org.apache.sshd.common.Closeable Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.sshd.common;
import java.io.IOException;
import java.net.SocketTimeoutException;
import java.nio.channels.Channel;
import java.time.Duration;
import org.apache.sshd.common.future.CloseFuture;
import org.apache.sshd.common.future.SshFutureListener;
/**
* A {@code Closeable} is a resource that can be closed. The close method is invoked to release resources that the
* object is holding. The user can pre-register listeners to be notified when resource close is completed (successfully
* or otherwise)
*
* @author Apache MINA SSHD Project
*/
public interface Closeable extends Channel {
/**
* Close this resource asynchronously and return a future. Resources support two closing modes: a graceful mode
* which will cleanly close the resource and an immediate mode which will close the resources abruptly.
*
* @param immediately true if the resource should be shut down abruptly, false for a
* graceful close
* @return a {@link CloseFuture} representing the close request
*/
CloseFuture close(boolean immediately);
/**
* Pre-register a listener to be informed when resource is closed. If resource is already closed, the listener will
* be invoked immediately and not registered for future notification
*
* @param listener The notification {@link SshFutureListener} - never {@code null}
*/
void addCloseFutureListener(SshFutureListener listener);
/**
* Remove a pre-registered close event listener
*
* @param listener The register {@link SshFutureListener} - never {@code null}. Ignored if not registered or
* resource already closed
*/
void removeCloseFutureListener(SshFutureListener listener);
/**
* Returns true if this object has been closed.
*
* @return true if closing
*/
boolean isClosed();
/**
* Returns true if the {@link #close(boolean)} method has been called. Note that this method will
* return true even if this {@link #isClosed()} returns true.
*
* @return true if closing
*/
boolean isClosing();
@Override
default boolean isOpen() {
return !(isClosed() || isClosing());
}
@Override
default void close() throws IOException {
Closeable.close(this);
}
static Duration getMaxCloseWaitTime(PropertyResolver resolver) {
return CommonModuleProperties.CLOSE_WAIT_TIMEOUT.getRequired(resolver);
}
static void close(Closeable closeable) throws IOException {
if (closeable == null) {
return;
}
if ((!closeable.isClosed()) && (!closeable.isClosing())) {
CloseFuture future = closeable.close(true);
Duration maxWait = (closeable instanceof PropertyResolver)
? getMaxCloseWaitTime((PropertyResolver) closeable)
: CommonModuleProperties.CLOSE_WAIT_TIMEOUT.getRequiredDefault();
boolean successful = future.await(maxWait);
if (!successful) {
throw new SocketTimeoutException("Failed to receive closure confirmation within " + maxWait + " millis");
}
}
}
}