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/* * Copyright 2014-2019 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.amqp.rabbit.config; import org.aopalliance.intercept.MethodInterceptor; import org.springframework.amqp.rabbit.retry.MessageKeyGenerator; import org.springframework.amqp.rabbit.retry.MessageRecoverer; import org.springframework.amqp.rabbit.retry.NewMessageIdentifier; import org.springframework.retry.RetryOperations; import org.springframework.retry.RetryPolicy; import org.springframework.retry.backoff.BackOffPolicy; import org.springframework.retry.backoff.ExponentialBackOffPolicy; import org.springframework.retry.interceptor.RetryOperationsInterceptor; import org.springframework.retry.interceptor.StatefulRetryOperationsInterceptor; import org.springframework.retry.policy.SimpleRetryPolicy; import org.springframework.retry.support.RetryTemplate; import org.springframework.util.Assert; /** * <p>Simplified facade to make it easier and simpler to build a * {@link StatefulRetryOperationsInterceptor} or * (stateless) {@link RetryOperationsInterceptor} * by providing a fluent interface to defining the behavior on error. * <p> * Typical example: * </p> * * <pre class="code"> * StatefulRetryOperationsInterceptor interceptor = * RetryInterceptorBuilder.stateful() * .maxAttempts(5) * .backOffOptions(1, 2, 10) // initialInterval, multiplier, maxInterval * .build(); * </pre> * <p> * When building a stateful interceptor, a message identifier is required. * The default behavior determines message identity based on {@code messageId}. * This isn't a required field and may not be set by the sender. * If it is not, you can change the logic to determine message * identity using a custom generator:</p> * <pre class="code"> * StatefulRetryOperationsInterceptor interceptor = RetryInterceptorBuilder.stateful() * .messageKeyGenerator(new MyMessageKeyGenerator()) * .build(); * </pre> * * @param <B> The target {@link RetryInterceptorBuilder} implementation type. * @param <T> The type of {@link MethodInterceptor} returned by the builder's {@link #build()} method. * * @author James Carr * @author Gary Russell * @author Artem Bilan * * @since 1.3 * */ public abstract class RetryInterceptorBuilder<B extends RetryInterceptorBuilder<B, T>, T extends MethodInterceptor> { private RetryOperations retryOperations; private final RetryTemplate retryTemplate = new RetryTemplate(); private final SimpleRetryPolicy simpleRetryPolicy = new SimpleRetryPolicy(); private MessageRecoverer messageRecoverer; private boolean templateAltered; private boolean backOffPolicySet; private boolean retryPolicySet; private boolean backOffOptionsSet; /** * Create a builder for a stateful retry interceptor. * @return The interceptor builder. */ public static StatefulRetryInterceptorBuilder stateful() { return new StatefulRetryInterceptorBuilder(); } /** * Create a builder for a stateless retry interceptor. * @return The interceptor builder. */ public static StatelessRetryInterceptorBuilder stateless() { return new StatelessRetryInterceptorBuilder(); } @SuppressWarnings("unchecked") protected final B _this() { // NOSONAR starts with _ return (B) this; } /** * Apply the retry operations - once this is set, other properties can no longer be set; can't * be set if other properties have been applied. * @param retryOperations The retry operations. * @return this. */ public B retryOperations(RetryOperations retryOperations) { Assert.isTrue(!this.templateAltered, "Cannot set retryOperations when the default has been modified"); this.retryOperations = retryOperations; return _this(); } /** * Apply the max attempts - a SimpleRetryPolicy will be used. Cannot be used if a custom retry operations * or retry policy has been set. * @param maxAttempts the max attempts. * @return this. */ public B maxAttempts(int maxAttempts) { Assert.isNull(this.retryOperations, "cannot alter the retry policy when a custom retryOperations has been set"); Assert.isTrue(!this.retryPolicySet, "cannot alter the retry policy when a custom retryPolicy has been set"); this.simpleRetryPolicy.setMaxAttempts(maxAttempts); this.retryTemplate.setRetryPolicy(this.simpleRetryPolicy); this.templateAltered = true; return _this(); } /** * Apply the backoff options. Cannot be used if a custom retry operations, or back off policy has been set. * @param initialInterval The initial interval. * @param multiplier The multiplier. * @param maxInterval The max interval. * @return this. */ public B