SpringRetry重試框架的具體使用

<!-- SpringRetry -->
<dependency>
   <groupId>org.springframework.retry</groupId>
   <artifactId>spring-retry</artifactId>
</dependency>
<dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-aspects</artifactId>
</dependency>

package org.springframework.retry;

public interface RetryListener {

 /**
  * 任務開始執行時調用，隻調用一次
  */
 <T, E extends Throwable> boolean open(RetryContext context, RetryCallback<T, E> callback);

 /**
  * 任務執行結束時(包含重試)調用，隻調用一次
  */
 <T, E extends Throwable> void close(RetryContext context, RetryCallback<T, E> callback, Throwable throwable);

 /**
  * 出現錯誤時回調
  */
 <T, E extends Throwable> void onError(RetryContext context, RetryCallback<T, E> callback, Throwable throwable);
}

FixedBackOffPolicy fixedBackOffPolicy = new FixedBackOffPolicy();
fixedBackOffPolicy.setBackOffPeriod(1000L);
retryTemplate.setBackOffPolicy(fixedBackOffPolicy);

// 指數回退(秒)，第一次回退1s，第二次回退2s，第三次4秒，第四次8秒
ExponentialBackOffPolicy exponentialBackOffPolicy = new ExponentialBackOffPolicy();
exponentialBackOffPolicy.setInitialInterval(1000L);
exponentialBackOffPolicy.setMultiplier(2);
retryTemplate.setBackOffPolicy(exponentialBackOffPolicy);

// 重試策略
SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy();
retryPolicy.setMaxAttempts(5);
retryTemplate.setRetryPolicy(retryPolicy);

public final <T, E extends Throwable> T execute(RetryCallback<T, E> retryCallback) throws E

import com.codecoord.util.PrintUtil;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.retry.RetryCallback;
import org.springframework.retry.RetryContext;
import org.springframework.retry.RetryListener;
import org.springframework.retry.backoff.ExponentialBackOffPolicy;
import org.springframework.retry.policy.SimpleRetryPolicy;
import org.springframework.retry.support.RetryTemplate;

@Configuration
public class RetryTemplateConfig {

    /**
     * 註入retryTemplate
     */
    @Bean
    public RetryTemplate retryTemplate() {
        RetryTemplate retryTemplate = new RetryTemplate();

        /// 回退固定時間(秒)
       /* FixedBackOffPolicy fixedBackOffPolicy = new FixedBackOffPolicy();
        fixedBackOffPolicy.setBackOffPeriod(1000L);
        retryTemplate.setBackOffPolicy(fixedBackOffPolicy);*/

        // 指數回退(秒)，第一次回退1s，第二次回退2s
        ExponentialBackOffPolicy exponentialBackOffPolicy = new ExponentialBackOffPolicy();
        exponentialBackOffPolicy.setInitialInterval(1000L);
        exponentialBackOffPolicy.setMultiplier(2);
        retryTemplate.setBackOffPolicy(exponentialBackOffPolicy);

        // 重試策略
        SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy();
        retryPolicy.setMaxAttempts(5);
        retryTemplate.setRetryPolicy(retryPolicy);

        // 設置監聽器，open和close分別在啟動和結束時執行一次
        RetryListener[] listeners = {
                new RetryListener() {
                    @Override
                    public <T, E extends Throwable> boolean open(RetryContext context, RetryCallback<T, E> callback) {
                        PrintUtil.print("open");
                        return true;
                    }
                    @Override
                    public <T, E extends Throwable> void close(RetryContext context, RetryCallback<T, E> callback,
                            Throwable throwable) {
                        PrintUtil.print("close");
                    }
                    @Override
                    public <T, E extends Throwable> void onError(RetryContext context, RetryCallback<T, E> callback,
                            Throwable throwable) {
                        PrintUtil.print("onError");
                    }
                }
        };
        retryTemplate.setListeners(listeners);

        return retryTemplate;
    }
}

@RestController
public class SpringRetryController {
    @Resource
    private RetryTemplate retryTemplate;
    private static int count = 0;

