/**
* 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;
import java.lang.reflect.Method;
import org.springframework.core.Ordered;
import org.springframework.util.ReflectionUtils;
import com.codahale.metrics.MetricRegistry;
import com.ryantenney.metrics.annotation.CachedGauge;
import static com.ryantenney.metrics.spring.AnnotationFilter.INSTANCE_METHODS;
class CachedGaugeAnnotationBeanPostProcessor extends AbstractAnnotationBeanPostProcessor implements Ordered {
private static final AnnotationFilter FILTER = new AnnotationFilter(CachedGauge.class, INSTANCE_METHODS);
private final MetricRegistry metrics;
public CachedGaugeAnnotationBeanPostProcessor(final MetricRegistry metrics) {
super(Members.METHODS, Phase.POST_INIT, FILTER);
this.metrics = metrics;
}
@Override
protected void withMethod(final Object bean, String beanName, Class<?> targetClass, final Method method) {
if (method.getParameterTypes().length > 0) {
throw new IllegalStateException("Method " + method.getName() + " is annotated with @CachedGauge but requires parameters.");
}
final CachedGauge annotation = method.getAnnotation(CachedGauge.class);
final String metricName = Util.forCachedGauge(targetClass, method, annotation);
metrics.register(metricName, new com.codahale.metrics.CachedGauge<Object>(annotation.timeout(), annotation.timeoutUnit()) {
@Override
protected Object loadValue() {
return ReflectionUtils.invokeMethod(method, bean);
}
});
LOG.debug("Created cached gauge {} for method {}.{}", metricName, targetClass.getCanonicalName(), method.getName());
}
@Override
public int getOrder() {
return LOWEST_PRECEDENCE;
}
}