org.apfloat.samples.RemoteOperationExecutor Maven / Gradle / Ivy
/*
* MIT License
*
* Copyright (c) 2002-2023 Mikko Tommila
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package org.apfloat.samples;
import java.net.InetSocketAddress;
import java.nio.channels.Channels;
import java.nio.channels.SocketChannel;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
/**
* Class to call an {@link OperationServer} to execute {@link Operation}s remotely.
*
* @version 1.9.0
* @author Mikko Tommila
*/
public class RemoteOperationExecutor
implements OperationExecutor
{
/**
* Create a new client that will connect to the server
* running at the specified host and port.
*
* @param host Hostname of the remote server.
* @param port Port of the remote server.
*/
public RemoteOperationExecutor(String host, int port)
{
this.host = host;
this.port = port;
}
/**
* Execute an operation remotely.
* This method will block until the return value has been received.
*
* @param operation The operation to execute remotely.
*
* @return The result of the operation.
*
* @exception RuntimeException In case of network error or if the return value class is unknown.
*/
@Override
public T execute(Operation operation)
{
T result;
try (SocketChannel channel = SocketChannel.open(new InetSocketAddress(this.host, this.port)))
{
ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(Channels.newOutputStream(channel), BUFFER_SIZE));
out.writeObject(operation);
out.flush();
ObjectInputStream in = new ObjectInputStream(Channels.newInputStream(channel));
@SuppressWarnings("unchecked")
T obj = (T) in.readObject();
result = obj;
}
catch (IOException | ClassNotFoundException e)
{
throw new RuntimeException(e);
}
return result;
}
/**
* Execute an operation remotely.
* This method starts a new thread running the remote call and returns immediately.
*
* @param operation The operation to execute remotely.
*
* @return A {@link BackgroundOperation} for retrieving the result of the operation later.
*/
@Override
public BackgroundOperation executeBackground(Operation operation)
{
return new BackgroundOperation<>(() -> RemoteOperationExecutor.this.execute(operation));
}
@Override
public int getWeight()
{
return 1;
}
/**
* Returns the host name.
*
* @return The host name.
*/
public String getHost()
{
return this.host;
}
/**
* Returns the host port.
*
* @return The host port.
*/
public int getPort()
{
return this.port;
}
private static final int BUFFER_SIZE = 8192;
private String host;
private int port;
}