com.amazonaws.services.simpleworkflow.flow.core

Class Task

java.lang.Object

com.amazonaws.services.simpleworkflow.flow.core.Task

public abstract class Task
extends Object

Asynchronous task that is executed when all Promises passed to its constructor are ready (null parameter is considered ready).

Should be created in the context of AsyncScope.doAsync() method, from doExecute() or from TryCatchFinally do... methods. Exceptions thrown from doExecute() are delivered asynchronously to the wrapping TryCatchFinally.doCatch(Throwable) method or rethrown from AsyncScope.eventLoop() if no wrapping TryCatchFinally is found.

Example of using Task to implement asynchronous function that sums parameters when both of them are ready:

 
 public Promise<Integer> sum(Promise<Integer> a, Promise<Integer> b) {
     Settable<Integer> result = new Settable<Integer>();
     new Task(a, b) {
         public void doExecute() {
             result.set(a.get() + b.get());
         }
     };
     return result;
 }
 
 

See Also:

AsyncScope, TryCatchFinally, Promise

Constructor Summary

Constructors

Modifier	Constructor and Description
	Task(com.amazonaws.services.simpleworkflow.flow.core.AsyncContextAware parent, boolean daemon, Promise<?>... waitFor)
protected	Task(com.amazonaws.services.simpleworkflow.flow.core.AsyncContextAware parent, Boolean daemon, String parentTaskMethodName, boolean hideParentTaskMethodName, int skipStackLines, Promise<?>... waitFor)
	Task(com.amazonaws.services.simpleworkflow.flow.core.AsyncContextAware parent, Promise<?>... waitFor)
	Task(boolean daemon, Promise<?>... waitFor)
protected	Task(Boolean daemon, String parentTaskMethodName, boolean hideParentTaskMethodName, int skipStackLines, Promise<?>... waitFor)
	Task(Promise<?>... waitFor)

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract void	doExecute()
String	getName()
StackTraceElement[]	getStackTrace()
void	setName(String name)
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Task

public Task(Promise<?>... waitFor)

Task

public Task(boolean daemon,
    Promise<?>... waitFor)

Task

public Task(com.amazonaws.services.simpleworkflow.flow.core.AsyncContextAware parent,
    boolean daemon,
    Promise<?>... waitFor)

Task

public Task(com.amazonaws.services.simpleworkflow.flow.core.AsyncContextAware parent,
    Promise<?>... waitFor)

Task

protected Task(com.amazonaws.services.simpleworkflow.flow.core.AsyncContextAware parent,
    Boolean daemon,
    String parentTaskMethodName,
    boolean hideParentTaskMethodName,
    int skipStackLines,
    Promise<?>... waitFor)

Task

protected Task(Boolean daemon,
    String parentTaskMethodName,
    boolean hideParentTaskMethodName,
    int skipStackLines,
    Promise<?>... waitFor)

Method Detail

getName

public String getName()

setName

public void setName(String name)

getStackTrace

public StackTraceElement[] getStackTrace()

toString

public String toString()

Overrides:

toString in class Object

doExecute

protected abstract void doExecute()
                           throws Throwable

Throws:

Throwable