Spring Boot中使用Spring Retry重试框架的操作方法
目录
- Spring Retry 在SpringBoot 中的应用
- Maven依赖
- 注解使用
- 开启Retry功能
- 注解@Retryable
- 注解@Recover
- 注解@CircuitBreaker
- RetryTemplate
- RetryTemplate配置
- 使用RetryTemplate
- RetryPolicy
- BackOffPolicy
- RetryListener
- 参考
Spring Retry 在SpringBoot 中的应用
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).
Class<? extends Throwable>[] include() default {};
* Exception types that are not retryable. Defaults to empty (and if includes is also
* 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
* {@code "@someBean.shouldRetry(#root)"}.
* @return the expression.
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
* is applied. Overrides {@link #maxDelay()}
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)
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 {
@Autowired
private RetryService retryService;
@Test
void 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... 2021-01-05T19:40:43.225189300
java.lang.IllegalAccessException: manual exception at 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$1.doWithRetry(RetryOperationsInterceptor.java:91) at org.springframework.retry.support.RetryTemplate.doExecute(RetryTemplate.java:287) at org.springframework.retry.support.RetryTemplate.execute(RetryTemplate.java:164) at org.springframework.retry.interceptor.RetryOperationsInterceptor.invoke(RetryOperationsInterceptor.java:118) at org.springframework.retry.annotation.AnnotationAwareRetryOperationsInterceptor.invoke(AnnotationAwareRetryOperationsInterceptor.java:153) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at org.springframework.aop.framework.CglibAopProxy$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$6(TestMethodTestDescriptor.java:202) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:198) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:69) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125) at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123) at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122) at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80) at java.base/java.util.ArrayList.forEach(ArrayList.java:1540) at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139) at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32) at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57) at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229) at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197) at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128) at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71) at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33) at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220) at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)
可以看到重新执行了3次service1()方法，然后间隔是1秒，然后最后还是重试失败，所以抛出了异常
既然我们看到了注解@Retryable中有这么多参数可以设置，那我们就来介绍几个常用的配置。
@Retryable(include = IllegalAccessException.class, maxAttempts = 5)
public void service2() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException("manual exception");
}
首先是maxAttempts，用于设置重试次数
2021-01-06 09:30:11.263 INFO 15612 --- [ main] org.example.RetryService : do something... 2021-01-06T09:30:11.263621900
2021-01-06 09:30:12.265 INFO 15612 --- [ main] org.example.RetryService : do something... 2021-01-06T09:30:12.265629100
2021-01-06 09:30:13.265 INFO 15612 --- [ main] org.example.RetryService : do something... 2021-01-06T09:30:13.265701
2021-01-06 09:30:14.266 INFO 15612 --- [ main] org.example.RetryService : do something... 2021-01-06T09:30:14.266705400
2021-01-06 09:30:15.266 INFO 15612 --- [ main] org.example.RetryService : do something... 2021-01-06T09:30:15.266733200java.lang.IllegalAccessException: manual exception
....
从运行结果可以看到，方法执行了5次。
下面来介绍maxAttemptsExpression的设置
@Retryable(value = IllegalAccessException.class, maxAttemptsExpression = "${maxAttempts}")
public void service3() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException("manual exception");
}
maxAttemptsExpression则可以使用表达式，比如上述就是通过获取配置中maxAttempts的值，我们可以在application.yml设置。上述其实省略掉了SpEL表达式#{....}，运行结果的话可以发现方法执行了4次..
maxAttempts: 4
我们可以使用SpEL表达式
@Retryable(value = IllegalAccessException.class, maxAttemptsExpression = "#{1+1}")
public void service3_1() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException("manual exception");
}
@Retryable(value = IllegalAccessException.class, maxAttemptsExpression = "#{${maxAttempts}}")//效果和上面的一样
public void service3_2() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException("manual exception");
}
接着我们下面来看看exceptionExpression, 一样也是写SpEL表达式
@Retryable(value = IllegalAccessException.class, exceptionExpression = "message.contains('test')")
public void service4(String exceptionMessage) throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException(exceptionMessage);
}
@Retryable(value = IllegalAccessException.class, exceptionExpression = "#{message.contains('test')}")
public void service4_3(String exceptionMessage) throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException(exceptionMessage);
}
上面的表达式exceptionExpression = "message.contains('test')"的作用其实是获取到抛出来exception的message(调用了getMessage()方法)，然后判断message的内容里面是否包含了test字符串，如果包含的话就会执行重试。所以如果调用方法的时候传入的参数exceptionMessage中包含了test字符串的话就会执行重试。
但这里值得注意的是, Spring Retry 1.2.5之后exceptionExpression是可以省略掉#{...}
Since Spring Retry 1.2.5, for exceptionExpression, templated expressions (#{...}) are deprecated in favor of simple expression strings (message.contains('this can be retried')).
