/**
* Copyright (C) 2012 Ryan W Tenney (ryan@10e.us)
*
* 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.ryantenney.metrics.spring.config.annotation;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import com.codahale.metrics.MetricRegistry;
import com.codahale.metrics.health.HealthCheckRegistry;
/**
* A {@link MetricsConfigurer} implementation that delegates to other {@link MetricsConfigurer} instances.
*
* @author Ryan Tenney
* @since 3.0
*/
public class MetricsConfigurerComposite implements MetricsConfigurer {
private final List<MetricsConfigurer> configurers = new ArrayList<MetricsConfigurer>();
public void addMetricsConfigurers(final Collection<MetricsConfigurer> configurers) {
if (configurers != null) {
this.configurers.addAll(configurers);
}
}
@Override
public void configureReporters(final MetricRegistry metricRegistry) {
for (MetricsConfigurer configurer : this.configurers) {
configurer.configureReporters(metricRegistry);
}
}
@Override
public MetricRegistry getMetricRegistry() {
final List<MetricRegistry> candidates = new ArrayList<MetricRegistry>();
for (MetricsConfigurer configurer : this.configurers) {
final MetricRegistry metricRegistry = configurer.getMetricRegistry();
if (metricRegistry != null) {
candidates.add(metricRegistry);
}
}
MetricRegistry instance = selectSingleInstance(candidates, MetricRegistry.class);
if (instance == null) {
instance = new MetricRegistry();
}
return instance;
}
@Override
public HealthCheckRegistry getHealthCheckRegistry() {
final List<HealthCheckRegistry> candidates = new ArrayList<HealthCheckRegistry>();
for (MetricsConfigurer configurer : this.configurers) {
final HealthCheckRegistry healthCheckRegistry = configurer.getHealthCheckRegistry();
if (healthCheckRegistry != null) {
candidates.add(healthCheckRegistry);
}
}
HealthCheckRegistry instance = selectSingleInstance(candidates, HealthCheckRegistry.class);
if (instance == null) {
instance = new HealthCheckRegistry();
}
return instance;
}
private <T> T selectSingleInstance(final List<T> instances, final Class<T> instanceType) {
if (instances.size() > 1) {
throw new IllegalStateException("Only one [" + instanceType + "] was expected but multiple instances were provided: " + instances);
}
else if (instances.size() == 1) {
return instances.get(0);
}
else {
return null;
}
}
}