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Introduce Builder API and factory methods for RetryPolicy
Prior to this commit, we had three concrete RetryPolicy implementations. - MaxRetryAttemptsPolicy - MaxDurationAttemptsPolicy - PredicateRetryPolicy However, there was no way to combine the behavior of those policies. Furthermore, the PredicateRetryPolicy was practically useless as a standalone policy, since it did not have a way to end an infinite loop for a Retryable that continually throws an exception which matches the predicate. This commit therefore replaces the current built-in RetryPolicy implementations with a fluent Builder API and dedicated factory methods for common use cases. In addition, this commit also introduces built-in support for specifying include/exclude lists. Examples: new MaxRetryAttemptsPolicy(5) --> RetryPolicy.withMaxAttempts(5) new MaxDurationAttemptsPolicy(Duration.ofSeconds(5)) --> RetryPolicy.withMaxDuration(Duration.ofSeconds(5)) new PredicateRetryPolicy(IOException.class::isInstance) --> RetryPolicy.builder() .maxAttempts(3) .predicate(IOException.class::isInstance) .build(); The following example demonstrates all supported features of the builder. RetryPolicy.builder() .maxAttempts(5) .maxDuration(Duration.ofMillis(100)) .includes(IOException.class) .excludes(FileNotFoundException.class) .predicate(t -> t.getMessage().contains("Unexpected failure")) .build(); Closes gh-35058
1 parent 945f3fb commit 97522cf

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+713
-537
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‎spring-core/src/main/java/org/springframework/core/retry/DefaultRetryPolicy.java‎

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/*
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* Copyright 2002-2025 the original author or authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* https://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.springframework.core.retry;
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import java.time.Duration;
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import java.time.LocalDateTime;
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import java.util.Set;
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import java.util.StringJoiner;
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import java.util.function.Predicate;
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import org.jspecify.annotations.Nullable;
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import org.springframework.util.Assert;
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/**
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* Default {@link RetryPolicy} created by {@link RetryPolicy.Builder}.
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*
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* @author Sam Brannen
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* @author Mahmoud Ben Hassine
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* @since 7.0
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*/
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class DefaultRetryPolicy implements RetryPolicy {
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private final int maxAttempts;
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private final @Nullable Duration maxDuration;
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private final Set<Class<? extends Throwable>> includes;
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private final Set<Class<? extends Throwable>> excludes;
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private final @Nullable Predicate<Throwable> predicate;
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DefaultRetryPolicy(int maxAttempts, @Nullable Duration maxDuration, Set<Class<? extends Throwable>> includes,
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Set<Class<? extends Throwable>> excludes, @Nullable Predicate<Throwable> predicate) {
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Assert.isTrue((maxAttempts > 0 || maxDuration != null), "Max attempts or max duration must be specified");
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this.maxAttempts = maxAttempts;
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this.maxDuration = maxDuration;
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this.includes = includes;
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this.excludes = excludes;
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this.predicate = predicate;
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}
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@Override
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public RetryExecution start() {
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return new DefaultRetryPolicyExecution();
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}
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@Override
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public String toString() {
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StringJoiner result = new StringJoiner(", ", "DefaultRetryPolicy[", "]");
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if (this.maxAttempts > 0) {
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result.add("maxAttempts=" + this.maxAttempts);
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}
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if (this.maxDuration != null) {
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result.add("maxDuration=" + this.maxDuration.toMillis() + "ms");
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}
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if (!this.includes.isEmpty()) {
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result.add("includes=" + names(this.includes));
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}
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if (!this.excludes.isEmpty()) {
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result.add("excludes=" + names(this.excludes));
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}
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if (this.predicate != null) {
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result.add("predicate=" + this.predicate.getClass().getSimpleName());
