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How SpringBoot integrates Retry to implement error retry

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Release: 2023-05-19 22:11:32
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    Introducing dependencies

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-aop</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.retry</groupId>
        <artifactId>spring-retry</artifactId>
    </dependency>
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    Complete dependencies on pom.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.7.7</version>
            <relativePath/> <!-- lookup parent from repository -->
        </parent>
        <groupId>com.example</groupId>
        <artifactId>demo</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>demo</name>
        <description>Demo project for Spring Boot</description>
        <properties>
            <java.version>1.8</java.version>
        </properties>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
                <scope>runtime</scope>
                <optional>true</optional>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <!-- spring-retry -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-aop</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.retry</groupId>
                <artifactId>spring-retry</artifactId>
            </dependency>
        </dependencies>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <configuration>
                        <excludes>
                            <exclude>
                                <groupId>org.projectlombok</groupId>
                                <artifactId>lombok</artifactId>
                            </exclude>
                        </excludes>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </project>
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    Enable spring-retry

    Add to startup class Annotation @EnableRetry

    package com.example.demo;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.retry.annotation.EnableRetry;
    @EnableRetry
    @SpringBootApplication
    public class Application {
        public static void main(String[] args) {
            SpringApplication.run(Application.class, args);
        }
    }
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    Use retry annotation

    @Retryable annotation

    • value, retryable exception type. The meaning is the same as include. The default is empty (if excludes is also empty, all exceptions will be retried)

    • include: retryable exception types. The default is empty (if excludes is also empty, all exceptions will be retried)

    • exclude: Exception types that do not need to be retried. The default is empty (if includes is also empty, all exceptions will be retried)

    • maxAttempts: The maximum number of retries (including the first failure), the default is 3 times

    • backoff: Retry waiting strategy, which will be introduced in @Backoff below

    • recover: Indicates the callback method after the number of retries reaches the maximum number of retries

    @Backoff annotation

    • delay, the waiting time between retries (in milliseconds)

    • maxDelay, the maximum waiting time between retries (in milliseconds)

    • multiplier, specify the multiple of delay

    • delayExpression , the waiting time expression between retries

    • maxDelayExpression, the maximum waiting time expression between retries

    • multiplierExpression, specifying the delay Multiple expression

    • random, randomly specify the delay time

    Usage example

    package com.example.demo.component;
    import org.springframework.retry.annotation.Recover;
    import org.springframework.retry.annotation.Retryable;
    import org.springframework.stereotype.Component;
    @Component
    public class HttpRequest {
        private int count = 0;
        /**
         * 模拟网络请求异常
         * @return
         */
        @Retryable(recover = "errorHandler")
        public String getResponse() {
            count++;
            System.out.println("time: " + count);
            if (count < 4) {
                throw new RuntimeException("count: " + count);
            }
            return "success";
        }
        /**
         * 错误处理函数
         * 注意:需要返回 String,否则会抛出方法找不到异常
         * org.springframework.retry.ExhaustedRetryException: Cannot locate recovery method
         *
         * @param e
         * @return
         */
        @Recover
        public String errorHandler(RuntimeException e) {
            System.out.println("errorHandler");
            return "ok";
        }
    }
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    Test

    package com.example.demo.component;
    import org.junit.jupiter.api.Test;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    @SpringBootTest
    public class HttpRequestTest {
        @Autowired
        private HttpRequest httpRequest;
        @Test
        public void getResponse(){
            httpRequest.getResponse();
        }
    }
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    Output result

    time: 1
    time: 2
    time: 3
    errorHandler

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