com.netflix.servo.util.Preconditions Maven / Gradle / Ivy
/**
* Copyright 2014 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.servo.util;
/**
* 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 one or more parameters to the
* calling method.
*
* @param expression a boolean expression
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(boolean expression, String errorMessage) {
checkArgument(expression, errorMessage, null);
}
/**
* Ensures the truth of an expression involving one or more parameters to the
* calling method.
*
*
* @param expression a boolean expression
* @param errorMessage the error message that can be a formattable string
* @param args arguments if using a formatted string
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(boolean expression, String errorMessage, String... args) {
if (!expression) {
if (args != null && args.length > 0) {
String message = String.format(errorMessage, args);
throw new IllegalArgumentException(message);
} else {
throw new IllegalArgumentException(errorMessage);
}
}
}
}