Construindo aplicativos invencíveis com Temporal e MongoDB

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git clone https://github.com/mongodb-developer/mongodb-java-money-transfer

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package org.mongodb.workflows;
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@WorkflowInterface
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public interface MoneyTransferWorkflow {
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    @WorkflowMethod
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    String transfer(TransferDetails input);
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    @SignalMethod
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    void approve(String managerName);
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}

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package org.mongodb.activities;
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@ActivityInterface
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public interface AccountActivities {
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    @ActivityMethod
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    String withdraw(String account, int amount, String referenceId);
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    @ActivityMethod
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    String deposit(String account, int amount, String referenceId);
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}

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public class MoneyTransferWorkflowImpl implements MoneyTransferWorkflow {    private final ActivityOptions options = ActivityOptions.newBuilder()
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            .setStartToCloseTimeout(Duration.ofSeconds(10))
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            .setRetryOptions(RetryOptions.newBuilder()
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                    .setInitialInterval(Duration.ofSeconds(1))
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                    .setMaximumInterval(Duration.ofSeconds(60))
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                    .setBackoffCoefficient(2.0)
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                    .setDoNotRetry(
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                            InsufficientFundsException.class.getName())
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                    .build())
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            .build();
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    private final AccountActivities activitiesStub = Workflow.newActivityStub(AccountActivities.class, options);
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    @Override
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    public String transfer(TransferDetails input) {
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        String withdrawKey = String.format("withdrawal-for-%s", input.getReferenceId());
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        String withdrawResult = activitiesStub.withdraw(input.getSender(), input.getAmount(), withdrawKey);
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        String depositKey = String.format("deposit-for-%s", input.getReferenceId());
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        String depositResult = activitiesStub.deposit(input.getRecipient(), input.getAmount(), depositKey);
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        String confirmation = String.format("withdrawal=%s, deposit=%s", withdrawResult, depositResult);
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        return confirmation;
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    }
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}

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package org.mongodb.workers;
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public class ApplicationWorker {
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    public static final String TASK_QUEUE_NAME = "money-transfer-task-queue";
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    public static void main(String[] args) {
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        WorkflowServiceStubs serviceStub = WorkflowServiceStubs.newLocalServiceStubs();
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        WorkflowClient client = WorkflowClient.newInstance(serviceStub);
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        WorkerFactory factory = WorkerFactory.newInstance(client);
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        Worker worker = factory.newWorker(TASK_QUEUE_NAME);
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        worker.registerWorkflowImplementationTypes(MoneyTransferWorkflowImpl.class);
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        AccountActivities activities = new AccountActivitiesImpl();
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        worker.registerActivitiesImplementations(activities);
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        factory.start();
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    }
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}

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package org.mongodb;
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public class Starter {
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    private static final Logger logger = LoggerFactory.getLogger(Starter.class);
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    public static void main(String[] args) {
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       // The sender, recipient, and transfer amount are parsed from 
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       // command-line arguments. The parsing code here is omitted for brevity.
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        String referenceId = UUID.randomUUID().toString();
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        TransferDetails details = new TransferDetails(sender, recipient, transferAmount, referenceId);
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        String workflowId = String.format("transfer-%d-%s-to-%s", transferAmount, sender, recipient).toLowerCase();
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        WorkflowServiceStubs serviceStub = WorkflowServiceStubs.newLocalServiceStubs();
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        WorkflowClient client = WorkflowClient.newInstance(serviceStub);
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        WorkflowOptions options = WorkflowOptions.newBuilder()
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                .setTaskQueue(ApplicationWorker.TASK_QUEUE_NAME)
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                .setWorkflowId(workflowId)
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                .build();
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        MoneyTransferWorkflow workflow = client.newWorkflowStub(MoneyTransferWorkflow.class, options);
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        String confirmation = workflow.transfer(details);
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        logger.info("Money Transfer complete. Confirmation: {}", confirmation);
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        System.exit(0);
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    }
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}

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export MONGO_CONNECTION_STRING="mongodb+srv://<username>:<password>@cluster.abcde.mongodb.net/"

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set MONGO_CONNECTION_STRING="mongodb+srv://<username>:<password>@cluster.abcde.mongodb.net/"

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env:MONGO_CONNECTION_STRING="mongodb+srv://<username>:<password>@cluster.abcde.mongodb.net/"

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cd bank-services

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mvn compile exec:java -Dexec.mainClass="org.mongodb.banking.Main"

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temporal server start-dev --db-filename temporal-service.db

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cd money-transfer-application

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mvn compile exec:java -Dexec.mainClass="org.mongodb.workers.ApplicationWorker"

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mvn compile exec:java -Dexec.mainClass="org.mongodb.Starter" -Dexec.args="Maria David 100"

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[org.mongodb.Starter.main()] INFO org.mongodb.Starter - Money Transfer complete. Confirmation: withdrawal=W4842620791, deposit=D7932687105

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mvn compile exec:java -Dexec.mainClass="org.mongodb.Starter" -Dexec.args="Maria David 100"

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//Workflow.sleep(Duration.ofSeconds(30));

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mvn compile exec:java -Dexec.mainClass="org.mongodb.workers.ApplicationWorker"

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mvn compile exec:java -Dexec.mainClass="org.mongodb.Starter" -Dexec.args="Maria David 100"

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mvn compile exec:java -Dexec.mainClass="org.mongodb.workers.ApplicationWorker"

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// Large transfers must be explicitly approved by a manager
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if (input.getAmount() > 500) {
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    logger.warn("This transfer is on hold awaiting manager approval");
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    hasManagerApproval = false;
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}
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// Workflow Execution will not progress until hasManagerApproval is true
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Workflow.await(() -> hasManagerApproval);  
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// Transfer approved. Will now withdraw money from the sender's account
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logger.info("Starting withdraw operation");

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@Override
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public void approve(String managerName) {
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    logger.info("This transfer has now been approved by {}", managerName);
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    hasManagerApproval = true;
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}

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WorkflowServiceStubs service = WorkflowServiceStubs.newLocalServiceStubs();
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WorkflowClient client = WorkflowClient.newInstance(service);
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client.newUntypedWorkflowStub(workflowId).signal("approve", managerName);

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mvn compile exec:java -Dexec.mainClass="org.mongodb.Starter" -Dexec.args="Maria David 600"