@Retryable – Spring Retry

Spring Retry is a module in the Spring Framework that provides a declarative way to add retry logic to methods. It allows you to easily retry a method call in case of a specific exception or a set of exceptions. The @Retryable annotation is a key component of Spring Retry, and it is used to mark a method as retryable.

Here’s an example of how to use @Retryable in a Spring Boot application:

First, you need to include the Spring Retry dependency in your pom.xml or build.gradle:

<!-- Maven -->
<dependency>
    <groupId>org.springframework.retry</groupId>
    <artifactId>spring-retry</artifactId>
    <version>1.3.1</version>
</dependency>

Next, you need to enable Spring Retry in your Spring Boot application by adding the @EnableRetry annotation to your configuration class:

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.retry.annotation.EnableRetry;

@SpringBootApplication
@EnableRetry
public class MyApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }
}

Now, you can use the @Retryable annotation on a method that you want to retry in case of a specific exception. Here’s an example:

import org.springframework.retry.annotation.Retryable;

@Service
public class MyService {

    private int retryCounter = 0;

    @Retryable(value = { MyCustomException.class }, maxAttempts = 3)
    public void retryMethod() throws MyCustomException {
        retryCounter++;
        System.out.println("Retry attempt #" + retryCounter);
        if (retryCounter < 3) {
            throw new MyCustomException("Simulating a retryable exception.");
        }
    }
}

In this example:

The @Retryable annotation is applied to the retryMethod in the MyService class.
We specify MyCustomException.class as the exception to trigger a retry.
maxAttempts indicates the maximum number of retry attempts (in this case, 3).

Now, when you call the retryMethod() and a MyCustomException is thrown, Spring Retry will automatically retry the method up to three times.

To test your retryable method, you can create a controller or any other component to trigger it:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MyController {

    @Autowired
    private MyService myService;

    @GetMapping("/triggerRetry")
    public String triggerRetry() {
        try {
            myService.retryMethod();
            return "Method executed successfully.";
        } catch (MyCustomException e) {
            return "Method failed after retry attempts.";
        }
    }
}

Now, when you access the /triggerRetry endpoint, it will trigger the retryMethod, and it will retry up to three times if a MyCustomException is thrown.

Remember to replace MyCustomException with your specific exception class that you want to retry. You can customize the retry behavior by adjusting the @Retryable annotation’s parameters to fit your use case.

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