private RetryContext doOpenInternal(RetryPolicy retryPolicy, RetryState state) {
RetryContext context = retryPolicy.open(RetrySynchronizationManager.getContext());
if (state != null) {
context.setAttribute(RetryContext.STATE_KEY, state.getKey());
}
if (context.hasAttribute(GLOBAL_STATE)) {
registerContext(context, state);
}
return context;
}
/**
* Execute the callback once if the policy dictates that we can, otherwise execute the recovery
* callback.
*
* @param recoveryCallback the {@link RecoveryCallback}
* @param retryCallback the {@link RetryCallback}
* @param state the {@link RetryState}
* @param <T> the type of the return value
* @param <E> the exception type to throw
* @see RetryOperations#execute(RetryCallback, RecoveryCallback, RetryState)
* @throws ExhaustedRetryException if the retry has been exhausted.
* @throws E an exception if the retry operation fails
* @return T the retried value
*/
protected <T, E extends Throwable> T doExecute(
RetryCallback<T, E> retryCallback, RecoveryCallback<T> recoveryCallback, RetryState state)
throws E, ExhaustedRetryException {
RetryPolicy retryPolicy = this.retryPolicy;
BackOffPolicy backOffPolicy = this.backOffPolicy;
// Allow the retry policy to initialise itself...
RetryContext context = open(retryPolicy, state);
if (this.logger.isTraceEnabled()) {
this.logger.trace("RetryContext retrieved: " + context);
}
// Make sure the context is available globally for clients who need
// it...
RetrySynchronizationManager.register(context);
Throwable lastException = null;
boolean exhausted = false;
try {
// Give clients a chance to enhance the context...
boolean running = doOpenInterceptors(retryCallback, context);
if (!running) {
throw new TerminatedRetryException(
"Retry terminated abnormally by interceptor before first attempt");
}
// Get or Start the backoff context...
BackOffContext backOffContext = null;
Object resource = context.getAttribute("backOffContext");
if (resource instanceof BackOffContext) {
backOffContext = (BackOffContext) resource;
}
if (backOffContext == null) {
backOffContext = backOffPolicy.start(context);
if (backOffContext != null) {
context.setAttribute("backOffContext", backOffContext);
}
}
/*
* We allow the whole loop to be skipped if the policy or context already
* forbid the first try. This is used in the case of external retry to allow a
* recovery in handleRetryExhausted without the callback processing (which
* would throw an exception).
*/
while (canRetry(retryPolicy, context) && !context.isExhaustedOnly()) {
try {
if (this.logger.isDebugEnabled()) {
this.logger.debug("Retry: count=" + context.getRetryCount());
}
// Reset the last exception, so if we are successful
// the close interceptors will not think we failed...
lastException = null;
return retryCallback.doWithRetry(context);
} catch (Throwable e) {
lastException = e;
try {
registerThrowable(retryPolicy, state, context, e);
} catch (Exception ex) {
throw new TerminatedRetryException("Could not register throwable", ex);
} finally {
doOnErrorInterceptors(retryCallback, context, e);
}
if (canRetry(retryPolicy, context) && !context.isExhaustedOnly()) {
try {
backOffPolicy.backOff(backOffContext);
} catch (BackOffInterruptedException ex) {
lastException = e;
// back off was prevented by another thread - fail the retry
if (this.logger.isDebugEnabled()) {
this.logger.debug(
"Abort retry because interrupted: count=" + context.getRetryCount());
}
throw ex;
}
}
if (this.logger.isDebugEnabled()) {
this.logger.debug("Checking for rethrow: count=" + context.getRetryCount());
}
if (shouldRethrow(retryPolicy, context, state)) {
if (this.logger.isDebugEnabled()) {
this.logger.debug("Rethrow in retry for policy: count=" + context.getRetryCount());
}
throw RetryTemplate.<E>wrapIfNecessary(e);
}
}
/*
* A stateful attempt that can retry may rethrow the exception before now,
* but if we get this far in a stateful retry there's a reason for it,
* like a circuit breaker or a rollback classifier.
*/
if (state != null && context.hasAttribute(GLOBAL_STATE)) {
break;
}
}
if (state == null && this.logger.isDebugEnabled()) {
this.logger.debug("Retry failed last attempt: count=" + context.getRetryCount());
}
exhausted = true;
return handleRetryExhausted(recoveryCallback, context, state);
} catch (Throwable e) {
throw RetryTemplate.<E>wrapIfNecessary(e);
} finally {
close(retryPolicy, context, state, lastException == null || exhausted);
doCloseInterceptors(retryCallback, context, lastException);
RetrySynchronizationManager.clear();
}
}