backOffOptions(long initialInterval, double multiplier, long maxInterval) { Assert.isNull(this.retryOperations, "cannot set the back off policy when a custom retryOperations has been set"); Assert.isTrue(!this.backOffPolicySet, "cannot set the back off options when a back off policy has been set"); ExponentialBackOffPolicy policy = new ExponentialBackOffPolicy(); policy.setInitialInterval(initialInterval); policy.setMultiplier(multiplier); policy.setMaxInterval(maxInterval); this.retryTemplate.setBackOffPolicy(policy); this.backOffOptionsSet = true; this.templateAltered = true; return _this(); } /** * Apply the retry policy - cannot be used if a custom retry template has been provided, or the max attempts or * back off options or policy have been applied. * @param policy The policy. * @return this. */ public B retryPolicy(RetryPolicy policy) { Assert.isNull(this.retryOperations, "cannot set the retry policy when a custom retryOperations has been set"); Assert.isTrue(!this.templateAltered, "cannot set the retry policy if max attempts or back off policy or options changed"); this.retryTemplate.setRetryPolicy(policy); this.retryPolicySet = true; this.templateAltered = true; return _this(); } /** * Apply the back off policy. Cannot be used if a custom retry operations, or back off policy has been applied. * @param policy The policy. * @return this. */ public B backOffPolicy(BackOffPolicy policy) { Assert.isNull(this.retryOperations, "cannot set the back off policy when a custom retryOperations has been set"); Assert.isTrue(!this.backOffOptionsSet, "cannot set the back off policy when the back off policy options have been set"); this.retryTemplate.setBackOffPolicy(policy); this.templateAltered = true; this.backOffPolicySet = true; return _this(); } /** * Apply a Message recoverer - default is to log and discard after retry is exhausted. * @param recoverer The recoverer. * @return this. */ public B recoverer(MessageRecoverer recoverer) { this.messageRecoverer = recoverer; return _this(); } protected void applyCommonSettings(AbstractRetryOperationsInterceptorFactoryBean factoryBean) { if (this.messageRecoverer != null) { factoryBean.setMessageRecoverer(this.messageRecoverer); } if (this.retryOperations != null) { factoryBean.setRetryOperations(this.retryOperations); } else { factoryBean.setRetryOperations(this.retryTemplate); } } public abstract T build(); /** * Builder for a stateful interceptor. */ public static final class StatefulRetryInterceptorBuilder extends RetryInterceptorBuilder<StatefulRetryInterceptorBuilder, StatefulRetryOperationsInterceptor> { private final StatefulRetryOperationsInterceptorFactoryBean factoryBean = new StatefulRetryOperationsInterceptorFactoryBean(); private MessageKeyGenerator messageKeyGenerator; private NewMessageIdentifier newMessageIdentifier; StatefulRetryInterceptorBuilder() { super(); } /** * Stateful retry requires messages to be identifiable. Default is to use the message id header; use a custom * implementation if the message id is not present or not reliable. * @param messageKeyGenerator The key generator. * @return this. */ public StatefulRetryInterceptorBuilder messageKeyGenerator(MessageKeyGenerator messageKeyGenerator) { this.messageKeyGenerator = messageKeyGenerator; return this; } /** * Apply a custom new message identifier. Default is to use the redelivered header. * @param newMessageIdentifier The new message identifier. * @return this. */ public StatefulRetryInterceptorBuilder newMessageIdentifier(NewMessageIdentifier newMessageIdentifier) { this.newMessageIdentifier = newMessageIdentifier; return this; } @Override public StatefulRetryOperationsInterceptor build() { this.applyCommonSettings(this.factoryBean); if (this.messageKeyGenerator != null) { this.factoryBean.setMessageKeyGenerator(this.messageKeyGenerator); } if (this.newMessageIdentifier != null) { this.factoryBean.setNewMessageIdentifier(this.newMessageIdentifier); } return this.factoryBean.getObject(); } } /** * Builder for a stateless interceptor. */ public static final class StatelessRetryInterceptorBuilder extends RetryInterceptorBuilder<StatelessRetryInterceptorBuilder, RetryOperationsInterceptor> { private final StatelessRetryOperationsInterceptorFactoryBean factoryBean = new StatelessRetryOperationsInterceptorFactoryBean(); StatelessRetryInterceptorBuilder() { super(); } @Override public RetryOperationsInterceptor build() { this.applyCommonSettings(this.factoryBean); return this.factoryBean.getObject(); } } }