Alphabetically Sort a Java Collection based upon the 'toString' value of its member items

Question

Assume I have a user defined Java class called Foo such as:

public class Foo 
{

    private String aField;

    @Override
    public String toString()
    {         


        

Answer 1

public class Foo
   implements Comparable
{

    private String aField;

    public Foo(String s)
       {
       aField=s;
        }


    public String getAField()
        {
        return aField;
        }

   public int compareTo(Foo other)
        {
        return getAField().compareTo(other.getAField());
        }


    @Override
    public String toString()
    {
    return getAField();
    }

}

and then

Collections.sort(list);