使用1.2.5之后的版本运行是没有问题的
<dependency>
<groupId>org.springframework.retry</groupId>
<artifactId>spring-retry</artifactId>
<version>1.3.0</version>
</dependency>
但是如果使用1.2.5版本之前包括1.2.5版本的话，运行的时候会报错如下：
2021-01-06 09:52:45.209 INFO 23220 --- [ main] org.example.RetryService : do something... 2021-01-06T09:52:45.209178200
org.springframework.expression.spel.SpelEvaluationException: EL1001E: Type conversion problem, cannot convert from java.lang.String to java.lang.Boolean
at org.springframework.expression.spel.support.StandardTypeConverter.convertValue(StandardTypeConverter.java:75)
at org.springframework.expression.common.ExpressionUtils.convertTypedValue(ExpressionUtils.java:57)
at org.springframework.expression.common.LiteralExpression.getValue(LiteralExpression.java:106)
at org.springframework.retry.policy.ExpressionRetryPolicy.canRetry(ExpressionRetryPolicy.java:113)
at org.springframework.retry.support.RetryTemplate.canRetry(RetryTemplate.java:375)
at org.springframework.retry.support.RetryTemplate.doExecute(RetryTemplate.java:304)
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$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:691)
at org.example.RetryService$$EnhancerBySpringCGLIB$$d321a75e.service4(<generated>)
at org.example.RetryServiceTest.testService4_2(RetryServiceTest.java:46)
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:686)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
at org.junit.jupiter.engine.execution.ExecutableInvoker$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:106)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
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$6(TestMethodTestDescriptor.java:212)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:208)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:137)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:71)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:248)
at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$5(DefaultLauncher.java:211)
at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:226)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:199)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:132)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)
Caused by: org.springframework.core.convert.ConversionFailedException: Failed to convert from type [java.lang.String] to type [java.lang.Boolean] for value 'message.contains('test')'; nested exception is java.lang.IllegalArgumentException: Invalid boolean value 'message.contains('test')'
at org.springframework.core.convert.support.ConversionUtils.invokeConverter(ConversionUtils.java:47)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:191)
at org.springframework.expression.spel.support.StandardTypeConverter.convertValue(StandardTypeConverter.java:70)
... 76 more
Caused by: java.lang.IllegalArgumentException: Invalid boolean value 'message.contains('test')'
at org.springframework.core.convert.support.StringToBooleanConverter.convert(StringToBooleanConverter.java:63)
at org.springframework.core.convert.support.StringToBooleanConverter.convert(StringToBooleanConverter.java:31)
at org.springframework.core.convert.support.GenericConversionService$ConverterAdapter.convert(GenericConversionService.java:385)
at org.springframework.core.convert.support.ConversionUtils.invokeConverter(ConversionUtils.java:41)
... 78 more
还可以在表达式中执行一个方法，前提是方法的类在spring容器中注册了，@retryService其实就是获取bean name为retryService的bean，然后调用里面的checkException方法，传入的参数为#root，它其实就是抛出来的exception对象。一样的也是可以省略#{...}
@Retryable(value = IllegalAccessException.class, exceptionExpression = "#{@retryService.checkException(#root)}")
public void service5(String exceptionMessage) throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException(exceptionMessage);
}
@Retryable(value = IllegalAccessException.class, exceptionExpression = "@retryService.checkException(#root)")
public void service5_1(String exceptionMessage) throws IllegalAccessException {
public boolean checkException(Exception e) {
log.error("error message:{}", e.getMessage());
return true; //返回true的话表明会执行重试，如果返回false则不会执行重试
运行结果：
2021-01-06 13:33:52.913 INFO 23052 --- [ main] org.example.RetryService : do something... 2021-01-06T13:33:52.913404
2021-01-06 13:33:52.981 ERROR 23052 --- [ main] org.example.RetryService : error message:test message
2021-01-06 13:33:53.990 ERROR 23052 --- [ main] org.example.RetryService : error message:test message
2021-01-06 13:33:53.990 INFO 23052 --- [ main] org.example.RetryService : do something... 2021-01-06T13:33:53.990947400
2021-01-06 13:33:53.990 ERROR 23052 --- [ main] org.example.RetryService : error message:test message
2021-01-06 13:33:54.992 ERROR 23052 --- [ main] org.example.RetryService : error message:test message
2021-01-06 13:33:54.992 INFO 23052 --- [ main] org.example.RetryService : do something... 2021-01-06T13:33:54.992342900
当然还有更多表达式的用法了...
