本文主要是介绍Spring Retry 在SpringBoot 中的应用，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
Spring Boot中使用Spring-Retry重试框架
Spring Retry提供了自动重新调用失败的操作的功能。这在错误可能是暂时的（例如瞬时网络故障）的情况下很有用。 从2.2.0版本开始，重试功能已从Spring Batch中撤出，成为一个独立的新库：Spring Retry
Maven依赖
<dependency><groupId>org.springframework.retry</groupId><artifactId>spring-retry</artifactId> </dependency> <!-- also need to add Spring AOP into our project--> <dependency><groupId>org.springframework</groupId><artifactId>spring-aspects</artifactId> </dependency>
注解使用
开启Retry功能
在启动类中使用@EnableRetry注解
package org.example;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.retry.annotation.EnableRetry;@SpringBootApplication
@EnableRetry
public class RetryApp {public static void main(String[] args) {SpringApplication.run(RetryApp.class, args);}
}
注解 @Retryable
需要在重试的代码中加入重试注解 @Retryable
package org.example;import lombok.extern.slf4j.Slf4j;
import org.springframework.retry.annotation.Backoff;
import org.springframework.retry.annotation.Recover;
import org.springframework.retry.annotation.Retryable;
import org.springframework.stereotype.Service;import java.time.LocalDateTime;@Service
@Slf4j
public class RetryService {@Retryable(value = IllegalAccessException.class)public void service1() throws IllegalAccessException {log.info("do something... {}", LocalDateTime.now());throw new IllegalAccessException("manual exception");}
}
默认情况下，会重试3次，间隔1秒
我们可以从注解 @Retryable 中看到
@Target({ ElementType.METHOD, ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Retryable {/*** Retry interceptor bean name to be applied for retryable method. Is mutually* exclusive with other attributes.* @return the retry interceptor bean name*/String interceptor() default "";/*** Exception types that are retryable. Synonym for includes(). Defaults to empty (and* if excludes is also empty all exceptions are retried).* @return exception types to retry*/Class<? extends Throwable>[] value() default {};/*** Exception types that are retryable. Defaults to empty (and if excludes is also* empty all exceptions are retried).* @return exception types to retry*/Class<? extends Throwable>[] include() default {};/*** Exception types that are not retryable. Defaults to empty (and if includes is also* empty all exceptions are retried).* If includes is empty but excludes is not, all not excluded exceptions are retried* @return exception types not to retry*/Class<? extends Throwable>[] exclude() default {};/*** A unique label for statistics reporting. If not provided the caller may choose to* ignore it, or provide a default.** @return the label for the statistics*/String label() default "";/*** Flag to say that the retry is stateful: i.e. exceptions are re-thrown, but the* retry policy is applied with the same policy to subsequent invocations with the* same arguments. If false then retryable exceptions are not re-thrown.* @return true if retry is stateful, default false*/boolean stateful() default false;/*** @return the maximum number of attempts (including the first failure), defaults to 3*/int maxAttempts() default 3; //默认重试次数3次/*** @return an expression evaluated to the maximum number of attempts (including the first failure), defaults to 3* Overrides {@link #maxAttempts()}.* @since 1.2*/String maxAttemptsExpression() default "";/*** Specify the backoff properties for retrying this operation. The default is a* simple {@link Backoff} specification with no properties - see it's documentation* for defaults.* @return a backoff specification*/Backoff backoff() default @Backoff(); //默认的重试中的退避策略/*** Specify an expression to be evaluated after the {@code SimpleRetryPolicy.canRetry()}* returns true - can be used to conditionally suppress the retry. Only invoked after* an exception is thrown. The root object for the evaluation is the last {@code Throwable}.* Other beans in the context can be referenced.* For example:* <pre class=code>* {@code "message.contains('you can retry this')"}.* </pre>* and* <pre class=code>* {@code "@someBean.shouldRetry(#root)"}.* </pre>* @return the expression.* @since 1.2*/String exceptionExpression() default "";/*** Bean names of retry listeners to use instead of default ones defined in Spring context* @return retry listeners bean names*/String[] listeners() default {};}
