CheckPointState (Storm 2.7.1 API)

java.lang.Object
- org.apache.storm.spout.CheckPointState

```
public class CheckPointState
extends Object
```
Captures the current state of the transaction in CheckpointSpout. The state transitions are as follows.
```
                  ROLLBACK(tx2)
               <-------------                  PREPARE(tx2)                     COMMIT(tx2)
 COMMITTED(tx1)-------------> PREPARING(tx2) --------------> COMMITTING(tx2) -----------------> COMMITTED (tx2)

 
```
During recovery, if a previous transaction is in PREPARING state, it is rolled back since all bolts in the topology might not have prepared (saved) the data for commit. If the previous transaction is in COMMITTING state, it is rolled forward (committed) since some bolts might have already committed the data.
During normal flow, the state transitions from PREPARING to COMMITTING to COMMITTED. In case of failures the prepare/commit operation is retried.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class CheckPointState.Action

static class CheckPointState.State

Constructor Summary

Constructors
Constructor Description

CheckPointState()

CheckPointState(long txid, CheckPointState.State state)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`equals(Object o)`
`CheckPointState.State`	`getState()`
`long`	`getTxid()`
`int`	`hashCode()`
`CheckPointState.Action`	`nextAction(boolean recovering)`	Get the next action to perform based on this checkpoint state.
`CheckPointState`	`nextState(boolean recovering)`	Get the next state based on this checkpoint state.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - CheckPointState
```
public CheckPointState(long txid,
                       CheckPointState.State state)
```
  - CheckPointState
```
public CheckPointState()
```
- Method Detail
  - getTxid
```
public long getTxid()
```
  - getState
```
public CheckPointState.State getState()
```
  - nextState
```
public CheckPointState nextState(boolean recovering)
```
    Get the next state based on this checkpoint state.
    
    Parameters:
    
    recovering - if in recovering phase
    
    Returns:
    
    the next checkpoint state based on this state.
  - nextAction
```
public CheckPointState.Action nextAction(boolean recovering)
```
    Get the next action to perform based on this checkpoint state.
    
    Parameters:
    
    recovering - if in recovering phase
    
    Returns:
    
    the next action to perform based on this state
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object