com.github.triceo.robozonky.strategy.InvestmentStrategyLoader Maven / Gradle / Ivy
/*
* Copyright 2016 Lukáš Petrovický
*
* 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.github.triceo.robozonky.strategy;
import java.io.File;
import java.util.Optional;
import java.util.ServiceLoader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Implements Java's {@link ServiceLoader} to provide suitable {@link InvestmentStrategy} implementations.
*/
class InvestmentStrategyLoader {
private static final Logger LOGGER = LoggerFactory.getLogger(InvestmentStrategyLoader.class);
private static final ServiceLoader STRATEGY_LOADER =
ServiceLoader.load(InvestmentStrategyService.class);
static Optional load(final File file) throws InvestmentStrategyParseException {
if (file == null) {
throw new NullPointerException("Strategy file can not be null.");
} else if (!file.canRead()) {
throw new InvestmentStrategyParseException("Strategy file not accessible: " + file.getAbsolutePath());
}
InvestmentStrategyLoader.LOGGER.trace("Loading strategies.");
try {
for (final InvestmentStrategyService s : InvestmentStrategyLoader.STRATEGY_LOADER) {
if (s.isSupported(file)) {
InvestmentStrategyLoader.LOGGER.debug("Strategy '{}' will be processed using '{}'.", file.getAbsolutePath(),
s.getClass());
return Optional.of(s.parse(file));
} else {
InvestmentStrategyLoader.LOGGER.trace("Strategy '{}' will not be processed using '{}'.",
file.getAbsolutePath(), s.getClass());
}
}
InvestmentStrategyLoader.LOGGER.warn("No strategy implementation found for '{}'.", file.getAbsolutePath());
return Optional.empty();
} finally {
InvestmentStrategyLoader.LOGGER.trace("Finished loading strategies.");
}
}
}