com.netflix.spectator.impl.Preconditions Maven / Gradle / Ivy
/**
* Copyright 2015 Netflix, Inc.
*
* 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 com.netflix.spectator.impl;
/**
* Internal convenience methods that help a method or constructor check whether it was invoked
* correctly. Please notice that this should be considered an internal implementation detail, and
* it is subject to change without notice.
*/
public final class Preconditions {
private Preconditions() {
}
/**
* Ensures the object reference is not null.
*/
public static T checkNotNull(T obj, String name) {
if (obj == null) {
String msg = String.format("parameter '%s' cannot be null", name);
throw new NullPointerException(msg);
}
return obj;
}
/**
* Ensures the truth of an expression involving the state of the calling instance.
*/
public static void checkArg(boolean expression, String errMsg) {
if (!expression) {
throw new IllegalArgumentException(errMsg);
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance.
*/
public static void checkState(boolean expression, String errMsg) {
if (!expression) {
throw new IllegalStateException(errMsg);
}
}
}