本文介紹了Spring重試支持Spring Retry的方法,分享給大家,具體如下:
第一步、引入maven依賴
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.3.RELEASE</version></parent><dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId></dependency><!-- https://mvnrepository.com/artifact/org.springframework.retry/spring-retry --><dependency> <groupId>org.springframework.retry</groupId> <artifactId>spring-retry</artifactId> <version>1.1.2.RELEASE</version></dependency><dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.6</version></dependency>
第二步、添加@Retryable和@Recover註解
package hello;import org.springframework.remoting.RemoteAccessException;import org.springframework.retry.annotation.Backoff;import org.springframework.retry.annotation.Recover;import org.springframework.retry.annotation.Retryable;import org.springframework.stereotype.Service;@Servicepublic class RemoteService {@Retryable(value= {RemoteAccessException.class},maxAttempts = 3,backoff = @Backoff(delay = 5000l,multiplier = 1))public void call() throws Exception { System.out.println("do something..."); throw new RemoteAccessException("RPC調用異常");}@Recoverpublic void recover(RemoteAccessException e) { System.out.println(e.getMessage());}} @Retryable註解<br />被註解的方法發生異常時會重試
value:指定發生的異常進行重試
include:和value一樣,默認空,當exclude也為空時,所有異常都重試
exclude:指定異常不重試,默認空,當include也為空時,所有異常都重試
maxAttemps:重試次數,默認3
backoff:重試補償機制,默認沒有
@Backoff註解
delay:指定延遲後重試
multiplier:指定延遲的倍數,比如delay=5000l,multiplier=2時,第一次重試為5秒後,第二次為10秒,第三次為20秒
@Recover
當重試到達指定次數時,被註解的方法將被回調,可以在該方法中進行日誌處理。需要注意的是發生的異常和入參類型一致時才會回調
第三步、SpringBoot方式啟動容器、測試
添加@EnableRetry註解,啟用重試功能
package hello;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.ApplicationContext;import org.springframework.context.annotation.AnnotationConfigApplicationContext;import org.springframework.retry.annotation.EnableRetry;@SpringBootApplication@EnableRetrypublic class Application { public static void main(String[] args) throws Exception { ApplicationContext annotationContext = new AnnotationConfigApplicationContext("hello"); RemoteService remoteService = annotationContext.getBean("remoteService", RemoteService.class); remoteService.call(); }}運行結果:
16:50:51.012 [main] DEBUG org.springframework.retry.support.RetryTemplate - Retry: count=0
do something…
16:50:51.025 [main] DEBUG org.springframework.retry.backoff.ExponentialBackOffPolicy - Sleeping for 5000
16:50:56.026 [main] DEBUG org.springframework.retry.support.RetryTemplate - Checking for rethrow: count=1
16:50:56.026 [main] DEBUG org.springframework.retry.support.RetryTemplate - Retry: count=1
do something…
16:50:56.026 [main] DEBUG org.springframework.retry.backoff.ExponentialBackOffPolicy - Sleeping for 5000
16:51:01.026 [main] DEBUG org.springframework.retry.support.RetryTemplate - Checking for rethrow: count=2
16:51:01.027 [main] DEBUG org.springframework.retry.support.RetryTemplate - Retry: count=2
do something…
16:51:01.027 [main] DEBUG org.springframework.retry.support.RetryTemplate - Checking for rethrow: count=3
16:51:01.027 [main] DEBUG org.springframework.retry.support.RetryTemplate - Retry failed last attempt: count=3
RPC調用異常
參考:https://github.com/spring-projects/spring-retry
補充
對於非冪等的請求(比如新增,更新操作),千萬不要使用重試,對數據一致性會造成很大影響。
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持武林網。