@Retryable(exceptionExpression = "#{#root instanceof T(java.lang.IllegalAccessException)}") //判断exception的类型
public void service5_2(String exceptionMessage) {
log.info("do something... {}", LocalDateTime.now());
throw new NullPointerException(exceptionMessage);
}
@Retryable(exceptionExpression = "#root instanceof T(java.lang.IllegalAccessException)")
public void service5_3(String exceptionMessage) {
log.info("do something... {}", LocalDateTime.now());
throw new NullPointerException(exceptionMessage);
}
@Retryable(exceptionExpression = "myMessage.contains('test')") //查看自定义的MyException中的myMessage的值是否包含test字符串
public void service5_4(String exceptionMessage) throws MyException {
log.info("do something... {}", LocalDateTime.now());
throw new MyException(exceptionMessage); //自定义的exception
}
@Retryable(exceptionExpression = "#root.myMessage.contains('test')") //和上面service5_4方法的效果一样
public void service5_5(String exceptionMessage) throws MyException {
log.info("do something... {}", LocalDateTime.now());
throw new MyException(exceptionMessage);
}
package org.example;
import lombok.Getter;
import lombok.Setter;
@Getter
@Setter
public class MyException extends Exception {
private String myMessage;
public MyException(String myMessage) {
this.myMessage = myMessage;
}
}
下面再来看看另一个配置exclude
@Retryable(exclude = MyException.class)
public void service6(String exceptionMessage) throws MyException {
log.info("do something... {}", LocalDateTime.now());
throw new MyException(exceptionMessage);
}
这个exclude属性可以帮我们排除一些我们不想重试的异常
最后我们来看看这个backoff 重试等待策略, 默认使用@Backoff注解。
我们先来看看这个@Backoff的value属性,用于设置重试间隔
@Retryable(value = IllegalAccessException.class,
backoff = @Backoff(value = 2000))
public void service7() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException();
}
运行结果可以看出来重试的间隔为2秒
2021-01-06 14:47:38.036 INFO 21116 --- [ main] org.example.RetryService : do something... 2021-01-06T14:47:38.036732600
2021-01-06 14:47:40.038 INFO 21116 --- [ main] org.example.RetryService : do something... 2021-01-06T14:47:40.037753600
2021-01-06 14:47:42.046 INFO 21116 --- [ main] org.example.RetryService : do something... 2021-01-06T14:47:42.046642900
java.lang.IllegalAccessException
at org.example.RetryService.service7(RetryService.java:113)
...
接下来介绍@Backoff的delay属性，它与value属性不能共存，当delay不设置的时候会去读value属性设置的值，如果delay设置的话则会忽略value属性
@Retryable(value = IllegalAccessException.class,
backoff = @Backoff(value = 2000,delay = 500))
public void service8() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException();
}
运行结果可以看出，重试的时间间隔为500ms
2021-01-06 15:22:42.271 INFO 13512 --- [ main] org.example.RetryService : do something... 2021-01-06T15:22:42.271504800
2021-01-06 15:22:42.772 INFO 13512 --- [ main] org.example.RetryService : do something... 2021-01-06T15:22:42.772234900
2021-01-06 15:22:43.273 INFO 13512 --- [ main] org.example.RetryService : do something... 2021-01-06T15:22:43.273246700
java.lang.IllegalAccessException
at org.example.RetryService.service8(RetryService.java:121)
接下来我们来看``@Backoff的multiplier`的属性, 指定延迟倍数, 默认为0。
@Retryable(value = IllegalAccessException.class,maxAttempts = 4,
backoff = @Backoff(delay = 2000, multiplier = 2))
public void service9() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException();
}
multiplier设置为2，则表示第一次重试间隔为2s，第二次为4秒，第三次为8s
运行结果如下：
2021-01-06 15:58:07.458 INFO 23640 --- [ main] org.example.RetryService : do something... 2021-01-06T15:58:07.458245500
2021-01-06 15:58:09.478 INFO 23640 --- [ main] org.example.RetryService : do something... 2021-01-06T15:58:09.478681300
2021-01-06 15:58:13.478 INFO 23640 --- [ main] org.example.RetryService : do something... 2021-01-06T15:58:13.478921900
2021-01-06 15:58:21.489 INFO 23640 --- [ main] org.example.RetryService : do something... 2021-01-06T15:58:21.489240600
java.lang.IllegalAccessException
at org.example.RetryService.service9(RetryService.java:128)
...
