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/* * Copyright 2002-2019 the original author or authors. * * 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 * * https://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.springframework.integration.channel; import java.util.ArrayDeque; import java.util.Deque; import java.util.List; import org.springframework.integration.support.management.PollableChannelManagement; import org.springframework.integration.support.management.metrics.CounterFacade; import org.springframework.integration.support.management.metrics.MetricsCaptor; import org.springframework.lang.Nullable; import org.springframework.messaging.Message; import org.springframework.messaging.PollableChannel; import org.springframework.messaging.support.ChannelInterceptor; import org.springframework.messaging.support.ExecutorChannelInterceptor; /** * Base class for all pollable channels. * * @author Mark Fisher * @author Artem Bilan * @author Gary Russell * @author Artem Bilan */ public abstract class AbstractPollableChannel extends AbstractMessageChannel implements PollableChannel, PollableChannelManagement, ExecutorChannelInterceptorAware { private int executorInterceptorsSize; private CounterFacade receiveCounter; @Override public int getReceiveCount() { return getMetrics().getReceiveCount(); } @Override public long getReceiveCountLong() { return getMetrics().getReceiveCountLong(); } @Override public int getReceiveErrorCount() { return getMetrics().getReceiveErrorCount(); } @Override public long getReceiveErrorCountLong() { return getMetrics().getReceiveErrorCountLong(); } /** * Receive the first available message from this channel. If the channel * contains no messages, this method will block. * @return the first available message or <code>null</code> if the * receiving thread is interrupted. */ @Override @Nullable public Message<?> receive() { return receive(-1); } /** * Receive the first available message from this channel. If the channel * contains no messages, this method will block until the allotted timeout * elapses. If the specified timeout is 0, the method will return * immediately. If less than zero, it will block indefinitely (see * {@link #receive()}). * @param timeout the timeout in milliseconds * @return the first available message or <code>null</code> if no message * is available within the allotted time or the receiving thread is * interrupted. */ @Override // NOSONAR complexity @Nullable public Message<?> receive(long timeout) { ChannelInterceptorList interceptorList = getIChannelInterceptorList(); Deque<ChannelInterceptor> interceptorStack = null; boolean counted = false; boolean countsEnabled = isCountsEnabled(); boolean traceEnabled = isLoggingEnabled() && logger.isTraceEnabled(); try { if (traceEnabled) { logger.trace("preReceive on channel '" + this + "'"); } if (interceptorList.getSize() > 0) { interceptorStack = new ArrayDeque<>(); if (!interceptorList.preReceive(this, interceptorStack)) { return null; } } Message<?> message = doReceive(timeout); if (message == null) { if (traceEnabled) { logger.trace("postReceive on channel '" + this + "', message is null"); } } else { if (countsEnabled) { incrementReceiveCounter(); getMetrics().afterReceive(); counted = true; } if (logger.isDebugEnabled()) { logger.debug("postReceive on channel '" + this + "', message: " + message); } } if (interceptorStack != null && message != null) { message = interceptorList.postReceive(message, this); } interceptorList.afterReceiveCompletion(message, this, null, interceptorStack); return message; } catch (RuntimeException ex) { if (countsEnabled && !counted) { incrementReceiveErrorCounter(ex); } interceptorList.afterReceiveCompletion(null, this, ex, interceptorStack); throw ex; } } private void incrementReceiveCounter() { MetricsCaptor metricsCaptor = getMetricsCaptor(); if (metricsCaptor != null) { if (this.receiveCounter == null) { this.receiveCounter = buildReceiveCounter(metricsCaptor, null); } this.receiveCounter.increment(); } } private void incrementReceiveErrorCounter(Exception ex) { MetricsCaptor metricsCaptor = getMetricsCaptor(); if (metricsCaptor != null) { buildReceiveCounter(metricsCaptor, ex).increment(); } getMetrics().afterError(); } private CounterFacade buildReceiveCounter(MetricsCaptor metricsCaptor, @Nullable Exception ex) { CounterFacade counterFacade = metricsCaptor.counterBuilder(RECEIVE_COUNTER_NAME) .tag("name", getComponentName() == null ? "unknown" : getComponentName()).tag("type", "channel") .tag("result", ex == null ? "success" : "failure") .tag("exception", ex == null ? "none" : ex.getClass().getSimpleName()) .description("Messages received").build(); this.meters.add(counterFacade); return counterFacade; } @Override public void setInterceptors(List<ChannelInterceptor> interceptors) { super.setInterceptors(interceptors); for (ChannelInterceptor interceptor : interceptors) { if (interceptor instanceof ExecutorChannelInterceptor) { this.executorInterceptorsSize++; } } } @Override public void addInterceptor(ChannelInterceptor interceptor) { super.addInterceptor(interceptor); if (interceptor instanceof ExecutorChannelInterceptor) { this.executorInterceptorsSize++; } } @Override public void addInterceptor(int index, ChannelInterceptor interceptor) { super.addInterceptor(index, interceptor); if (interceptor instanceof ExecutorChannelInterceptor) { this.executorInterceptorsSize++; } } @Override public boolean removeInterceptor(ChannelInterceptor interceptor) { boolean removed = super.removeInterceptor(interceptor); if (removed && interceptor instanceof ExecutorChannelInterceptor) { this.executorInterceptorsSize--; } return removed; } @Override @Nullable public ChannelInterceptor removeInterceptor(int index) { ChannelInterceptor interceptor = super.removeInterceptor(index); if (interceptor instanceof ExecutorChannelInterceptor) { this.executorInterceptorsSize--; } return interceptor; } @Override public boolean hasExecutorInterceptors() { return this.executorInterceptorsSize > 0; } /** * Subclasses must implement this method. A non-negative timeout indicates * how long to wait if the channel is empty (if the value is 0, it must * return immediately with or without success). A negative timeout value * indicates that the method should block until either a message is * available or the blocking thread is interrupted. * @param timeout The timeout. * @return The message, or null. */ @Nullable protected abstract Message<?> doReceive(long timeout); }