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}
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return result.toString();
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}
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private static String names(Set<Class<? extends Throwable>> types) {
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StringJoiner result = new StringJoiner(", ", "[", "]");
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for (Class<? extends Throwable> type : types) {
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String name = type.getCanonicalName();
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result.add(name != null? name : type.getName());
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}
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return result.toString();
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}
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/**
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* {@link RetryExecution} for {@link DefaultRetryPolicy}.
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*/
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private class DefaultRetryPolicyExecution implements RetryExecution {
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private final LocalDateTime retryStartTime = LocalDateTime.now();
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private int retryCount;
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@Override
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public boolean shouldRetry(Throwable throwable) {
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if (DefaultRetryPolicy.this.maxAttempts > 0 &&
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this.retryCount++ >= DefaultRetryPolicy.this.maxAttempts) {
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return false;
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}
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if (DefaultRetryPolicy.this.maxDuration != null) {
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Duration retryDuration = Duration.between(this.retryStartTime, LocalDateTime.now());
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if (retryDuration.compareTo(DefaultRetryPolicy.this.maxDuration) > 0) {
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return false;
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}
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}
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if (!DefaultRetryPolicy.this.excludes.isEmpty()) {
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for (Class<? extends Throwable> excludedType : DefaultRetryPolicy.this.excludes) {
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if (excludedType.isInstance(throwable)) {
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return false;
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}
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}
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}
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if (!DefaultRetryPolicy.this.includes.isEmpty()) {
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boolean included = false;
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for (Class<? extends Throwable> includedType : DefaultRetryPolicy.this.includes) {
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if (includedType.isInstance(throwable)) {
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included = true;
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break;
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}
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}
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if (!included) {
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return false;
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}
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}
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return DefaultRetryPolicy.this.predicate == null || DefaultRetryPolicy.this.predicate.test(throwable);
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}
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@Override
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public String toString() {
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StringJoiner result = new StringJoiner(", ", "DefaultRetryPolicyExecution[", "]");
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if (DefaultRetryPolicy.this.maxAttempts > 0) {
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result.add("maxAttempts=" + DefaultRetryPolicy.this.maxAttempts);
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result.add("retryCount=" + this.retryCount);
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}
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if (DefaultRetryPolicy.this.maxDuration != null) {
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result.add("maxDuration=" + DefaultRetryPolicy.this.maxDuration.toMillis() + "ms");
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result.add("retryStartTime=" + this.retryStartTime);
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}
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if (!DefaultRetryPolicy.this.includes.isEmpty()) {
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result.add("includes=" + names(DefaultRetryPolicy.this.includes));
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}
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if (!DefaultRetryPolicy.this.excludes.isEmpty()) {
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result.add("excludes=" + names(DefaultRetryPolicy.this.excludes));
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}
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if (DefaultRetryPolicy.this.predicate != null) {
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result.add("predicate=" + DefaultRetryPolicy.this.predicate.getClass().getSimpleName());
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}
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return result.toString();
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}
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}
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}