接下来我们来看看这个@Backoff的maxDelay属性,设置最大的重试间隔，当超过这个最大的重试间隔的时候，重试的间隔就等于maxDelay的值
@Retryable(value = IllegalAccessException.class,maxAttempts = 4,
backoff = @Backoff(delay = 2000, multiplier = 2,maxDelay = 5000))
public void service10() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException();
}
运行结果：
2021-01-06 16:12:37.377 INFO 5024 --- [ main] org.example.RetryService : do something... 2021-01-06T16:12:37.377616100
2021-01-06 16:12:39.381 INFO 5024 --- [ main] org.example.RetryService : do something... 2021-01-06T16:12:39.381299400
2021-01-06 16:12:43.382 INFO 5024 --- [ main] org.example.RetryService : do something... 2021-01-06T16:12:43.382169500
2021-01-06 16:12:48.396 INFO 5024 --- [ main] org.example.RetryService : do something... 2021-01-06T16:12:48.396327600
java.lang.IllegalAccessException
at org.example.RetryService.service10(RetryService.java:135)
可以最后的最大重试间隔是5秒
注解@Recover
当@Retryable方法重试失败之后，最后就会调用@Recover方法。用于@Retryable失败时的“兜底”处理方法。 @Recover的方法必须要与@Retryable注解的方法保持一致，第一入参为要重试的异常，其他参数与@Retryable保持一致，返回值也要一样，否则无法执行！
@Retryable(value = IllegalAccessException.class)
public void service11() throws IllegalAccessException {
log.info("do something... {}", LocalDateTime.now());
throw new IllegalAccessException();
}
@Recover
public void recover11(IllegalAccessException e) {
log.info("service retry after Recover => {}", e.getMessage());
//=========================
@Retryable(value = ArithmeticException.class)
public int service12() throws IllegalAccessException {
return 1 / 0;
public int recover12(ArithmeticException e) {
return 0;
public int service13(String message) throws IllegalAccessException {
log.info("do something... {},{}", message, LocalDateTime.now());
public int recover13(ArithmeticException e, String message) {
log.info("{},service retry after Recover => {}", message, e.getMessage());
注解@CircuitBreaker
熔断模式：指在具体的重试机制下失败后打开断路器，过了一段时间，断路器进入半开状态，允许一个进入重试，若失败再次进入断路器，成功则关闭断路器，注解为@CircuitBreaker,具体包括熔断打开时间、重置过期时间
// openTimeout时间范围内失败maxAttempts次数后，熔断打开resetTimeout时长
@CircuitBreaker(openTimeout = 1000, resetTimeout = 3000, value = NullPointerException.class)
public void circuitBreaker(int num) {
log.info(" 进入断路器方法num={}", num);
if (num > 8) return;
Integer n = null;
System.err.println(1 / n);
}
@Recover
public void recover(NullPointerException e) {
log.info("service retry after Recover => {}", e.getMessage());
}
测试方法
@Test
public void testCircuitBreaker() throws InterruptedException {
System.err.println("尝试进入断路器方法，并触发异常...");
retryService.circuitBreaker(1);
retryService.circuitBreaker(1);
retryService.circuitBreaker(9);
retryService.circuitBreaker(9);
System.err.println("在openTimeout 1秒之内重试次数为2次，未达到触发熔断, 断路器依然闭合...");
TimeUnit.SECONDS.sleep(1);
System.err.println("超过openTimeout 1秒之后, 因为未触发熔断，所以重试次数重置，可以正常访问...,继续重试3次方法...");
retryService.circuitBreaker(1);
retryService.circuitBreaker(1);
retryService.circuitBreaker(1);
System.err.println("在openTimeout 1秒之内重试次数为3次，达到触发熔断，不会执行重试，只会执行恢复方法...");
retryService.circuitBreaker(1);
TimeUnit.SECONDS.sleep(2);
retryService.circuitBreaker(9);
TimeUnit.SECONDS.sleep(3);
System.err.println("超过resetTimeout 3秒之后，断路器重新闭合...,可以正常访问");
retryService.circuitBreaker(9);
retryService.circuitBreaker(9);
retryService.circuitBreaker(9);
retryService.circuitBreaker(9);
retryService.circuitBreaker(9);
}
运行结果：
尝试进入断路器方法，并触发异常...
2021-01-07 21:44:20.842 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=1
2021-01-07 21:44:20.844 INFO 7464 --- [ main] org.example.RetryService : service retry after Recover => null
2021-01-07 21:44:20.845 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=1
2021-01-07 21:44:20.845 INFO 7464 --- [ main] org.example.RetryService : service retry after Recover => null
2021-01-07 21:44:20.845 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=9
2021-01-07 21:44:20.845 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=9
在openTimeout 1秒之内重试次数为2次，未达到触发熔断, 断路器依然闭合...
超过openTimeout 1秒之后, 因为未触发熔断，所以重试次数重置，可以正常访问...,继续重试3次方法...
2021-01-07 21:44:21.846 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=1
2021-01-07 21:44:21.847 INFO 7464 --- [ main] org.example.RetryService : service retry after Recover => null
2021-01-07 21:44:21.847 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=1
2021-01-07 21:44:21.847 INFO 7464 --- [ main] org.example.RetryService : service retry after Recover => null
2021-01-07 21:44:21.847 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=1
2021-01-07 21:44:21.848 INFO 7464 --- [ main] org.example.RetryService : service retry after Recover => null
在openTimeout 1秒之内重试次数为3次，达到触发熔断，不会执行重试，只会执行恢复方法...