    @RequestMapping("/retry")
    public Object retry() {
        try {
            count = 0;
            retryTemplate.execute((RetryCallback<Void, RuntimeException>) context -> {
                // 業務代碼
                // ....
                // 模擬拋出異常
                ++count;
                throw new RuntimeException("拋出異常");
            });
        } catch (RuntimeException e) {
            System.out.println("Exception");
        }

        return "retry = " + count;
    }
}

import org.springframework.retry.annotation.Retryable;

public interface RetryService {

    /**
     * 重試方法調用
     */
    @Retryable
    void retryServiceCall();
}

import org.springframework.retry.annotation.EnableRetry;
import org.springframework.stereotype.Service;

@EnableRetry
@Service
public class RetryServiceImpl implements RetryService {

    @Override
    public void retryServiceCall() {
        PrintUtil.print("方法調用..");
        throw new RuntimeException("手工異常");
    }
}

@RequestMapping("/retryAnnotation")
public Object retryAnnotation() {
    retryService.retryServiceCall();
    return "retryAnnotation";
}

@Target({ ElementType.METHOD, ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Retryable {

 /**
  * Retry interceptor bean name to be applied for retryable method. Is mutually
  * exclusive with other attributes.
  * @return the retry interceptor bean name
  */
 String interceptor() default "";

 /**
  * Exception types that are retryable. Synonym for includes(). Defaults to empty (and
  * if excludes is also empty all exceptions are retried).
  * @return exception types to retry
  */
 Class<? extends Throwable>[] value() default {};

 /**
  * Exception types that are retryable. Defaults to empty (and if excludes is also
  * empty all exceptions are retried).
  * @return exception types to retry
  */
 Class<? extends Throwable>[] include() default {};

 /**
  * Exception types that are not retryable. Defaults to empty (and if includes is also
  * empty all exceptions are retried).
  * If includes is empty but excludes is not, all not excluded exceptions are retried
  * @return exception types not to retry
  */
 Class<? extends Throwable>[] exclude() default {};

 /**
  * A unique label for statistics reporting. If not provided the caller may choose to
  * ignore it, or provide a default.
  *
  * @return the label for the statistics
  */
 String label() default "";

 /**
  * Flag to say that the retry is stateful: i.e. exceptions are re-thrown, but the
  * retry policy is applied with the same policy to subsequent invocations with the
  * same arguments. If false then retryable exceptions are not re-thrown.
  * @return true if retry is stateful, default false
  */
 boolean stateful() default false;

 /**
  * @return the maximum number of attempts (including the first failure), defaults to 3
  */
 int maxAttempts() default 3;

 /**
  * @return an expression evaluated to the maximum number of attempts (including the first failure), defaults to 3
  * Overrides {@link #maxAttempts()}.
  * @date 1.2
  */
 String maxAttemptsExpression() default "";

 /**
  * Specify the backoff properties for retrying this operation. The default is a
  * simple {@link Backoff} specification with no properties - see it's documentation
  * for defaults.
  * @return a backoff specification
  */
 Backoff backoff() default @Backoff();

 /**
  * Specify an expression to be evaluated after the {@code SimpleRetryPolicy.canRetry()}
  * returns true - can be used to conditionally suppress the retry. Only invoked after
  * an exception is thrown. The root object for the evaluation is the last {@code Throwable}.
  * Other beans in the context can be referenced.
  * For example:
  * <pre class=code>
  *  {@code "message.contains('you can retry this')"}.
  * </pre>
  * and
  * <pre class=code>
  *  {@code "@someBean.shouldRetry(#root)"}.
  * </pre>
  * @return the expression.
  * @date 1.2
  */
 String exceptionExpression() default "";

 /**
  * Bean names of retry listeners to use instead of default ones defined in Spring context
  * @return retry listeners bean names
  */
 String[] listeners() default {};

}

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Backoff {

 /**
  * Synonym for {@link #delay()}.
  *
  * @return the delay in milliseconds (default 1000)
  */
 long value() default 1000;

