regarding an Immutable class defensive copying
<p>I have a query regarding creating a Immutable class following are the points which I take in consideration..</p>

<ol>
<li>Make the class final </li>
<li>Make all members final, set them explicitly, in a static block, or in the constructor </li>
<li>Make all members private</li>
<li>No Methods that modify state</li>
<li>Be extremely careful to limit access to mutable member components(remember the field may be final but the object can still be mutable. ie private final Date imStillMutable) - See defensive copying or its cousin copy constructors for more info.</li>
</ol>

<p>But I did not understand the 5 point completely at all, could you please advise or show me a example in which the 5 point is clear in that example.</p>