2021-01-07 21:44:21.848 INFO 7464 --- [ main] org.example.RetryService : service retry after Recover => null
2021-01-07 21:44:23.853 INFO 7464 --- [ main] org.example.RetryService : service retry after Recover => null
超过resetTimeout 3秒之后，断路器重新闭合...,可以正常访问
2021-01-07 21:44:26.853 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=9
2021-01-07 21:44:26.854 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=9
2021-01-07 21:44:26.855 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=9
2021-01-07 21:44:26.855 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=9
2021-01-07 21:44:26.856 INFO 7464 --- [ main] org.example.RetryService : 进入断路器方法num=9
RetryTemplate
RetryTemplate配置
package org.example;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.retry.backoff.FixedBackOffPolicy;
import org.springframework.retry.policy.SimpleRetryPolicy;
import org.springframework.retry.support.RetryTemplate;
@Configuration
public class AppConfig {
@Bean
public RetryTemplate retryTemplate() {
RetryTemplate retryTemplate = new RetryTemplate();
SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy(); //设置重试策略
retryPolicy.setMaxAttempts(2);
retryTemplate.setRetryPolicy(retryPolicy);
FixedBackOffPolicy fixedBackOffPolicy = new FixedBackOffPolicy(); //设置退避策略
fixedBackOffPolicy.setBackOffPeriod(2000L);
retryTemplate.setBackOffPolicy(fixedBackOffPolicy);
return retryTemplate;
}
}
可以看到这些配置跟我们直接写注解的方式是差不多的，这里就不过多的介绍了。。
使用RetryTemplate
package org.example;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.retry.RetryCallback;
import org.springframework.retry.RetryContext;
import org.springframework.retry.support.RetryTemplate;
@SpringBootTest
public class RetryTemplateTest {
@Autowired
private RetryTemplate retryTemplate;
private RetryTemplateService retryTemplateService;
@Test
void test1() throws IllegalAccessException {
retryTemplate.execute(new RetryCallback<Object, IllegalAccessException>() {
@Override
public Object doWithRetry(RetryContext context) throws IllegalAccessException {
retryTemplateService.service1();
return null;
}
});
}
void test2() throws IllegalAccessException {
retryTemplateService.service1();
}, new RecoveryCallback<Object>() {
public Object recover(RetryContext context) throws Exception {
log.info("RecoveryCallback....");
}
RetryOperations定义重试的API，RetryTemplate是API的模板模式实现，实现了重试和熔断。提供的API如下:
package org.springframework.retry;
import org.springframework.retry.support.DefaultRetryState;
/**
* Defines the basic set of operations implemented by {@link RetryOperations} to execute
* operations with configurable retry behaviour.
*
* @author Rob Harrop
* @author Dave Syer
*/
public interface RetryOperations {
/**
* Execute the supplied {@link RetryCallback} with the configured retry semantics. See
* implementations for configuration details.
* @param <T> the return value
* @param retryCallback the {@link RetryCallback}
* @param <E> the exception to throw
* @return the value returned by the {@link RetryCallback} upon successful invocation.
* @throws E any {@link Exception} raised by the {@link RetryCallback} upon
* unsuccessful retry.
* @throws E the exception thrown
*/
<T, E extends Throwable> T execute(RetryCallback<T, E> retryCallback) throws E;
* Execute the supplied {@link RetryCallback} with a fallback on exhausted retry to
* the {@link RecoveryCallback}. See implementations for configuration details.
* @param recoveryCallback the {@link RecoveryCallback}
* @param retryCallback the {@link RetryCallback} {@link RecoveryCallback} upon
* @param <T> the type to return
* @param <E> the type of the exception
* @return the value returned by the {@link RetryCallback} upon successful invocation,
* and that returned by the {@link RecoveryCallback} otherwise.
* @throws E any {@link Exception} raised by the unsuccessful retry.
<T, E extends Throwable> T execute(RetryCallback<T, E> retryCallback, RecoveryCallback<T> recoveryCallback)
throws E;
* A simple stateful retry. Execute the supplied {@link RetryCallback} with a target
* object for the attempt identified by the {@link DefaultRetryState}. Exceptions
* thrown by the callback are always propagated immediately so the state is required
* to be able to identify the previous attempt, if there is one - hence the state is
* required. Normal patterns would see this method being used inside a transaction,
* where the callback might invalidate the transaction if it fails.
*
* See implementations for configuration details.
* @param retryState the {@link RetryState}
* @param <T> the type of the return value
* @param <E> the type of the exception to return
* @throws E any {@link Exception} raised by the {@link RecoveryCallback}.
* @throws ExhaustedRetryException if the last attempt for this state has already been
* reached
<T, E extends Throwable> T execute(RetryCallback<T, E> retryCallback, RetryState retryState)
throws E, ExhaustedRetryException;
* A stateful retry with a recovery path. Execute the supplied {@link RetryCallback}
* with a fallback on exhausted retry to the {@link RecoveryCallback} and a target
* object for the retry attempt identified by the {@link DefaultRetryState}.
* @param <T> the return value type
* @param <E> the exception type
* @see #execute(RetryCallback, RetryState)
* @throws E any {@link Exception} raised by the {@link RecoveryCallback} upon
<T, E extends Throwable> T execute(RetryCallback<T, E> retryCallback, RecoveryCallback<T> recoveryCallback,
RetryState retryState) throws E;
}
下面主要介绍一下RetryTemplate配置的时候，需要设置的重试策略和退避策略
RetryPolicy
RetryPolicy是一个接口, 然后有很多具体的实现，我们先来看看它的接口中定义了什么方法
package org.springframework.retry;
import java.io.Serializable;
/**
* A {@link RetryPolicy} is responsible for allocating and managing resources needed by
* {@link RetryOperations}. The {@link RetryPolicy} allows retry operations to be aware of
* their context. Context can be internal to the retry framework, e.g. to support nested
* retries. Context can also be external, and the {@link RetryPolicy} provides a uniform
* API for a range of different platforms for the external context.
