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首先,添加依赖配置:

   	
    
     org.springframework.boot
    	
    
     spring-boot-starter-aop
    
   
   	
    
     org.springframework.retry
    	
    
     spring-retry
    
   

其次,再Application.java类上使用注解@EnableRetry启动重试机制

@EnableRetrypublic class Application {       public static void main(String[] args) {           SpringApplication.run(Application.class,args);    }}

最后,使用注解@Retryable实现重试机制:

创建RetryableService.java类

@Servicepublic class RetryableService{           /**     * @param name 模拟异常标志     */    @Retryable(value = Exception.class, maxAttempts = 6, backoff = @Backoff(value = 1000))    public void doWork(String name) {           System.out.println("===========do work" + name + "==============");        if ("3".equals(name)) {               System.out.println("模拟异常...");            throw new RuntimeException("work error");        }    }}

单元测试：

@RunWith(SpringRunner.class)@SpringBootTest(classes = Application.class)@WebAppConfigurationpublic class Test {       @Autowired    private RetryableService retryableService;    @org.junit.Test    public void retryableTest(){           for (int i = 0; i < 5; i++) {               retryableService.doWork(String.valueOf(i));        }    }}

程序输出：

===========do work0=========================do work1=========================do work2=========================do work3==============模拟异常...===========do work3==============模拟异常...===========do work3==============模拟异常...===========do work3==============模拟异常...===========do work3==============模拟异常...===========do work3==============模拟异常...java.lang.RuntimeException: work error

注解@Retryable属性说明：

• value：抛出指定异常才会重试
• maxAttempts：最大重试次数，默认为3次
• include：和value一样，默认为空，当exclude也为空时，所有异常都需要重试
• exclude：指定不处理的异常，默认为空，当include也为空时，所有异常都需要重试
• backoff：重试等待策略，默认使用@Backoff，@Backoff的value默认为1000L

注解@Backoff属性说明：

• value：隔多少毫秒后再次重试，默认为1000L
• delay：同value一样，默认为0
• multiplier：指定延迟倍数，默认为0，如果delay=2000L，multiplier=2，则第一次重试为2秒，第二次为4秒，第三次为8秒……

注解@Recover说明：

  注解@Retryable重试还是失败后的回调处理.

注解@Retryable代码实现：

@Servicepublic class RetryableService{       /**     * @param name 模拟异常标志     */    @Retryable(value = Exception.class, maxAttempts = 6, backoff = @Backoff(value = 1000))    public void doWork(String name) {           System.out.println("===========do work" + name + "==============");        if ("3".equals(name)) {               System.out.println("模拟异常...");            throw new RuntimeException("work error");        }    }    /**     * 重试失败后的回调处理     * @param e     */    @Recover    public void doWorkRecover(Exception e){           System.out.println("doWorkRecover = " + e.getMessage());    }}

程序输出：

===========do work0=========================do work1=========================do work2=========================do work3==============模拟异常...===========do work3==============模拟异常...===========do work3==============模拟异常...===========do work3==============模拟异常...===========do work3==============模拟异常...===========do work3==============模拟异常...doWorkRecover = work error===========do work4==============

⚠️注意：在使用@Recover和@Retryable时，要在spring容器中管理的bean里面使用，例如下面这种场景不会生效。

@Servicepublic class RetryableService{       public void doWork1(String name){           doWork(name);    }    /**     * @param name 模拟异常标志     */    @Retryable(value = Exception.class, maxAttempts = 6, backoff = @Backoff(value = 1000))    public void doWork(String name) {           System.out.println("===========do work" + name + "==============");        if ("3".equals(name)) {               System.out.println("模拟异常...");            throw new RuntimeException("work error");        }    }    /**     * 重试失败后的回调处理     * @param e     */    @Recover    public void doWorkRecover(Exception e){           System.out.println("doWorkRecover = " + e.getMessage());        throw new RuntimeException("doWorkRecover error");    }}

@RunWith(SpringRunner.class)@SpringBootTest(classes = Application.class)@WebAppConfigurationpublic class Test {       @Autowired    private RetryableService retryableService;    @org.junit.Test    public void retryableTest(){           for (int i = 0; i < 5; i++) {               retryableService.doWork1(String.valueOf(i));        }    }}

程序输出：

===========do work0=========================do work1=========================do work2=========================do work3==============模拟异常...java.lang.RuntimeException: work error

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