springboot(十四)使用spring retry

古城微笑少年丶 2022-06-17 02:55 107阅读 0赞

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。

1、引入jar包

<dependency>
    			<groupId>org.springframework.retry</groupId>
    			<artifactId>spring-retry</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.aspectj</groupId>
    			<artifactId>aspectjweaver</artifactId>
    		</dependency>

2、模拟网络异常，创建一个异常

package com.demo.exception;
    
    import lombok.Builder;
    import lombok.Getter;
    
    /**
     * Created by huguoju on 2017/4/13.
     */
    @Builder
    @Getter
    public class RetryException extends RuntimeException {
        private String code;
        private String message;
    }

3、在Application上添加@EnableRetry开启Retry服务

@EnableRetry
    public class SpringbootApplication {

4、在service模拟访问异常，抛出异常

package com.demo.service.impl;
    
    import com.demo.exception.RetryException;
    import com.demo.service.RetryService;
    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;
    
    /**
     * Created by huguoju on 2017/4/13.
     */
    @Service("retryService")
    @Slf4j
    public class RetryServiceImpl implements RetryService {
        int i=1;
        @Override
        @Retryable(value = {RuntimeException.class},maxAttempts = 4,backoff = @Backoff(delay = 1000l,multiplier = 1))
        public String retry() {
            log.info("测试retry");
            i++;//生产环境此处应该为调用第三方接口，判断接口返回code
            if(i==3){
                return i+"";
            }
            RetryException retryException=RetryException.builder().code("9999").message("连接超时").build();
            throw retryException;
        }
    
     
        @Recover
        public String recover(RetryException e){
            log.info(e.getMessage());
            return "6";
        }
    }

说明：

@Retryable：标注此注解的方法在发生异常时会进行重试 参数说明：value：抛出指定异常才会重试           include：和value一样，默认为空，当exclude也为空时，默认所以异常           exclude：指定不处理的异常           maxAttempts:最大重试次数，默认3次           backoff：重试等待策略，默认使用@Backoff，@Backoff的value默认为1000L，multiplier（指定延迟倍数）                    默认为0，表示固定暂停1秒后进行重试，如果把multiplier设置为2，则第一次重试为1秒，第二次为                    2秒，第三次为4秒 @Recover：用于@Retryable重试失败后处理方法，此方法里的异常一定要是@Retryable方法里抛出的异常，否则不会调用           这个方法 
     
     
     5、在其他service里调用上面的service抛出异常    @Override
        public Map testRetry() {
            Map map= Maps.newHashMap();
            String s=retryService.retry();
            if (s.equals("3")){
                log.info("成功啦啦啦啦啦啦啦啦");
            }else {
                log.info("失败了");
            }
            map.put("result",s);
            return map;
        }
     6、定义测试controller package com.demo.controller;
    
    import com.demo.service.RetryService;
    import com.demo.service.TestService;
    import com.google.common.collect.Maps;
    import io.swagger.annotations.Api;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.http.MediaType;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.Map;
    
    /**
     * Created by huguoju on 2017/4/13.
     */
    @RestController
    @RequestMapping("retry")
    @Api(value = "重试机制",tags = "重试机制")
    public class RetryController {
        @Autowired
        public TestService testService;
        @RequestMapping(value = "testRetry",method = {RequestMethod.POST,RequestMethod.GET},produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
        public Map testRetry(){
            Map map=Maps.newHashMap();
            try {
                map= testService.testRetry();
                return map;
            }catch (Exception e){
                e.printStackTrace();
                return map;
            }
        }
    }
    
    访问controller，看日志输出 15:21:30 WARN  [qtp1129243682-21]  com.atomikos.icatch.imp.TransactionServiceImp - Attempt to create a transaction with a timeout that exceeds com.atomikos.icatch.max_timeout - truncating to: 300000
    15:21:30 INFO  [qtp1129243682-21]  com.atomikos.icatch.imp.BaseTransactionManager - createCompositeTransaction ( 10000000 ): created new ROOT transaction with id 10.3.5.31.tm0000100002
    15:21:30 INFO  [qtp1129243682-21]  com.demo.service.impl.RetryServiceImpl - 测试retry
    15:21:31 INFO  [qtp1129243682-21]  com.demo.service.impl.RetryServiceImpl - 测试retry
    15:21:31 INFO  [qtp1129243682-21]  com.demo.service.impl.TestServiceImpl - 成功啦啦啦啦啦啦啦啦
    15:21:31 INFO  [qtp1129243682-21]  com.atomikos.icatch.imp.CompositeTransactionImp - commit() done (by application) of transaction 10.3.5.31.tm0000100002
    要测试@Recover，即一直异常，只需要把RetryServiceImpl里的if(i==3)改为if(i==6),把调用service里if(s.equals("3"))改完if(s.equals("6)),然后重新访问，日志： 15:26:54 WARN  [qtp1870436181-20]  com.atomikos.icatch.imp.TransactionServiceImp - Attempt to create a transaction with a timeout that exceeds com.atomikos.icatch.max_timeout - truncating to: 300000
    15:26:54 INFO  [qtp1870436181-20]  com.atomikos.icatch.imp.BaseTransactionManager - createCompositeTransaction ( 10000000 ): created new ROOT transaction with id 10.3.5.31.tm0000100003
    15:26:54 INFO  [qtp1870436181-20]  com.demo.service.impl.RetryServiceImpl - 测试retry
    15:26:55 INFO  [qtp1870436181-20]  com.demo.service.impl.RetryServiceImpl - 测试retry
    15:26:56 INFO  [qtp1870436181-20]  com.demo.service.impl.RetryServiceImpl - 测试retry
    15:26:57 INFO  [qtp1870436181-20]  com.demo.service.impl.RetryServiceImpl - 测试retry
    15:26:57 INFO  [qtp1870436181-20]  com.demo.service.impl.RetryServiceImpl - 连接超时
    15:26:57 INFO  [qtp1870436181-20]  com.demo.service.impl.TestServiceImpl - 成功啦啦啦啦啦啦啦啦
    15:26:57 INFO  [qtp1870436181-20]  com.atomikos.icatch.imp.CompositeTransactionImp - commit() done (by application) of transaction 10.3.5.31.tm0000100003