*
* @author Dave Syer
*/
public interface RetryPolicy extends Serializable {
/**
* @param context the current retry status
* @return true if the operation can proceed
*/
boolean canRetry(RetryContext context);
* Acquire resources needed for the retry operation. The callback is passed in so that
* marker interfaces can be used and a manager can collaborate with the callback to
* set up some state in the status token.
* @param parent the parent context if we are in a nested retry.
* @return a {@link RetryContext} object specific to this policy.
*
RetryContext open(RetryContext parent);
* @param context a retry status created by the {@link #open(RetryContext)} method of
* this policy.
void close(RetryContext context);
* Called once per retry attempt, after the callback fails.
* @param context the current status object.
* @param throwable the exception to throw
void registerThrowable(RetryContext context, Throwable throwable);
}
我们来看看他有什么具体的实现类
- SimpleRetryPolicy 默认最多重试3次
- TimeoutRetryPolicy 默认在1秒内失败都会重试
- ExpressionRetryPolicy 符合表达式就会重试
- CircuitBreakerRetryPolicy 增加了熔断的机制，如果不在熔断状态，则允许重试
- CompositeRetryPolicy 可以组合多个重试策略
- NeverRetryPolicy 从不重试（也是一种重试策略哈）
- AlwaysRetryPolicy 总是重试
- 等等...
BackOffPolicy
看一下退避策略，退避是指怎么去做下一次的重试，在这里其实就是等待多长时间。
- FixedBackOffPolicy 默认固定延迟1秒后执行下一次重试
- ExponentialBackOffPolicy 指数递增延迟执行重试，默认初始0.1秒，系数是2，那么下次延迟0.2秒，再下次就是延迟0.4秒，如此类推，最大30秒。
- ExponentialRandomBackOffPolicy 在上面那个策略上增加随机性
- UniformRandomBackOffPolicy 这个跟上面的区别就是，上面的延迟会不停递增，这个只会在固定的区间随机
- StatelessBackOffPolicy 这个说明是无状态的，所谓无状态就是对上次的退避无感知，从它下面的子类也能看出来
- 等等...
RetryListener
listener可以监听重试，并执行对应的回调方法
package org.springframework.retry;
/**
* Interface for listener that can be used to add behaviour to a retry. Implementations of
* {@link RetryOperations} can chose to issue callbacks to an interceptor during the retry
* lifecycle.
*
* @author Dave Syer
*/
public interface RetryListener {
/**
* Called before the first attempt in a retry. For instance, implementers can set up
* state that is needed by the policies in the {@link RetryOperations}. The whole
* retry can be vetoed by returning false from this method, in which case a
* {@link TerminatedRetryException} will be thrown.
* @param <T> the type of object returned by the callback
* @param <E> the type of exception it declares may be thrown
* @param context the current {@link RetryContext}.
* @param callback the current {@link RetryCallback}.
* @return true if the retry should proceed.
*/
<T, E extends Throwable> boolean open(RetryContext context, RetryCallback<T, E> callback);
* Called after the final attempt (successful or not). Allow the interceptor to clean
* up any resource it is holding before control returns to the retry caller.
* @param throwable the last exception that was thrown by the callback.
* @param <E> the exception type
* @param <T> the return value
<T, E extends Throwable> void close(RetryContext context, RetryCallback<T, E> callback, Throwable throwable);
* Called after every unsuccessful attempt at a retry.
* @param <E> the exception to throw
<T, E extends Throwable> void onError(RetryContext context, RetryCallback<T, E> callback, Throwable throwable);
}
使用如下：
自定义一个Listener
package org.example;
import lombok.extern.slf4j.Slf4j;
import org.springframework.retry.RetryCallback;
import org.springframework.retry.RetryContext;
import org.springframework.retry.listener.RetryListenerSupport;
@Slf4j
public class DefaultListenerSupport extends RetryListenerSupport {
@Override
public <T, E extends Throwable> void close(RetryContext context,
RetryCallback<T, E> callback, Throwable throwable) {
log.info("onClose");
super.close(context, callback, throwable);
}
public <T, E extends Throwable> void onError(RetryContext context,
RetryCallback<T, E> callback, Throwable throwable) {
log.info("onError");
super.onError(context, callback, throwable);
public <T, E extends Throwable> boolean open(RetryContext context,
RetryCallback<T, E> callback) {
log.info("onOpen");
return super.open(context, callback);
}
把listener设置到retryTemplate中
package org.example;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.retry.backoff.FixedBackOffPolicy;
import org.springframework.retry.policy.SimpleRetryPolicy;
import org.springframework.retry.support.RetryTemplate;
@Configuration
@Slf4j
public class AppConfig {
@Bean
public RetryTemplate retryTemplate() {
RetryTemplate retryTemplate = new RetryTemplate();
SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy(); //设置重试策略
retryPolicy.setMaxAttempts(2);
retryTemplate.setRetryPolicy(retryPolicy);
FixedBackOffPolicy fixedBackOffPolicy = new FixedBackOffPolicy(); //设置退避策略
fixedBackOffPolicy.setBackOffPeriod(2000L);
retryTemplate.setBackOffPolicy(fixedBackOffPolicy);
retryTemplate.registerListener(new DefaultListenerSupport()); //设置retryListener
return retryTemplate;
}
}
测试结果：
2021-01-08 10:48:05.663 INFO 20956 --- [ main] org.example.DefaultListenerSupport : onOpen
2021-01-08 10:48:05.663 INFO 20956 --- [ main] org.example.RetryTemplateService : do something...
