io.cdap.cdap.api.workflow

Interface WorkflowToken

@Beta
public interface WorkflowToken

Interface to represent the data that is transferred from one node to the next nodes in the Workflow.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	WorkflowToken.Scope Keys in the WorkflowToken can be added by user, using the put(java.lang.String, java.lang.String) method.

Method Summary

Modifier and Type	Method and Description
Value	get(String key) Get the most recent value added for the specified key for a WorkflowToken.Scope.USER scope.
Value	get(String key, String nodeName) Get the value set for the specified key by the specified node for a WorkflowToken.Scope.USER scope.
Value	get(String key, String nodeName, WorkflowToken.Scope scope) Get the value set for the specified key by the specified node for a given scope.
Value	get(String key, WorkflowToken.Scope scope) Get the most recent value for the specified key for a given scope.
Map<String,List<NodeValue>>	getAll() Same key can be added to the WorkflowToken by multiple nodes.
List<NodeValue>	getAll(String key) Same key can be added to the WorkflowToken by multiple nodes.
List<NodeValue>	getAll(String key, WorkflowToken.Scope scope) Same key can be added to the WorkflowToken by multiple nodes.
Map<String,List<NodeValue>>	getAll(WorkflowToken.Scope scope) Same key can be added to the WorkflowToken by multiple nodes.
Map<String,Value>	getAllFromNode(String nodeName) Get the Map of key to Values that were added to the WorkflowToken by specific node for a WorkflowToken.Scope.USER scope.
Map<String,Value>	getAllFromNode(String nodeName, WorkflowToken.Scope scope) Get the Map of key to Values that were added to the WorkflowToken by specific node for a given scope.
void	put(String key, String value) Put the specified key and value into the WorkflowToken.
void	put(String key, Value value) Put the specified key and Value into the WorkflowToken.

Method Detail

put

void put(String key,
         String value)

Put the specified key and value into the WorkflowToken. The token may store additional information about the context in which this key is being set. For example, the context information stored by the token may be the workflow node that is performing the operation, or the name of the workflow if the operation is performed in AbstractWorkflow.initialize(io.cdap.cdap.api.workflow.WorkflowContext) or AbstractWorkflow.destroy() method.

Parameters:

key - the key representing the entry

value - the value for the key

Throws:

UnsupportedOperationException - if called in a context where the token may not be modified.

put

void put(String key,
         Value value)

Put the specified key and Value into the WorkflowToken. The token may store additional information about the context in which this key is being set. For example, the context information stored by the token may be the workflow node that is performing the operation, or the name of the workflow if the operation is performed in AbstractWorkflow.initialize(io.cdap.cdap.api.workflow.WorkflowContext) or AbstractWorkflow.destroy() method.

Parameters:

key - the key representing entry

value - the Value for the key

Throws:

UnsupportedOperationException - if called in a context where the token may not be modified.

get

@Nullable
Value get(String key)

Get the most recent value added for the specified key for a WorkflowToken.Scope.USER scope.

Parameters:

key - the key to be searched

Returns:

the Value for the key or null if the key does not exist in the WorkflowToken.Scope.USER scope

get

@Nullable
Value get(String key,
                    WorkflowToken.Scope scope)

Get the most recent value for the specified key for a given scope.

Parameters:

key - the key to be searched

scope - the WorkflowToken.Scope for the key

Returns:

the Value for the key from the specified scope or null if the key does not exist in the given scope

get

@Nullable
Value get(String key,
                    String nodeName)

Get the value set for the specified key by the specified node for a WorkflowToken.Scope.USER scope. To get the token values set from AbstractWorkflow.initialize(io.cdap.cdap.api.workflow.WorkflowContext) or AbstractWorkflow.destroy() methods, provide the name of the Workflow as nodeName.

Parameters:

key - the key to be searched

nodeName - the name of the node

Returns:

the Value set for the key by nodeName or null if the key is not added by the nodeName in the WorkflowToken.Scope.USER scope

get

@Nullable
Value get(String key,
                    String nodeName,
                    WorkflowToken.Scope scope)

Get the value set for the specified key by the specified node for a given scope. To get the token values set from AbstractWorkflow.initialize(io.cdap.cdap.api.workflow.WorkflowContext) or AbstractWorkflow.destroy() methods, provide the name of the Workflow as nodeName.

Parameters:

key - the key to be searched

nodeName - the name of the node

scope - the WorkflowToken.Scope for the key

Returns:

the Value set for the key by nodeName for a given scope or null if the key is not added by the nodeName in the given scope

getAll

List<NodeValue> getAll(String key)

Same key can be added to the WorkflowToken by multiple nodes. This method returns the List of NodeValue, where each entry represents the unique node name and the Value that it set for the specified key for a WorkflowToken.Scope.USER scope.

The list maintains the order in which the values were inserted in the WorkflowToken for a specific key except in the case of fork and join. In case of fork in the Workflow, copies of the WorkflowToken are made and passed along each branch. At the join, all copies of the WorkflowToken are merged together. While merging, the order in which the values were inserted for a specific key is guaranteed within the same branch, but not across different branches.

Parameters:

key - the key to be searched

Returns:

the list of NodeValue from node name to the value that node added for the input key

getAll

List<NodeValue> getAll(String key,
                       WorkflowToken.Scope scope)

Same key can be added to the WorkflowToken by multiple nodes. This method returns the List of NodeValue, where each entry represents the unique node name and the Value that it set for the specified key for a given scope.

The list maintains the order in which the values were inserted in the WorkflowToken for a specific key except in the case of fork and join. In case of fork in the Workflow, copies of the WorkflowToken are made and passed along each branch. At the join, all copies of the WorkflowToken are merged together. While merging, the order in which the values were inserted for a specific key is guaranteed within the same branch, but not across different branches.

Parameters:

key - the key to be searched

scope - the WorkflowToken.Scope for the key

Returns:

the list of NodeValue from node name to the value that node added for the input key for a given scope

getAllFromNode

Map<String,Value> getAllFromNode(String nodeName)

Get the Map of key to Values that were added to the WorkflowToken by specific node for a WorkflowToken.Scope.USER scope. To get the token values set from AbstractWorkflow.initialize(io.cdap.cdap.api.workflow.WorkflowContext) or AbstractWorkflow.destroy() methods, provide the name of the Workflow as nodeName.

Parameters:

nodeName - the unique name of the node

Returns:

the map of key to values that were added by the specified node

getAllFromNode

Map<String,Value> getAllFromNode(String nodeName,
                                 WorkflowToken.Scope scope)

Get the Map of key to Values that were added to the WorkflowToken by specific node for a given scope. To get the token values set from AbstractWorkflow.initialize(io.cdap.cdap.api.workflow.WorkflowContext) or AbstractWorkflow.destroy() methods, provide the name of the Workflow as nodeName.

Parameters:

nodeName - the unique name of the node

scope - the WorkflowToken.Scope for the key

Returns:

the map of key to values that were added by the specified node for a given scope

getAll

Map<String,List<NodeValue>> getAll()

Same key can be added to the WorkflowToken by multiple nodes. This method returns the key to List of NodeValue added in the WorkflowToken.Scope.USER scope.

Returns:

the Map of key to List of NodeValue added for the given scope

getAll

Map<String,List<NodeValue>> getAll(WorkflowToken.Scope scope)

Same key can be added to the WorkflowToken by multiple nodes. This method returns the key to List of NodeValue added in the WorkflowToken.Scope provided.

Parameters:

scope - the scope for the key

Returns:

the Map of key to List of NodeValue added for the given scope