Package org.springframework.webflow.execution.repository

Interface FlowExecutionRepository

All Known Implementing Classes:
AbstractFlowExecutionRepository, AbstractSnapshottingFlowExecutionRepository, DefaultFlowExecutionRepository
public interface FlowExecutionRepository
Central subsystem interface responsible for the saving and restoring of flow executions, where each flow execution represents a state of an active flow definition.

Flow execution repositories are responsible for managing the storage, restoration and removal of flow executions launched by clients of the Spring Web Flow system.

When placed in a repository a FlowExecution object representing the state of a flow at a point in time is indexed under a unique FlowExecutionKey.

Author:
Erwin Vervaet, Keith Donald
See Also:

  • Method Details

    • parseFlowExecutionKey

      FlowExecutionKey parseFlowExecutionKey(String encodedKey) throws FlowExecutionRepositoryException
      Parse the string-encoded flow execution key into its object form. Essentially, the reverse of FlowExecutionKey.toString().
      Parameters:
      encodedKey - the string encoded key
      Returns:
      the parsed flow execution key, the persistent identifier for exactly one flow execution
      Throws:
      FlowExecutionRepositoryException

    • getLock

      FlowExecutionLock getLock(FlowExecutionKey key) throws FlowExecutionRepositoryException
      Return the lock for the flow execution, allowing for the lock to be acquired or released. Caution: care should be made not to allow for a deadlock situation. If you acquire a lock make sure you release it when you are done. The general pattern for safely doing work against a locked conversation follows: 
       FlowExecutionLock lock = repository.getLock(key);
 lock.lock();
 try {
        FlowExecution execution = repository.getFlowExecution(key);
        // do work
 } finally {
        lock.unlock();
 }
      Parameters:
      key - the identifier of the flow execution to lock
      Returns:
      the lock
      Throws:
      FlowExecutionRepositoryException - a problem occurred accessing the lock object

    • getFlowExecution

      FlowExecution getFlowExecution(FlowExecutionKey key) throws FlowExecutionRepositoryException
      Return the FlowExecution indexed by the provided key. The returned flow execution represents the restored state of an executing flow from a point in time. This should be called to resume a persistent flow execution. Before calling this method, you should acquire the lock for the keyed flow execution.
      Parameters:
      key - the flow execution key
      Returns:
      the flow execution, fully hydrated and ready to resume
      Throws:
      FlowExecutionRepositoryException - if no flow execution was indexed with the key provided

    • putFlowExecution

      void putFlowExecution(FlowExecution flowExecution) throws FlowExecutionRepositoryException
      Place the FlowExecution in this repository under the provided key. This should be called to save or update the persistent state of an active (but paused) flow execution. Before calling this method, you should acquire the lock for the keyed flow execution.
      Parameters:
      flowExecution - the flow execution
      Throws:
      FlowExecutionRepositoryException - the flow execution could not be stored

    • removeFlowExecution

      void removeFlowExecution(FlowExecution flowExecution) throws FlowExecutionRepositoryException
      Remove the flow execution from the repository. This should be called when the flow execution ends (is no longer active). Before calling this method, you should acquire the lock for the keyed flow execution.
      Parameters:
      flowExecution - the flow execution
      Throws:
      FlowExecutionRepositoryException - the flow execution could not be removed.