/*
* Copyright 2013-2015 the original author or authors.
*
* 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 org.springframework.cloud.netflix.metrics;
import java.util.Collection;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.netflix.metrics.servo.ServoMonitorCache;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import com.netflix.servo.MonitorRegistry;
import com.netflix.servo.monitor.MonitorConfig;
import com.netflix.servo.tag.SmallTagMap;
import com.netflix.servo.tag.Tags;
import static org.springframework.web.context.request.RequestAttributes.SCOPE_REQUEST;
/**
* Intercepts incoming HTTP requests and records metrics about execution time and results.
*
* @author Jon Schneider
*/
public class MetricsHandlerInterceptor extends HandlerInterceptorAdapter {
@Value("${netflix.metrics.rest.metricName:rest}")
String metricName;
@Value("${netflix.metrics.rest.callerHeader:#{null}}")
String callerHeader;
@Autowired
MonitorRegistry registry;
@Autowired
ServoMonitorCache servoMonitorCache;
@Autowired
Collection<MetricsTagProvider> tagProviders;
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
Object handler) throws Exception {
RequestContextHolder.getRequestAttributes().setAttribute("requestStartTime",
System.nanoTime(), SCOPE_REQUEST);
return super.preHandle(request, response, handler);
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
Object handler, Exception ex) throws Exception {
RequestContextHolder.getRequestAttributes().setAttribute("exception", ex,
SCOPE_REQUEST);
Long startTime = (Long) RequestContextHolder.getRequestAttributes().getAttribute(
"requestStartTime", SCOPE_REQUEST);
if (startTime != null)
recordMetric(request, response, handler, startTime);
super.afterCompletion(request, response, handler, ex);
}
protected void recordMetric(HttpServletRequest request, HttpServletResponse response,
Object handler, Long startTime) {
String caller = null;
if (callerHeader != null) {
caller = request.getHeader(callerHeader);
}
SmallTagMap.Builder builder = SmallTagMap.builder();
for (MetricsTagProvider tagProvider : tagProviders) {
Map<String, String> tags = tagProvider.httpRequestTags(request, response,
handler, caller);
for (Map.Entry<String, String> tag : tags.entrySet()) {
builder.add(Tags.newTag(tag.getKey(), tag.getValue()));
}
}
MonitorConfig.Builder monitorConfigBuilder = MonitorConfig.builder(metricName);
monitorConfigBuilder.withTags(builder);
servoMonitorCache.getTimer(monitorConfigBuilder.build()).record(
System.nanoTime() - startTime, TimeUnit.NANOSECONDS);
}
}