Database Reference
In-Depth Information
When used immediately, the
getData
command returns a byte array,
which can be deserialized into whatever format the application desires. For
example,ifthedatawereasimpletextstring,itcanbesetandthenretrieved
as follows (assuming the
znode
already exists):
client.setData()
.forPath("test/string", "A Test String".getBytes());
System.
out
.println(
new
String(
client.getData()
.forPath("test/string")
)
);
Like the create command,
getData
can be executed in the background. In
the background case, the
forPath
method returns
null
and the data is
returned in the background callback. For example, the same code as the
previous example implemented as a background callback would look like
this:
client.getData().inBackground(
new
BackgroundCallback()
{
public void
processResult(CuratorFramework arg0,
CuratorEvent arg1)
throws
Exception {
System.
out
.println(
new
String(arg1.getData()));
}
}).forPath("test/string");
The
previous
two
examples
are
implemented
in
wiley.streaming.curator .DataTest
.
The
getChildren
command works essentially the same way as the
getData
command. Instead of returning a byte array, this command
returns a list of
String
objects giving the names of the child
znode
s of the
parent object. This example shows this command in action by first adding
several jobs to an imaginary queue
znode
and then calling
getChildren
on the node to retrieve the list of children, as demonstrated in
wiley.streaming.curator.QueueTest
:
