1: POM configuration
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.3</version>
<!-- <version>2.3.5.RELEASE</version>-->
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.mail</groupId>
<artifactId>elegant</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>elegant</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.retry</groupId>
<artifactId>spring-retry</artifactId>
<version>1.3.4</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId >
<artifactId>aspectjweaver</artifactId >
<!-- <version>1.6.11</version >-->
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2: yml configuration
server:
port: 8080
servlet:
context-path: /
3: Start class
@EnableRetry
@SpringBootApplication
public class ReTryDemoApplication {
public static void main(String[] args) {
SpringApplication.run(ReTryDemoApplication.class, args);
}
}
4：controller
@RestController
public class TestController {
@Autowired
TestRetryService testRetryServiceImpl;
@GetMapping("/testRetry")
public String testRetry() throws Exception {
int code=0;
int result = testRetryServiceImpl.dignifiedTest(code);
return "result："+result;
}
}
5：service
public interface TestRetryService {
int dignifiedTest(int code) throws Exception;
}
6：serviceImpl
@Service
public class TestRetryServiceImpl implements TestRetryService {
@Override
@Retryable(value = Exception.class,maxAttempts = 3,backoff = @Backoff(delay = 2000,multiplier = 1.5))
public int dignifiedTest(int code) throws Exception{
System.out.println("dignifiedTest被调用,时间："+ LocalTime.now());
if (code==0){
throw new Exception("情况不对头！");
}
System.out.println("dignifiedTest被调用,情况对头了！");
return 200;
}
@Recover
public int recover(Exception e){
System.out.println("回调方法执行！！！！");
//记日志到数据库 或者调用其余的方法
return 400;
}
}
@Retryable: Annotation method to mark that the current method will use the retry mechanism.
Value inside: The retry trigger mechanism, which is triggered when an Exception is encountered;
maxAttempts: The number of retries (including the first call, that is, if Set 3 times, after calling once, if it keeps failing to trigger retry, then the current method will be called twice);
delay: the delay time of retry, that is, the interval from the last retry method call, in milliseconds
multiplier: The multiple of the delay interval, that is, if the first retry interval is 2000ms, then the second retry is 2000ms multiplied by this multiple of 1.5, which is 3000ms; maxDelay: the maximum time interval between
retries , the default is 0, that is, ignored, if it is less than the delay setting, the default is 30000L
@Recover, that is, mark the current method as a callback method with annotations, you can see that Exception e is written in the passed parameter, which is used as a callback Connector code (if the number of retries is exhausted and still fails, we throw this Exception e notification to trigger this callback method)
PS: This callback method and the retry method are written in the same implementation class.