Database Reference
In-Depth Information
Path Created: CuratorEventImpl{
type=CREATE,
resultCode=0,
path='/a/test/path',
name='/a/test/path',
children=null,
context=null,
stat=null,
data=null,
watchedEvent=null,
aclList=null
}
To create paths with different modes, use the
withMode
method in the
create
command. For example, a queuing system might want to create
znode
s that are both persistent and sequential:
client.create()
.withMode(CreateMode.
PERSISTENT_SEQUENTIAL
)
.forPath("/queue/job")
;
Valid modes are
PERSISTENT
,
EPHEMERAL
,
PERSISTENT_SEQUENTIAL
,
and
EPHEMERAL_SEQUENTIAL
. The mode can also be determined using
the
CreateMode .fromFlag
method, which converts the flags used by
the native ZooKeeper client to the appropriate
CreateMode
option as
demonstrated in the
wiley.streaming .curator.ModeTest
example.
The
checkExists
command has two uses. First, whether or not the
command returns
null
allows for the existence check implied by its name.
If the path given exists, a
Stat
object is returned with a variety of useful
information about the path. This includes the number of children the path
has, the version number, and the creation and modification times.
The data element or children of a
znode
are retrieved using the
getData
and
getChildren
commands, respectively. Like the
create
command,
they can be executed in the background and always end with a
forPath
method. Unlike
create
, they do not take an optional byte array in their
path.