T
- type of the retrievable object which is stored under the wrapped stream handlepublic class RetrievableStreamStateHandle<T extends Serializable> extends Object implements StreamStateHandle, RetrievableStateHandle<T>, Closeable
StreamStateHandle
to make the referenced state object retrievable trough a simple get call.
This implementation expects that the object was serialized through default serialization of Java's
ObjectOutputStream
.Constructor and Description |
---|
RetrievableStreamStateHandle(Path filePath,
long stateSize) |
RetrievableStreamStateHandle(StreamStateHandle streamStateHandle) |
Modifier and Type | Method and Description |
---|---|
void |
close() |
void |
discardState()
Discards the state referred to by this handle, to free up resources in
the persistent storage.
|
long |
getStateSize()
Returns the size of the state in bytes.
|
FSDataInputStream |
openInputStream()
Returns an
FSDataInputStream that can be used to read back the data that
was previously written to the stream. |
T |
retrieveState()
Retrieves the object that was previously written to state.
|
public RetrievableStreamStateHandle(StreamStateHandle streamStateHandle)
public RetrievableStreamStateHandle(Path filePath, long stateSize)
public T retrieveState() throws Exception
RetrievableStateHandle
retrieveState
in interface RetrievableStateHandle<T extends Serializable>
Exception
public FSDataInputStream openInputStream() throws IOException
StreamStateHandle
FSDataInputStream
that can be used to read back the data that
was previously written to the stream.openInputStream
in interface StreamStateHandle
IOException
public void discardState() throws Exception
StateObject
discardState
in interface StateObject
Exception
public long getStateSize()
StateObject
If the the size is not known, return 0
.
getStateSize
in interface StateObject
public void close() throws IOException
close
in interface Closeable
close
in interface AutoCloseable
IOException
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