2021-01-08 10:48:05.663 INFO 20956 --- [ main] org.example.DefaultListenerSupport : onError
2021-01-08 10:48:07.664 INFO 20956 --- [ main] org.example.RetryTemplateService : do something...
2021-01-08 10:48:07.664 INFO 20956 --- [ main] org.example.DefaultListenerSupport : onError
2021-01-08 10:48:07.664 INFO 20956 --- [ main] org.example.RetryTemplateTest : RecoveryCallback....
2021-01-08 10:48:07.664 INFO 20956 --- [ main] org.example.DefaultListenerSupport : onClose
参考
usage-of-exceptionexpression-in-spring-retry
到此这篇关于Spring Boot中使用Spring-Retry重试框架的文章就介绍到这了,更多相关Spring Boot使用Spring-Retry内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！
相关推荐
-
springboot整合spring-retry的实现示例
1.背景 本系统调用外围系统接口(http+json),但是发现有时外围系统服务不太稳定,有时候会出现返回一串xml或者gateway bad的信息,导致调用失败,基于这一原因,采用基于springboot,整合spring-retry的重试机制到系统工程中,demo已经放到github上. 2.解决方案 简要说明:demo工程基于springboot,为了方便验证,采用swagger进行测试验证. 2.1 pom文件 <?xml version="1.0" encoding=&
-
Spring boot使用spring retry重试机制的方法示例
当我们调用接口的时候由于网络原因可能失败,再尝试就成功了,这就是重试机制.非幂等的情况下要小心使用重试. tips:幂等性 HTTP/1.1中对幂等性的定义是:一次和多次请求某一个资源对于资源本身应该具有同样的结果(网络超时等问题除外).也就是说,其任意多次执行对资源本身所产生的影响均与一次执行的影响相同. 注解方式使用Spring Retry (一)Maven依赖 <!-- 重试机制 --> <dependency> <groupId>org.springframew
-
SpringBoot整合spring-retry实现接口请求重试机制及注意事项
目录 一.重试机制 二.重试机制要素 三.重试机制注意事项 四.SpringBoot整合spring-retry 1)添加依赖 2)添加@EnableRetry注解 3)添加@Retryable注解 4)Controller测试代码 5)发送请求 6)补充:@Recover 一.重试机制 由于网络不稳定或网络抖动经常会造成接口请求失败的情况,当我们再去尝试就成功了,这就是重试机制. 其主要目的就是要尽可能地提高请求成功的概率,但一般情况下,我们请求第一次失败,代码运行就抛出异常结束了,如果想再次
-
Springboot Retry组件@Recover失效问题解决方法
目录 背景 问题复现 问题解决 背景 在使用springboot的retry模块时,你是否出现过@Recover注解失效的问题呢?下面我会对该问题进行复现,并且简要的说下解决方法. 问题复现 首先我们引入maven <dependency> <groupId>org.springframework.retry</groupId> <artifactId>spring-retry</artifactId> </dependency> &
-
详解spring boot使用@Retryable来进行重处理
前言 什么时候需要重处理? 在实际工作中,重处理是一个非常常见的场景,比如:发送消息失败,调用远程服务失败,争抢锁失败,等等,这些错误可能是因为网络波动造成的,等待过后重处理就能成功.通常来说,会用try/catch,while循环之类的语法来进行重处理,但是这样的做法缺乏统一性,并且不是很方便,要多写很多代码.然而spring-retry却可以通过注解,在不入侵原有业务逻辑代码的方式下,优雅的实现重处理功能. 思路 使用@Retryable和@Recover实现重处理,以及重处理失后的回调 实
-
SpringBoot @Retryable注解方式
背景 在调用第三方接口或者使用MQ时,会出现网络抖动,连接超时等网络异常,所以需要重试.为了使处理更加健壮并且不太容易出现故障,后续的尝试操作,有时候会帮助失败的操作最后执行成功.一般情况下,需要我们自行实现重试机制,一般是在业务代码中加入一层循环,如果失败后,再尝试重试,但是这样实现并不优雅.在SpringBoot中,已经实现了相关的能力,通过@Retryable注解可以实现我们想要的结果. @Retryable 首先来看一下Spring官方文档的解释: @Retryable注解可以注解于方法
-
Spring Boot中使用 Spring Security 构建权限系统的示例代码
Spring Security是一个能够为基于Spring的企业应用系统提供声明式的安全访问控制解决方案的安全框架.它提供了一组可以在Spring应用上下文中配置的Bean,为应用系统提供声明式的安全访问控制功能,减少了为企业系统安全控制编写大量重复代码的工作. 权限控制是非常常见的功能,在各种后台管理里权限控制更是重中之重.在Spring Boot中使用 Spring Security 构建权限系统是非常轻松和简单的.下面我们就来快速入门 Spring Security .在开始前我们需要一对
