println("\n");

  col.remove("u");
  System.out.println("u has been removed");
  System.out.println("\n");

  Iterator gh=col.iterator();
  while(gh.hasNext())
   {
    Object element=gh.next();
    System.out.println(element);
   }
}



static void SetsMethod()
{    

    // Create the set
    Set set = new HashSet();
    
    // Add elements to the set
    set.add("L");
    set.add("O");
    set.add("R");
    set.add("D");
    set.add("D");    


    // Get number of elements in set
    int size = set.size();         
    System.out.println("The size of the Set is "+size);    


    //Adding an element that already exists in the set has no effect
    System.out.println("Adding O has no effect on size of the set");
    set.add("O");
    size = set.size(); 
    System.out.println("The size of the Set is "+size);    
             
    
    // Determining if an element is in the set
    boolean b = set.contains("L");  
    System.out.println(b);

    b = set.contains("c");          
    System.out.println(b);
    
    // Iterating over the elements in the set
    Iterator it = set.iterator();
    while (it.hasNext()) 
    {
        // Get element
        Object element = it.next();
	System.out.println(element);
    }
    
    // Remove elements from the set
    set.remove("D");

    // Create an array containing the elements in the set (in this case a String array)
    String[] array = (String[])set.toArray(new String[set.size()]);

    for(int i=0;i<set.size();i++)
      System.out.println(array[i]);

}


static void ArrayListMethod()
{
    

   // Create the sorted set
    SortedSet set = new TreeSet();
    
    // Add elements to the set
    set.add("b");
    set.add("c");
    set.add("a");
    set.add("z");
    set.add("a");    

    // Iterating over the elements in the set
    Iterator it = set.iterator();
    while (it.hasNext()) 
    {
        // Get element
        Object element = it.next();
	System.out.println(element);
    }
    // The elements are iterated in order: a, b, c
    
    // Create an array containing the elements in a set (in this case a String array).
    // The elements in the array are in order.
    String[] array = (String[])set.toArray(new String[set.size()]);
    
    System.out.println("\n\n");


    for(int i=0;i<set.size();i++)
      System.out.println(array[i]);

}

public static void main(String [] args)
  {
    SetsMethod();
    ArrayListMethod();
    CollectionMethod();
  } 

}

[horace1]

Collection is an interface so you cannot create an object

static void CollectionMethod()
{
  Collection col=new Collection();

you need to use something that implements it, e.g.

  Vector col=new Vector();

[Ganon11]

You can also write

Collection col = new Vector();

or any other Collection-extending class like List, Set, Tree, etc. in place of the class name on the right. In this case, though, you can only use the methods that all Collections have.