2.4. The Fqn Class
The previous section used the
Fqn class in its examples; now let's learn a bit more about that class.
A Fully Qualified Name (Fqn) encapsulates a list of names which represent a path to a particular location in the cache's tree structure. The elements in the list are typically
Strings but can be any Object or a mix of different types.
This path can be absolute (i.e., relative to the root node), or relative to any node in the cache. Reading the documentation on each API call that makes use of
Fqn will tell you whether the API expects a relative or absolute Fqn.
The
Fqn class provides are variety of factory methods; see the Javadoc for all the possibilities. The following illustrates the most commonly used approaches to creating an Fqn:
// Create an Fqn pointing to node 'Joe' under parent node 'Smith'
// under the 'people' section of the tree
// Parse it from a String
Fqn abc = Fqn.fromString("/people/Smith/Joe/");
// Here we want to use types other than String
Fqn acctFqn = Fqn.fromElements("accounts", "NY", new Integer(12345));
Note that
Fqn f = Fqn.fromElements("a", "b", "c");
is the same as
Fqn f = Fqn.fromString("/a/b/c");