org.osgi.util.measurement.State Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2002, 2013). All Rights Reserved.
*
* 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.osgi.util.measurement;
/**
* Groups a state name, value and timestamp.
*
*
* The state itself is represented as an integer and the time is measured in
* milliseconds since midnight, January 1, 1970 UTC.
*
*
* A {@code State} object is immutable so that it may be easily shared.
*
* @Immutable
* @author $Id: 415613f3925b2d69f27517c1ef2fc389507b62dc $
*/
public class State {
private final int value;
private final long time;
private final String name;
/**
* Create a new {@code State} object.
*
* @param value The value of the state.
* @param name The name of the state.
* @param time The time measured in milliseconds since midnight, January 1,
* 1970 UTC.
*/
public State(int value, String name, long time) {
this.value = value;
this.name = name;
this.time = time;
}
/**
* Create a new {@code State} object with a time of 0.
*
* @param value The value of the state.
* @param name The name of the state.
*/
public State(int value, String name) {
this(value, name, 0);
}
/**
* Returns the value of this {@code State}.
*
* @return The value of this {@code State} object.
*/
public final int getValue() {
return value;
}
/**
* Returns the time with which this {@code State} was created.
*
* @return The time with which this {@code State} was created. The time is
* measured in milliseconds since midnight, January 1, 1970 UTC.
*/
public final long getTime() {
return time;
}
/**
* Returns the name of this {@code State}.
*
* @return The name of this {@code State} object.
*/
public final String getName() {
return name;
}
/**
* Returns a {@code String} object representing this object.
*
* @return a {@code String} object representing this object.
*/
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append(value);
if (name != null) {
sb.append(" \"");
sb.append(name);
sb.append("\"");
}
return sb.toString();
}
/**
* Returns a hash code value for this object.
*
* @return A hash code value for this object.
*/
public int hashCode() {
int hash = 31 * 17 + value;
if (name != null) {
hash = 31 * hash + name.hashCode();
}
return hash;
}
/**
* Return whether the specified object is equal to this object. Two
* {@code State} objects are equal if they have same value and name.
*
* @param obj The object to compare with this object.
* @return {@code true} if this object is equal to the specified object;
* {@code false} otherwise.
*/
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof State)) {
return false;
}
State that = (State) obj;
if (value != that.value) {
return false;
}
if (name == that.name) {
return true;
}
if (name == null) {
return false;
}
return name.equals(that.name);
}
}