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Backoff {/*** Synonym for {@link #delay()}.** @return the delay in milliseconds (default 1000)*/long value() default 1000; //默认的重试间隔1秒/*** A canonical backoff period. Used as an initial value in the exponential case, and* as a minimum value in the uniform case.* @return the initial or canonical backoff period in milliseconds (default 1000)*/long delay() default 0;/*** The maximimum wait (in milliseconds) between retries. If less than the* {@link #delay()} then the default of* {@value org.springframework.retry.backoff.ExponentialBackOffPolicy#DEFAULT_MAX_INTERVAL}* is applied.** @return the maximum delay between retries (default 0 = ignored)*/long maxDelay() default 0;/*** If positive, then used as a multiplier for generating the next delay for backoff.** @return a multiplier to use to calculate the next backoff delay (default 0 =* ignored)*/double multiplier() default 0;/*** An expression evaluating to the canonical backoff period. Used as an initial value* in the exponential case, and as a minimum value in the uniform case. Overrides* {@link #delay()}.* @return the initial or canonical backoff period in milliseconds.* @since 1.2*/String delayExpression() default "";/*** An expression evaluating to the maximimum wait (in milliseconds) between retries.* If less than the {@link #delay()} then the default of* {@value org.springframework.retry.backoff.ExponentialBackOffPolicy#DEFAULT_MAX_INTERVAL}* is applied. Overrides {@link #maxDelay()}** @return the maximum delay between retries (default 0 = ignored)* @since 1.2*/String maxDelayExpression() default "";/*** Evaluates to a vaule used as a multiplier for generating the next delay for* backoff. Overrides {@link #multiplier()}.** @return a multiplier expression to use to calculate the next backoff delay (default* 0 = ignored)* @since 1.2*/String multiplierExpression() default "";/*** In the exponential case ({@link #multiplier()} > 0) set this to true to have the* backoff delays randomized, so that the maximum delay is multiplier times the* previous delay and the distribution is uniform between the two values.** @return the flag to signal randomization is required (default false)*/boolean random() default false;}
我们来运行测试代码
package org.example;import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;@SpringBootTest
class RetryServiceTest {@Autowiredprivate RetryService retryService;@Testvoid testService1() throws IllegalAccessException {retryService.service1();}
}
运行结果如下：
2021-01-05 19:40:41.221 INFO 3548 --- [ main] org.example.RetryService : do something... 2021-01-05T19:40:41.221763300 2021-01-05 19:40:42.224 INFO 3548 --- [ main] org.example.RetryService : do something... 2021-01-05T19:40:42.224436500 2021-01-05 19:40:43.225 INFO 3548 --- [ main] org.example.RetryService : do something... 2021-01-05T19:40:43.225189300java.lang.IllegalAccessException: manual exceptionat org.example.RetryService.service1(RetryService.java:19)at org.example.RetryService$$FastClassBySpringCGLIB$$c0995ddb.invoke(<generated>)at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769)at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)at org.springframework.retry.interceptor.RetryOperationsInterceptor$1.doWithRetry(RetryOperationsInterceptor.java:91)at org.springframework.retry.support.RetryTemplate.doExecute(RetryTemplate.java:287)at org.springframework.retry.support.RetryTemplate.execute(RetryTemplate.java:164)at org.springframework.retry.interceptor.RetryOperationsInterceptor.invoke(RetryOperationsInterceptor.java:118)at org.springframework.retry.annotation.AnnotationAwareRetryOperationsInterceptor.invoke(AnnotationAwareRetryOperationsInterceptor.java:153)at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)at org.example.RetryService$$EnhancerBySpringCGLIB$$499afa1d.service1(<generated>)at org.example.RetryServiceTest.testService1(RetryServiceTest.java:16)at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.base/java.lang.reflect.Method.invoke(Method.java:566)at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:675)at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:125)at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:132)at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:124)at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:74)at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:104)at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:62)at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:43)at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:35)at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:202)at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMetho
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