Java tutorial
/* * Copyright 2014 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 ratpack.dropwizard.metrics.internal; import com.codahale.metrics.*; import com.codahale.metrics.json.MetricsModule; import com.fasterxml.jackson.databind.ObjectMapper; import io.netty.buffer.ByteBuf; import io.netty.buffer.ByteBufAllocator; import io.netty.buffer.ByteBufOutputStream; import ratpack.func.Function; import java.io.OutputStream; import java.util.concurrent.TimeUnit; public class MetricRegistryJsonMapper implements Function<MetricRegistry, ByteBuf> { private final ObjectMapper mapper; private final ByteBufAllocator byteBufAllocator; public MetricRegistryJsonMapper(ByteBufAllocator byteBufAllocator, MetricFilter filter) { this.byteBufAllocator = byteBufAllocator; this.mapper = new ObjectMapper() .registerModule(new MetricsModule(TimeUnit.SECONDS, TimeUnit.MILLISECONDS, false, filter)); } @Override public ByteBuf apply(MetricRegistry metricRegistry) throws Exception { ByteBuf byteBuf = byteBufAllocator.ioBuffer(); try { OutputStream out = new ByteBufOutputStream(byteBuf); mapper.writeValue(out, metricRegistry); return byteBuf; } catch (Exception e) { byteBuf.release(); throw e; } } }