ForeignExceptionDispatcher (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher

All Implemented Interfaces:

ForeignExceptionListener, ForeignExceptionSnare
```
@InterfaceAudience.Private
public class ForeignExceptionDispatcher
extends Object
implements ForeignExceptionListener, ForeignExceptionSnare
```
The dispatcher acts as the state holding entity for foreign error handling. The first exception received by the dispatcher get passed directly to the listeners. Subsequent exceptions are dropped.
If there are multiple dispatchers that are all in the same foreign exception monitoring group, ideally all these monitors are "peers" -- any error on one dispatcher should get propagated to all others (via rpc, or some other mechanism). Due to racing error conditions the exact reason for failure may be different on different peers, but the fact that they are in error state should eventually hold on all.
This is thread-safe and must be because this is expected to be used to propagate exceptions from foreign threads.

Field Summary

Fields
Modifier and Type Field and Description

protected List<ForeignExceptionListener> listeners

protected String name

Fields
Modifier and Type	Field and Description
`protected List<ForeignExceptionListener>`	`listeners`
`protected String`	`name`

Constructor Summary

Constructors
Constructor and Description

ForeignExceptionDispatcher()

ForeignExceptionDispatcher(String name)

Constructors
Constructor and Description
`ForeignExceptionDispatcher()`
`ForeignExceptionDispatcher(String name)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addListener(ForeignExceptionListener errorable)` Listen for failures to a given process.
`ForeignException`	`getException()` Get the value of the captured exception.
`String`	`getName()`
`boolean`	`hasException()` Non-exceptional form of `ForeignExceptionSnare.rethrowException()`.
`void`	`receive(ForeignException e)` Receive a ForeignException.
`void`	`rethrowException()` Rethrow an exception currently held by the `ForeignExceptionSnare`.

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

- Field Detail
  - name
```
protected final String name
```
  - listeners
```
protected final List<ForeignExceptionListener> listeners
```
- Constructor Detail
  - ForeignExceptionDispatcher
```
public ForeignExceptionDispatcher(String name)
```
  - ForeignExceptionDispatcher
```
public ForeignExceptionDispatcher()
```
- Method Detail
  - getName
```
public String getName()
```
  - receive
```
public void receive(ForeignException e)
```
    Description copied from interface: ForeignExceptionListener
    
    Receive a ForeignException.
    Implementers must ensure that this method is thread-safe.
    
    Specified by:
    
    receive in interface ForeignExceptionListener
    
    Parameters:
    e - exception causing the error. Implementations must accept and handle null here.
  - rethrowException
```
public void rethrowException()
                      throws ForeignException
```
    Description copied from interface: ForeignExceptionSnare
    
    Rethrow an exception currently held by the ForeignExceptionSnare. If there is no exception this is a no-op
    
    Specified by:
    
    rethrowException in interface ForeignExceptionSnare
    
    Throws:
    
    ForeignException - all exceptions from remote sources are procedure exceptions
  - hasException
```
public boolean hasException()
```
    Description copied from interface: ForeignExceptionSnare
    
    Non-exceptional form of ForeignExceptionSnare.rethrowException(). Checks to see if any process to which the exception checkers is bound has created an error that would cause a failure.
    
    Specified by:
    
    hasException in interface ForeignExceptionSnare
    
    Returns:
    true if there has been an error,false otherwise
  - getException
```
public ForeignException getException()
```
    Description copied from interface: ForeignExceptionSnare
    
    Get the value of the captured exception.
    
    Specified by:
    
    getException in interface ForeignExceptionSnare
    
    Returns:
    the captured foreign exception or null if no exception captured.
  - addListener
```
public void addListener(ForeignExceptionListener errorable)
```
    Listen for failures to a given process. This method should only be used during initialization and not added to after exceptions are accepted.
    
    Parameters:
    errorable - listener for the errors. may be null.

Class ForeignExceptionDispatcher

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

name

listeners

Constructor Detail

ForeignExceptionDispatcher

ForeignExceptionDispatcher

Method Detail

getName

receive

rethrowException

hasException

getException

addListener