org.apache.flink.runtime.state

Interface StateHandle<T>

All Superinterfaces:

AutoCloseable, Closeable, Serializable, StateObject

All Known Subinterfaces:

StreamStateHandle

All Known Implementing Classes:

AsynchronousStateHandle, ByteStreamStateHandle, FileSerializableStateHandle, FileStreamStateHandle, LocalStateHandle, SerializedStateHandle

public interface StateHandle<T>
extends StateObject

StateHandle is a general handle interface meant to abstract operator state fetching. A StateHandle implementation can for example include the state itself in cases where the state is lightweight or fetching it lazily from some external storage when the state is too large.

Method Summary

Modifier and Type	Method and Description
T	getState(ClassLoader userCodeClassLoader) This retrieves and return the state represented by the handle.

Methods inherited from interface org.apache.flink.runtime.state.StateObject

discardState, getStateSize

Methods inherited from interface java.io.Closeable

close

Method Detail

getState

T getState(ClassLoader userCodeClassLoader)
    throws Exception

This retrieves and return the state represented by the handle.

Parameters:

userCodeClassLoader - Class loader for deserializing user code specific classes

Returns:

The state represented by the handle.

Throws:

Exception - Thrown, if the state cannot be fetched.