/*
* Copyright 2012-2017 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.boot.actuate.metrics;
import java.util.Date;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
/**
* Immutable class that can be used to hold any arbitrary system measurement value (a
* named numeric value with a timestamp). For example a metric might record the number of
* active connections to a server, or the temperature of a meeting room.
*
* @param <T> the value type
* @author Dave Syer
*/
public class Metric<T extends Number> {
private final String name;
private final T value;
private final Date timestamp;
/**
* Create a new {@link Metric} instance for the current time.
* @param name the name of the metric
* @param value the value of the metric
*/
public Metric(String name, T value) {
this(name, value, new Date());
}
/**
* Create a new {@link Metric} instance.
* @param name the name of the metric
* @param value the value of the metric
* @param timestamp the timestamp for the metric
*/
public Metric(String name, T value, Date timestamp) {
Assert.notNull(name, "Name must not be null");
this.name = name;
this.value = value;
this.timestamp = timestamp;
}
/**
* Returns the name of the metric.
* @return the name
*/
public String getName() {
return this.name;
}
/**
* Returns the value of the metric.
* @return the value
*/
public T getValue() {
return this.value;
}
public Date getTimestamp() {
return this.timestamp;
}
@Override
public String toString() {
return "Metric [name=" + this.name + ", value=" + this.value + ", timestamp="
+ this.timestamp + "]";
}
/**
* Create a new {@link Metric} with an incremented value.
* @param amount the amount that the new metric will differ from this one
* @return a new {@link Metric} instance
*/
public Metric<Long> increment(int amount) {
return new Metric<>(this.getName(),
Long.valueOf(this.getValue().longValue() + amount));
}
/**
* Create a new {@link Metric} with a different value.
* @param <S> the metric value type
* @param value the value of the new metric
* @return a new {@link Metric} instance
*/
public <S extends Number> Metric<S> set(S value) {
return new Metric<>(this.getName(), value);
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ObjectUtils.nullSafeHashCode(this.name);
result = prime * result + ObjectUtils.nullSafeHashCode(this.timestamp);
result = prime * result + ObjectUtils.nullSafeHashCode(this.value);
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (obj instanceof Metric) {
Metric<?> other = (Metric<?>) obj;
boolean rtn = true;
rtn = rtn && ObjectUtils.nullSafeEquals(this.name, other.name);
rtn = rtn && ObjectUtils.nullSafeEquals(this.timestamp, other.timestamp);
rtn = rtn && ObjectUtils.nullSafeEquals(this.value, other.value);
return rtn;
}
return super.equals(obj);
}
}