java.lang.Object

org.elasticsearch.common.component.Lifecycle

public class Lifecycle
extends java.lang.Object

Lifecycle state. Allows the following transitions:

INITIALIZED -> STARTED, STOPPED, CLOSED
STARTED -> STOPPED
STOPPED -> STARTED, CLOSED
CLOSED ->

Also allows to stay in the same state. For example, when calling stop on a component, the following logic can be applied:

 public void stop() {
  if (!lifecycleState.moveToStopped()) {
      return;
  }
 // continue with stop logic
 }

NOTE: The Lifecycle class is thread-safe. It is also possible to prevent concurrent state transitions by locking on the Lifecycle object itself. This is typically useful when chaining multiple transitions.

Note, closed is only allowed to be called when stopped, so make sure to stop the component first. Here is how the logic can be applied. A lock of the lifecycleState object is taken so that another thread cannot move the state from STOPPED to STARTED before it has moved to CLOSED.

 public void close() {
  synchronized (lifecycleState) {
      if (lifecycleState.started()) {
          stop();
      }
      if (!lifecycleState.moveToClosed()) {
          return;
      }
  }
  // perform close logic here
 }

Nested Class Summary

Nested Classes

Modifier and Type Class Description

static class Lifecycle.State
Constructor Summary

Constructors

Constructor Description

Lifecycle()

Method Summary

Modifier and Type	Method	Description
`boolean`	`canMoveToClosed()`
`boolean`	`canMoveToStarted()`
`boolean`	`canMoveToStopped()`
`boolean`	`closed()`	Returns `true` if the state is closed.
`boolean`	`initialized()`	Returns `true` if the state is initialized.
`boolean`	`moveToClosed()`
`boolean`	`moveToStarted()`
`boolean`	`moveToStopped()`
`boolean`	`started()`	Returns `true` if the state is started.
`Lifecycle.State`	`state()`
`boolean`	`stopped()`	Returns `true` if the state is stopped.
`boolean`	`stoppedOrClosed()`
`java.lang.String`	`toString()`

Methods inherited from class java.lang.Object

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

Constructor Details
- Lifecycle
  
  public Lifecycle()
Method Details
- state
  
  public Lifecycle.State state()
- initialized
  
  public boolean initialized()
  
  Returns true if the state is initialized.
- started
  
  public boolean started()
  
  Returns true if the state is started.
- stopped
  
  public boolean stopped()
  
  Returns true if the state is stopped.
- closed
  
  public boolean closed()
  
  Returns true if the state is closed.
- stoppedOrClosed
  
  public boolean stoppedOrClosed()
- canMoveToStarted
  
  public boolean canMoveToStarted() throws java.lang.IllegalStateException
  
  Throws:
  
  java.lang.IllegalStateException
- moveToStarted
  
  public boolean moveToStarted() throws java.lang.IllegalStateException
  
  Throws:
  
  java.lang.IllegalStateException
- canMoveToStopped
  
  public boolean canMoveToStopped() throws java.lang.IllegalStateException
  
  Throws:
  
  java.lang.IllegalStateException
- moveToStopped
  
  public boolean moveToStopped() throws java.lang.IllegalStateException
  
  Throws:
  
  java.lang.IllegalStateException
- canMoveToClosed
  
  public boolean canMoveToClosed() throws java.lang.IllegalStateException
  
  Throws:
  
  java.lang.IllegalStateException
- moveToClosed
  
  public boolean moveToClosed() throws java.lang.IllegalStateException
  
  Throws:
  
  java.lang.IllegalStateException
- toString
  
  public java.lang.String toString()
  
  Overrides:
  
  toString in class java.lang.Object

Class Lifecycle

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Details

Method Details