Java tutorial
/* * Copyright 2015 The Netty Project * * The Netty Project 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 io.netty.channel.pool; import io.netty.channel.Channel; import io.netty.channel.EventLoop; import io.netty.util.concurrent.Future; import io.netty.util.concurrent.Promise; /** * Called before a {@link Channel} will be returned via {@link ChannelPool#acquire()} or * {@link ChannelPool#acquire(Promise)}. */ public interface ChannelHealthChecker { /** * {@link ChannelHealthChecker} implementation that checks if {@link Channel#isActive()} returns {@code true}. */ ChannelHealthChecker ACTIVE = new ChannelHealthChecker() { @Override public Future<Boolean> isHealthy(Channel channel) { EventLoop loop = channel.eventLoop(); return channel.isActive() ? loop.newSucceededFuture(Boolean.TRUE) : loop.newSucceededFuture(Boolean.FALSE); } }; /** * Check if the given channel is healthy which means it can be used. The returned {@link Future} is notified once * the check is complete. If notified with {@link Boolean#TRUE} it can be used {@link Boolean#FALSE} otherwise. * * This method will be called by the {@link EventLoop} of the {@link Channel}. */ Future<Boolean> isHealthy(Channel channel); }