‎spring-core/src/main/java/org/springframework/core/retry/RetryPolicy.java‎

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package org.springframework.core.retry;
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import java.time.Duration;
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import java.util.Collections;
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import java.util.LinkedHashSet;
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import java.util.Set;
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import java.util.function.Predicate;
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import org.jspecify.annotations.Nullable;
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import org.springframework.util.Assert;
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/**
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* Strategy interface to define a retry policy.
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*
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* <p>Also provides factory methods and a fluent builder API for creating retry
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* policies with common configurations. See {@link #withMaxAttempts(int)},
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* {@link #withMaxDuration(Duration)}, {@link #builder()}, and the configuration
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* options in {@link Builder} for details.
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*
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* @author Sam Brannen
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* @author Mahmoud Ben Hassine
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* @since 7.0
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* @see RetryExecution
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*/
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public interface RetryPolicy {
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*/
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RetryExecution start();
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/**
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* Create a {@link RetryPolicy} configured with a maximum number of retry attempts.
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* @param maxAttempts the maximum number of retry attempts; must be greater than zero
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* @see Builder#maxAttempts(int)
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*/
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static RetryPolicy withMaxAttempts(int maxAttempts) {
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return builder().maxAttempts(maxAttempts).build();
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}
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/**
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* Create a {@link RetryPolicy} configured with a maximum retry {@link Duration}.
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* @param maxDuration the maximum retry duration; must be positive
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* @see Builder#maxDuration(Duration)
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*/
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static RetryPolicy withMaxDuration(Duration maxDuration) {
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return builder().maxDuration(maxDuration).build();
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}
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/**
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* Create a {@link Builder} to configure a {@link RetryPolicy} with common
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* configuration options.
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*/
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static Builder builder() {
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return new Builder();
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}
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/**
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* Fluent API for configuring a {@link RetryPolicy} with common configuration
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* options.
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*/
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final class Builder {
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private int maxAttempts;
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private @Nullable Duration maxDuration;
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private final Set<Class<? extends Throwable>> includes = new LinkedHashSet<>();
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private final Set<Class<? extends Throwable>> excludes = new LinkedHashSet<>();
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private @Nullable Predicate<Throwable> predicate;
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private Builder() {
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// internal constructor
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}
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/**
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* Specify the maximum number of retry attempts.
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* @param maxAttempts the maximum number of retry attempts; must be
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* greater than zero
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* @return this {@code Builder} instance for chained method invocations
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*/
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public Builder maxAttempts(int maxAttempts) {
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Assert.isTrue(maxAttempts > 0, "Max attempts must be greater than zero");
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this.maxAttempts = maxAttempts;
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return this;
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}
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/**
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* Specify the maximum retry {@link Duration}.
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* @param maxDuration the maximum retry duration; must be positive
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* @return this {@code Builder} instance for chained method invocations
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*/
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public Builder maxDuration(Duration maxDuration) {
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Assert.isTrue(!maxDuration.isNegative() && !maxDuration.isZero(), "Max duration must be positive");
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this.maxDuration = maxDuration;
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return this;
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}
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/**
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* Specify the types of exceptions for which the {@link RetryPolicy}
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* should retry a failed operation.
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* <p>This can be combined with {@link #excludes(Class...)} and
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* {@link #predicate(Predicate)}.
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* @param types the types of exceptions to include in the policy
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* @return this {@code Builder} instance for chained method invocations
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*/
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@SafeVarargs // Making the method final allows us to use @SafeVarargs.
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@SuppressWarnings("varargs")
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public final Builder includes(Class<? extends Throwable>... types) {
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Collections.addAll(this.includes, types);
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return this;
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}
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/**
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* Specify the types of exceptions for which the {@link RetryPolicy}
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* should not retry a failed operation.
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* <p>This can be combined with {@link #includes(Class...)} and
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* {@link #predicate(Predicate)}.
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* @param types the types of exceptions to exclude from the policy
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* @return this {@code Builder} instance for chained method invocations
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*/
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@SafeVarargs // Making the method final allows us to use @SafeVarargs.
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@SuppressWarnings("varargs")
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public final Builder excludes(Class<? extends Throwable>... types) {
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Collections.addAll(this.excludes, types);
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return this;
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}
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/**
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* Specify a custom {@link Predicate} that the {@link RetryPolicy} will
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* use to determine whether to retry a failed operation based on a given
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* {@link Throwable}.
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* <p>If a predicate has already been configured, the supplied predicate
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* will be {@linkplain Predicate#and(Predicate) combined} with the
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* existing predicate.
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* <p>This can be combined with {@link #includes(Class...)} and
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* {@link #excludes(Class...)}.
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* @param predicate a custom predicate
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* @return this {@code Builder} instance for chained method invocations
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*/
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public Builder predicate(Predicate<Throwable> predicate) {
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this.predicate = (this.predicate != null ? this.predicate.and(predicate) : predicate);
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return this;
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}
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/**
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* Build the {@link RetryPolicy} configured via this {@code Builder}.
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*/
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public RetryPolicy build() {
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return new DefaultRetryPolicy(this.maxAttempts, this.maxDuration,
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this.includes, this.excludes, this.predicate);
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}
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}
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}

‎spring-core/src/main/java/org/springframework/core/retry/RetryTemplate.java‎

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import org.jspecify.annotations.Nullable;
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import org.springframework.core.log.LogAccessor;
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import org.springframework.core.retry.support.MaxRetryAttemptsPolicy;
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import org.springframework.util.Assert;
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import org.springframework.util.backoff.BackOff;
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import org.springframework.util.backoff.BackOffExecution;
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private static final LogAccessor logger = new LogAccessor(RetryTemplate.class);
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private RetryPolicy retryPolicy = new MaxRetryAttemptsPolicy();
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private RetryPolicy retryPolicy = RetryPolicy.withMaxAttempts(3);
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private BackOff backOffPolicy = new FixedBackOff(Duration.ofSeconds(1));
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/**
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* Set the {@link RetryPolicy} to use.
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* <p>Defaults to {@code new MaxRetryAttemptsPolicy()}.
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* <p>Defaults to {@code RetryPolicy.withMaxAttempts(3)}.
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* @param retryPolicy the retry policy to use
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* @see MaxRetryAttemptsPolicy
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* @see RetryPolicy#withMaxAttempts(int)
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* @see RetryPolicy#withMaxDuration(Duration)
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* @see RetryPolicy#builder()
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*/
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public void setRetryPolicy(RetryPolicy retryPolicy) {
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Assert.notNull(retryPolicy, "Retry policy must not be null");

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