unchecked or unsafe error

code]private static void constructCodeTable(BinaryTreeNode btn,Stack st,Hashtable codeTable)

{

if(btn!=null)

{

if(btn instanceof LeafNode)

{

codeTable.put(((InternalNode)btn).getKey(),st);

}

else

{

st.push(new Integer(0));

constructCodeTable(((InternalNode)btn).getLeftChild(),st,codeTable);

st.pop();

st.push(new Integer(1));

constructCodeTable(((InternalNode)btn).getRightChild(),st,codeTable);

st.pop();

}

}

}

[/code]

InternalNode.java and LeafNode.java extends BInaryNode.java

InternalNode has function getLeftChild() and getRightChild()

LeafNode.java has function getKey();

when compiled , getting error:

Note: uses unchecked or unsafe operations.

Note: Recompile with -Xlint:unchecked for details..

can anyone tell why?

[888 byte] By [eternalwila] at [2007-10-2 17:45:11]