com.cloudera.livy.client.common

Class AbstractJobHandle<T>

java.lang.Object

com.cloudera.livy.client.common.AbstractJobHandle<T>

All Implemented Interfaces:

JobHandle<T>, Future<T>

@Private
public abstract class AbstractJobHandle<T>
extends Object
implements JobHandle<T>

Nested Class Summary

Nested classes/interfaces inherited from interface com.cloudera.livy.JobHandle

JobHandle.Listener<T>, JobHandle.State

Field Summary

Fields

Modifier and Type	Field and Description
protected List<JobHandle.Listener<T>>	listeners
protected JobHandle.State	state

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractJobHandle()

Method Summary

Modifier and Type	Method and Description
void	addListener(JobHandle.Listener<T> l)
boolean	changeState(JobHandle.State newState) Changes the state of this job handle, making sure that illegal state transitions are ignored.
protected abstract Throwable	error()
JobHandle.State	getState()
protected abstract T	result()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.concurrent.Future

cancel, get, get, isCancelled, isDone

Field Detail

listeners

protected final List<JobHandle.Listener<T>> listeners

state

protected volatile JobHandle.State state

Constructor Detail

AbstractJobHandle

protected AbstractJobHandle()

Method Detail

getState

public JobHandle.State getState()

Specified by:

getState in interface JobHandle<T>

addListener

public void addListener(JobHandle.Listener<T> l)

Specified by:

addListener in interface JobHandle<T>

changeState

public boolean changeState(JobHandle.State newState)

Changes the state of this job handle, making sure that illegal state transitions are ignored. Fires events appropriately. As a rule, state transitions can only occur if the current state is "higher" than the current state (i.e., has a higher ordinal number) and is not a "final" state. "Final" states are CANCELLED, FAILED and SUCCEEDED, defined here in the code as having an ordinal number higher than the CANCELLED enum constant.

result

protected abstract T result()

error

protected abstract Throwable error()