Package com.google.cloud.spanner

Interface AsyncTransactionManager.AsyncTransactionStep<I,O>

All Superinterfaces:

com.google.api.core.ApiFuture<O>, Future<O>

Enclosing interface:

AsyncTransactionManager

public static interface AsyncTransactionManager.AsyncTransactionStep<I,O>
extends com.google.api.core.ApiFuture<O>

AsyncTransactionManager.AsyncTransactionStep is returned by TransactionContextFuture#then(AsyncTransactionFunction) and AsyncTransactionStep#then(AsyncTransactionFunction) and allows transaction steps that should be executed serially to be chained together. Each step can contain one or more statements that may execute in parallel.

Example usage:

 final String column = "FirstName";
 final long singerId = 1L;
 AsyncTransactionManager manager = client.transactionManagerAsync();
 TransactionContextFuture txnFuture = manager.beginAsync();
 txnFuture
   .then((transaction, ignored) ->
     transaction.readRowAsync("Singers", Key.of(singerId), Collections.singleton(column)),
     executor)
   .then((transaction, row) ->
     transaction.bufferAsync(
         Mutation.newUpdateBuilder("Singers")
           .set(column).to(row.getString(column).toUpperCase())
           .build()),
     executor)
   .commitAsync();
 

Method Summary

Modifier and Type	Method	Description
AsyncTransactionManager.CommitTimestampFuture	commitAsync()	Commits the transaction and returns a AsyncTransactionManager.CommitTimestampFuture that will return the commit timestamp of the transaction, or throw the first uncaught exception in the transaction chain as an ExecutionException.
<RES> AsyncTransactionManager.AsyncTransactionStep<O,RES>	then(AsyncTransactionManager.AsyncTransactionFunction<O,RES> next, Executor executor)	Adds a step to the transaction chain that should be executed using the specified executor.

Methods inherited from interface com.google.api.core.ApiFuture

addListener

Methods inherited from interface java.util.concurrent.Future

cancel, get, get, isCancelled, isDone

Method Detail

then

<RES> AsyncTransactionManager.AsyncTransactionStep<O,RES> then(AsyncTransactionManager.AsyncTransactionFunction<O,RES> next,
                                                                     Executor executor)

Adds a step to the transaction chain that should be executed using the specified executor. This step is guaranteed to be executed only after the previous step executed successfully. MoreExecutors.directExecutor() can be be used for lightweight functions, but should be avoided for heavy or blocking operations. See also ListenableFuture.addListener(Runnable, Executor) for further information.

commitAsync

AsyncTransactionManager.CommitTimestampFuture commitAsync()

Commits the transaction and returns a AsyncTransactionManager.CommitTimestampFuture that will return the commit timestamp of the transaction, or throw the first uncaught exception in the transaction chain as an ExecutionException.