/*
* Copyright (c) 2010-2014. Axon Framework
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.axonframework.commandhandling.gateway;
import org.axonframework.commandhandling.CommandBus;
import org.axonframework.commandhandling.CommandCallback;
import org.axonframework.commandhandling.CommandDispatchInterceptor;
import org.axonframework.commandhandling.callbacks.FutureCallback;
import org.axonframework.commandhandling.callbacks.NoOpCallback;
import java.util.List;
import java.util.concurrent.TimeUnit;
import static java.util.Arrays.asList;
/**
* Default implementation of the CommandGateway interface. It allow configuration of a {@link RetryScheduler} and
* {@link CommandDispatchInterceptor CommandDispatchInterceptors}. The Retry Scheduler allows for Command to be
* automatically retried when a non-transient exception occurs. The Command Dispatch Interceptors can intercept and
* alter command dispatched on this specific gateway. Typically, this would be used to add gateway specific meta data
* to the Command.
*
* @author Allard Buijze
* @since 2.0
*/
public class DefaultCommandGateway extends AbstractCommandGateway implements CommandGateway {
/**
* Initializes a command gateway that dispatches commands to the given <code>commandBus</code> after they have been
* handles by the given <code>commandDispatchInterceptors</code>. Commands will not be retried when command
* execution fails.
*
* @param commandBus The CommandBus on which to dispatch the Command Messages
* @param commandDispatchInterceptors The interceptors to invoke before dispatching commands to the Command Bus
*/
public DefaultCommandGateway(CommandBus commandBus, CommandDispatchInterceptor... commandDispatchInterceptors) {
this(commandBus, null, commandDispatchInterceptors);
}
/**
* Initializes a command gateway that dispatches commands to the given <code>commandBus</code> after they have been
* handles by the given <code>commandDispatchInterceptors</code>. When command execution results in an unchecked
* exception, the given <code>retryScheduler</code> is invoked to allow it to retry that command.
* execution fails.
*
* @param commandBus The CommandBus on which to dispatch the Command Messages
* @param retryScheduler The scheduler that will decide whether to reschedule commands
* @param commandDispatchInterceptors The interceptors to invoke before dispatching commands to the Command Bus
*/
public DefaultCommandGateway(CommandBus commandBus, RetryScheduler retryScheduler,
CommandDispatchInterceptor... commandDispatchInterceptors) {
this(commandBus, retryScheduler, asList(commandDispatchInterceptors));
}
/**
* Initializes a command gateway that dispatches commands to the given <code>commandBus</code> after they have been
* handles by the given <code>commandDispatchInterceptors</code>. When command execution results in an unchecked
* exception, the given <code>retryScheduler</code> is invoked to allow it to retry that command.
* execution fails.
*
* @param commandBus The CommandBus on which to dispatch the Command Messages
* @param retryScheduler The scheduler that will decide whether to reschedule commands
* @param commandDispatchInterceptors The interceptors to invoke before dispatching commands to the Command Bus
*/
public DefaultCommandGateway(CommandBus commandBus, RetryScheduler retryScheduler,
List<CommandDispatchInterceptor> commandDispatchInterceptors) {
super(commandBus, retryScheduler, commandDispatchInterceptors);
}
@Override
public <R> void send(Object command, CommandCallback<R> callback) {
super.send(command, callback);
}
/**
* Sends the given <code>command</code> and waits for its execution to complete, or until the waiting thread is
* interrupted.
*
* @param command The command to send
* @param <R> The expected type of return value
* @return The result of the command handler execution
*
* @throws org.axonframework.commandhandling.CommandExecutionException
* when command execution threw a checked exception
*/
@Override
@SuppressWarnings("unchecked")
public <R> R sendAndWait(Object command) {
FutureCallback<Object> futureCallback = new FutureCallback<Object>();
send(command, futureCallback);
return (R) futureCallback.getResult();
}
/**
* Sends the given <code>command</code> and waits for its execution to complete, or until the given
* <code>timeout</code> has expired, or the waiting thread is interrupted.
* <p/>
* When the timeout occurs, or the thread is interrupted, this method returns <code>null</code>.
*
* @param command The command to send
* @param timeout The maximum time to wait
* @param unit The time unit of the timeout argument
* @param <R> The expected type of return value
* @return The result of the command handler execution
*
* @throws org.axonframework.commandhandling.CommandExecutionException
* when command execution threw a checked exception
*/
@Override
@SuppressWarnings("unchecked")
public <R> R sendAndWait(Object command, long timeout, TimeUnit unit) {
FutureCallback<Object> futureCallback = new FutureCallback<Object>();
send(command, futureCallback);
return (R) futureCallback.getResult(timeout, unit);
}
/**
* Sends the given <code>command</code> and returns immediately. This implementation
*
* @param command The command to send
*/
@Override
public void send(Object command) {
send(command, new NoOpCallback());
}
}