如何編寫swf初學者程序

Question

我是AWS SWF的新手，嘗試創建一些活動，工作流和工作流啓動器。 我發現了很多例子，在他們的幫助下，我現在可以註冊一個域，創建一些活動並創建一個工作流，但是我無法編寫一個程序來啓動我的工作流執行。

有人可以幫助我在這裏。下面是我的代碼至今：

ActivityWorker.java：

@Activities 
@ActivityRegistrationOptions(
    defaultTaskHeartbeatTimeoutSeconds = FlowConstants.NONE, 
    defaultTaskScheduleToCloseTimeoutSeconds = 300, 
    defaultTaskScheduleToStartTimeoutSeconds = FlowConstants.NONE, 
    defaultTaskStartToCloseTimeoutSeconds = 300) 
public interface ActivityWorker { 
@Activity(name = "swftest1", version = "1.0") 
@ExponentialRetry(
     initialRetryIntervalSeconds=10, 
     backoffCoefficient=1, 
     maximumAttempts=5) 
public String print() throws IOException; 


@Activity(name = "swftest2", version = "1.0") 
@ExponentialRetry(
     initialRetryIntervalSeconds=10, 
     backoffCoefficient=1, 
     maximumAttempts=5) 
public String print2() throws IOException; 

} 

ActivityWorkerImpl.java

public class ActivityWorkerImpl implements ActivityWorker{ 

@Override 
public String print() throws IOException { 
    System.out.println("Hello.."); 
    return "Printing.."; 
} 

@Override 
public String print2() throws IOException { 
    System.out.println("Hello.."); 
    return "Printing2.."; 
} 
} 

Worker.java

@Workflow 
@WorkflowRegistrationOptions(
    defaultExecutionStartToCloseTimeoutSeconds = 600, 
    defaultTaskStartToCloseTimeoutSeconds = 300) 
public interface Worker { 
@Execute(version = "1.0", name="worker1") 
public void greet(); 

} 

WorkerImpl.java

public class WorkerImpl implements Worker{ 

private final ActivityWorkerImpl actWorkerImpl = new ActivityWorkerImpl(); 

@Override 
public void greet() { 
    new TryCatchFinally() { 
     @Override 
     protected void doTry() throws Throwable { 
      String res= downloadFromS3(); 
      System.out.println("res.."+res); 
     } 

     @Override 
     protected void doCatch(Throwable e) throws Throwable { 
      throw e; 
     } 

     @Override 
     protected void doFinally() throws Throwable { 
      // noop 
     } 
    }; 
} 


@Asynchronous 
private String downloadFromS3() throws IOException { 
    return this.actWorkerImpl.print(); 
} 

} 

Host.java

public class ActivityHost { 

    public static void main(String[] args) throws Exception { 

      String domain = "test1"; 
      String taskListToPoll = "HelloWorldList"; 

     ClientConfiguration config = new ClientConfiguration().withSocketTimeout(70*1000); 

     String swfAccessId = "myid"; 
     String swfSecretKey = "mysecretekey"; 
     AWSCredentials awsCredentials = new BasicAWSCredentials(swfAccessId, swfSecretKey); 

     AmazonSimpleWorkflow swf = new AmazonSimpleWorkflowClient(awsCredentials, config); 

     ActivityWorker activityworker = new ActivityWorker(swf, domain, taskListToPoll); 
     //adding activity 
     activityworker.addActivitiesImplementation(new ActivityWorkerImpl()); 

     activityworker.start(); 

     //adding workflow 
     WorkflowWorker worker = new WorkflowWorker(swf,domain, taskListToPoll); 

     worker.addWorkflowImplementationType(WorkerImpl.class); 

     worker.start(); 
    } 

} 

Aftere運行Host.java，我能看到在AWS控制檯，但如何觸發我的工作流程，我無法弄清楚我的活動和工作流程。

有人可以幫我在這裏。

Answer 1

使用產生的外部客戶端開始工作流執行：

WorkerClientExternalFactory f = new WorkerClientExternalFActory (swf, domain); 
WorkerClientExternal w = f.getClient(); 
w.greet(); 

我建議要通過AWS流程框架Examples和Recipes，因爲它們包含工作端到端的各種方案的示例。

在你的代碼中你有一個返回String的@Asynchronous方法。這是不允許的，因爲這種方法必須返回void或Promise。您的工作流程代碼不應直接引用活動實施，而只能通過生成的客戶端。

編輯： 工廠和客戶端由註釋處理器生成。根據"Setting up the AWS Flow Framework for Java"文檔中關於啓用代碼生成的說明。