com.watchrabbit.executor.service.CircuitBreakerServiceImpl Maven / Gradle / Ivy
/*
* Copyright 2014 Mariusz.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.watchrabbit.executor.service;
import com.watchrabbit.executor.exception.CircuitOpenException;
import com.watchrabbit.executor.wrapper.CircuitBreaker;
import com.watchrabbit.executor.wrapper.CommandConfig;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* @author Mariusz
*/
public class CircuitBreakerServiceImpl implements CircuitBreakerService {
private static final Logger LOGGER = LoggerFactory.getLogger(CircuitBreakerServiceImpl.class);
private static final ConcurrentHashMap circuitBreakers = new ConcurrentHashMap<>();
@Override
public Callable addCircuitBreaker(Callable callable, CommandConfig commandConfig) {
if (!circuitBreakers.containsKey(commandConfig.getCommandName())) {
createCircuitBreaker(commandConfig);
}
CircuitBreaker breaker = circuitBreakers.get(commandConfig.getCommandName());
return wrap(callable, breaker, commandConfig);
}
private static synchronized void createCircuitBreaker(CommandConfig commandConfig) {
if (!circuitBreakers.containsKey(commandConfig.getCommandName())) {
CircuitBreaker circuitBreaker = new CircuitBreaker(commandConfig.getBreakerRetryTimeout());
circuitBreaker.setCommandName(commandConfig.getCommandName());
circuitBreakers.put(commandConfig.getCommandName(), circuitBreaker);
}
}
private Callable wrap(Callable callable, CircuitBreaker breaker, CommandConfig commandConfig) {
List> excludedExceptions = commandConfig.getExcludedExceptions();
if (excludedExceptions == null) {
excludedExceptions = Collections.emptyList();
}
return wrap(callable, breaker, excludedExceptions);
}
private Callable wrap(Callable callable, CircuitBreaker breaker, List> excludedExceptions) {
return () -> {
if (!breaker.isClosed()) {
LOGGER.debug("Circut is open, skipping command {} execution and throwing exception", breaker.getCommandName());
throw new CircuitOpenException();
} else {
LOGGER.debug("Circut is closed, executing command: {}", breaker.getCommandName());
try {
return callable.call();
} catch (Exception ex) {
if (!excludedExceptions.contains(ex.getClass())) {
breaker.open();
}
throw ex;
}
}
};
}
}