Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 gobblin.metrics; import java.util.Collection; import java.util.Collections; import java.util.List; import java.util.Map; import com.google.common.base.Preconditions; import com.google.common.base.Joiner; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import com.google.common.collect.Maps; /** * A base implementation of {@link Taggable}. * * @author Yinan Li */ public class Tagged implements Taggable { protected final Map<String, Object> tags; public Tagged() { this.tags = Maps.newLinkedHashMap(); } public Tagged(Collection<Tag<?>> tags) { this.tags = Maps.newLinkedHashMap(); addTags(tags); } @Override public void addTag(Tag<?> tag) { Preconditions.checkNotNull(tag, "Cannot add a null Tag"); Preconditions.checkNotNull(tag.getValue(), "Cannot add a Tag with a null value. Tag: " + tag); this.tags.put(tag.getKey(), tag.getValue()); } @Override public void addTags(Collection<Tag<?>> tags) { for (Tag<?> tag : tags) { addTag(tag); } } @Override public List<Tag<?>> getTags() { ImmutableList.Builder<Tag<?>> builder = ImmutableList.builder(); for (Map.Entry<String, Object> entry : this.tags.entrySet()) { builder.add(new Tag<Object>(entry.getKey(), entry.getValue())); } return builder.build(); } /** * Return tags as a Map. * @return map of tags. */ public Map<String, Object> getTagMap() { return ImmutableMap.copyOf(this.tags); } /** * Get a metric name constructed from the {@link Tag}s. */ @Override public String metricNamePrefix(boolean includeTagKeys) { return Joiner.on('.').join(includeTagKeys ? getTags() : this.tags.values()); } }