 /**
  * A canonical backoff period. Used as an initial value in the exponential case, and
  * as a minimum value in the uniform case.
  * @return the initial or canonical backoff period in milliseconds (default 1000)
  */
 long delay() default 0;

 /**
  * The maximimum wait (in milliseconds) between retries. If less than the
  * {@link #delay()} then the default of
  * {@value org.springframework.retry.backoff.ExponentialBackOffPolicy#DEFAULT_MAX_INTERVAL}
  * is applied.
  *
  * @return the maximum delay between retries (default 0 = ignored)
  */
 long maxDelay() default 0;

 /**
  * If positive, then used as a multiplier for generating the next delay for backoff.
  *
  * @return a multiplier to use to calculate the next backoff delay (default 0 =
  * ignored)
  */
 double multiplier() default 0;

 /**
  * An expression evaluating to the canonical backoff period. Used as an initial value
  * in the exponential case, and as a minimum value in the uniform case. Overrides
  * {@link #delay()}.
  * @return the initial or canonical backoff period in milliseconds.
  * @date 1.2
  */
 String delayExpression() default "";

 /**
  * An expression evaluating to the maximimum wait (in milliseconds) between retries.
  * If less than the {@link #delay()} then the default of
  * {@value org.springframework.retry.backoff.ExponentialBackOffPolicy#DEFAULT_MAX_INTERVAL}
  * is applied. Overrides {@link #maxDelay()}
  *
  * @return the maximum delay between retries (default 0 = ignored)
  * @date 1.2
  */
 String maxDelayExpression() default "";

 /**
  * Evaluates to a vaule used as a multiplier for generating the next delay for
  * backoff. Overrides {@link #multiplier()}.
  *
  * @return a multiplier expression to use to calculate the next backoff delay (default
  * 0 = ignored)
  * @date 1.2
  */
 String multiplierExpression() default "";

 /**
  * In the exponential case ({@link #multiplier()} > 0) set this to true to have the
  * backoff delays randomized, so that the maximum delay is multiplier times the
  * previous delay and the distribution is uniform between the two values.
  *
  * @return the flag to signal randomization is required (default false)
  */
 boolean random() default false;
}

@Component
public class PlatformClassService {
    @Retryable(
        // 重試異常的異常類型
        value = {Exception.class},
        // 最大重試次數
        maxAttempts = 5,
        // 設置回退延遲時間
        backoff = @Backoff(delay = 500),
        // 配置回調方法名稱
        listeners = "retryListener"
    )
    public void call() {
        System.out.println("call...");
        throw new RuntimeException("手工異常");
    }
}

// 初始延遲2秒，然後之後驗收1.5倍延遲重試，總重試次數4
@Retryable(value = {Exception.class}, maxAttempts = 4, backoff = @Backoff(delay = 2000L, multiplier = 1.5))

/**
  * 註解調用
  */
@Bean
public RetryListener retryListener() {
    return new RetryListener() {
        @Override
        public <T, E extends Throwable> boolean open(RetryContext context, RetryCallback<T, E> callback) {
            System.out.println("open context = " + context + ", callback = " + callback);
            // 返回true繼續執行後續調用
            return true;
        }

        @Override
        public <T, E extends Throwable> void close(RetryContext context, RetryCallback<T, E> callback,
                                                   Throwable throwable) {
            System.out.println("close context = " + context + ", callback = " + callback);
        }
        @Override
        public <T, E extends Throwable> void onError(RetryContext context, RetryCallback<T, E> callback,
                                                     Throwable throwable) {
            System.out.println("onError context = " + context + ", callback = " + callback);
        }
    };
}

@RestController
public class SpringRetryController {
    @Resource
    private PlatformClassService platformClassService;
    
    @RequestMapping("/retryPlatformCall")
    public Object retryPlatformCall() {
        try {
            platformClassService.call();
        } catch (Exception e) {
            return "嘗試調用失敗";
        }
        return "retryPlatformCall";
    }
}