Java tutorial
/* * Copyleft 2016 by Red Hat. * * 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. */ /* * : Everything is a potential metric . */ package org.jam.metrics.applicationmetrics.utils; import static com.google.common.base.Preconditions.checkArgument; import java.util.Collections; import java.util.Map; import java.util.Objects; import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.base.MoreObjects; import io.swagger.annotations.ApiModelProperty; /** * A metric data point consists of a timestamp and a value. The data type of the value will vary depending on the metric * type. The data point may also include tags which are stored as a map of key/value pairs. * * @author jsanda */ public class DataPoint<T> { protected final long timestamp; protected final T value; protected final Map<String, String> tags; @JsonCreator(mode = JsonCreator.Mode.PROPERTIES) public DataPoint(@JsonProperty("timestamp") Long timestamp, @JsonProperty("value") T value) { checkArgument(timestamp != null, "Data point timestamp is null"); checkArgument(value != null, "Data point value is null"); this.timestamp = timestamp; this.value = value; tags = Collections.emptyMap(); } public DataPoint(Long timestamp, T value, Map<String, String> tags) { checkArgument(timestamp != null, "Data point timestamp is null"); checkArgument(value != null, "Data point value is null"); this.timestamp = timestamp; this.value = value; this.tags = Collections.unmodifiableMap(tags); } @ApiModelProperty(required = true) public long getTimestamp() { return timestamp; } @ApiModelProperty(required = true) public T getValue() { return value; } @ApiModelProperty(required = false) public Map<String, String> getTags() { return tags; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; DataPoint<?> dataPoint = (DataPoint<?>) o; return Objects.equals(timestamp, dataPoint.timestamp) && Objects.equals(value, dataPoint.value) && Objects.equals(tags, dataPoint.tags); } @Override public int hashCode() { return Objects.hash(timestamp, value, tags); } @Override public String toString() { return MoreObjects.toStringHelper(this).add("timestamp", timestamp).add("value", value).add("tags", tags) .omitNullValues().toString(); } }