org.apache.dubbo.rpc

Class FutureContext

java.lang.Object

org.apache.dubbo.rpc.FutureContext

public class FutureContext
extends Object

Used for async call scenario. But if the method you are calling has a CompletableFuture signature you do not need to use this class since you will get a Future response directly.

Remember to save the Future reference before making another call using the same thread, otherwise, the current Future will be override by the new one, which means you will lose the chance get the return value.

Constructor Summary

Constructors

Constructor and Description
FutureContext()

Method Summary

Modifier and Type	Method and Description
<T> CompletableFuture<T>	getCompatibleCompletableFuture() Deprecated.
<T> CompletableFuture<T>	getCompletableFuture() get future.
static FutureContext	getContext()
void	setCompatibleFuture(CompletableFuture<?> compatibleFuture) Deprecated.
void	setFuture(CompletableFuture<?> future) set future.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FutureContext

public FutureContext()

Method Detail

getContext

public static FutureContext getContext()

getCompletableFuture

public <T> CompletableFuture<T> getCompletableFuture()

get future.

Type Parameters:

T -

Returns:

future

setFuture

public void setFuture(CompletableFuture<?> future)

set future.

Parameters:

future -

getCompatibleCompletableFuture

@Deprecated
public <T> CompletableFuture<T> getCompatibleCompletableFuture()

Deprecated.

setCompatibleFuture

@Deprecated
public void setCompatibleFuture(CompletableFuture<?> compatibleFuture)

Deprecated.

Guarantee 'using org.apache.dubbo.rpc.RpcContext.getFuture() before proxy returns' can work, a typical scenario is:

      public final class TracingFilter implements Filter {
          public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
              Result result = invoker.invoke(invocation);
              Future<Object> future = rpcContext.getFuture();
              if (future instanceof FutureAdapter) {
                  ((FutureAdapter) future).getFuture().setCallback(new FinishSpanCallback(span));
               }
              ......
          }
      }
 

Start from 2.7.3, you don't have to get Future from RpcContext, we recommend using Result directly:

      public final class TracingFilter implements Filter {
          public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
              Result result = invoker.invoke(invocation);
              result.getResponseFuture().whenComplete(new FinishSpanCallback(span));
              ......
          }
      }