-
Spring Boot中使用Spring Retry重试框架的操作方法
目录 Spring Retry 在SpringBoot 中的应用 Maven依赖 注解使用 开启Retry功能 注解@Retryable 注解@Recover 注解@CircuitBreaker RetryTemplate RetryTemplate配置 使用RetryTemplate RetryPolicy BackOffPolicy RetryListener 参考 Spring Retry 在SpringBoot 中的应用 Spring Retry提供了自动重新调用失败的操作的功能.这在错
-
Spring Boot中整合Spring Security并自定义验证代码实例
最终效果 1.实现页面访问权限限制 2.用户角色区分,并按照角色区分页面权限 3.实现在数据库中存储用户信息以及角色信息 4.自定义验证代码 效果如下: 1.免验证页面 2.登陆页面 在用户未登录时,访问任意有权限要求的页面都会自动跳转到登陆页面. 3.需登陆才能查看的页面 用户登陆后,可以正常访问页面资源,同时可以正确显示用户登录名: 4.用户有角色区分,可以指定部分页面只允许有相应用户角色的人使用 4.1.只有ADMIN觉得用户才能查看的页面(权限不足) 4.2.只有ADMIN觉得用户才能查
-
详解如何在spring boot中使用spring security防止CSRF攻击
CSRF是什么? CSRF(Cross-site request forgery),中文名称:跨站请求伪造,也被称为:one click attack/session riding,缩写为:CSRF/XSRF. CSRF可以做什么? 你这可以这么理解CSRF攻击:攻击者盗用了你的身份,以你的名义发送恶意请求.CSRF能够做的事情包括:以你名义发送邮件,发消息,盗取你的账号,甚至于购买商品,虚拟货币转账......造成的问题包括:个人隐私泄露以及财产安全. CSRF漏洞现状 CSRF这种攻击方式
-
Spring Security 在 Spring Boot 中的使用详解【集中式】
1.1 准备 1.1.1 创建 Spring Boot 项目 创建好一个空的 Spring Boot 项目之后,写一个 controller 验证此时是可以直接访问到该控制器的. 1.1.2 引入 Spring Security 在 Spring Boot 中引入 Spring Security 是相当简单的,可以在用脚手架创建项目的时候勾选,也可以创建完毕后在 pom 文件中加入相关依赖. <dependency> <groupId>org.springframework
-
在Spring Boot中加载初始化数据的实现
在Spring Boot中,Spring Boot会自动搜索映射的Entity,并且创建相应的table,但是有时候我们希望自定义某些内容,这时候我们就需要使用到data.sql和schema.sql. 依赖条件 Spring Boot的依赖我们就不将了,因为本例将会有数据库的操作,我们这里使用H2内存数据库方便测试: <dependency> <groupId>com.h2database</groupId> <artifactId>h2</arti
-
Spring Boot中使用Spring-Retry重试框架的实现
目录 Maven依赖 注解使用 开启Retry功能 注解@Retryable 注解@Recover 注解@CircuitBreaker RetryTemplate RetryTemplate配置 使用RetryTemplate RetryPolicy BackOffPolicy RetryListener 参考 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
-
Spring Retry重试框架的使用讲解
目录 命令式 声明式(注解方式) 1. 用法 2. RetryTemplate 3. RecoveryCallback 4. Listeners 5. 声明式重试 重试的使用场景比较多,比如调用远程服务时,由于网络或者服务端响应慢导致调用超时,此时可以多重试几次.用定时任务也可以实现重试的效果,但比较麻烦,用Spring Retry的话一个注解搞定所有.话不多说,先看演示. 首先引入依赖 <dependency> <groupId>org.springframework.retry
-
Spring Boot中使用Spring-data-jpa实现数据库增删查改
在实际开发过程中,对数据库的操作无非就"增删改查".就最为普遍的单表操作而言,除了表和字段不同外,语句都是类似的,开发人员需要写大量类似而枯燥的语句来完成业务逻辑. 为了解决这些大量枯燥的数据操作语句,我们第一个想到的是使用ORM框架,比如:Hibernate.通过整合Hibernate之后,我们以操作Java实体的方式最终将数据改变映射到数据库表中. 为了解决抽象各个Java实体基本的"增删改查"操作,我们通常会以泛型的方式封装一个模板Dao来进行抽象简化,但是这
-
详解在spring boot中配置多个DispatcherServlet
spring boot为我们自动配置了一个开箱即用的DispatcherServlet,映射路径为'/',但是如果项目中有多个服务,为了对不同服务进行不同的配置管理,需要对不同服务设置不同的上下文,比如开启一个DispatcherServlet专门用于rest服务. 传统springMVC项目 在传统的springMVC项目中,配置多个DispatcherServlet很轻松,在web.xml中直接配置多个就行: <servlet> <servlet-name>restServle