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/*
* Copyright 2002-2013 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 spark.utils;
/**
* Assertion utility class that assists in validating arguments.
* Useful for identifying programmer errors early and clearly at runtime.
* For example, if the contract of a public method states it does not
* allow {@code null} arguments, Assert can be used to validate that
* contract. Doing this clearly indicates a contract violation when it
* occurs and protects the class's invariants.
*
Typically used to validate method arguments rather than configuration
* properties, to check for cases that are usually programmer errors rather than
* configuration errors. In contrast to config initialization code, there is
* usally no point in falling back to defaults in such methods.
*
This class is similar to JUnit's assertion library. If an argument value is
* deemed invalid, an {@link IllegalArgumentException} is thrown (typically).
*
* @author Keith Donald
* @author Juergen Hoeller
* @author Colin Sampaleanu
* @author Rob Harrop
*
* Code copied from Spring source. Modifications made (mostly removal of methods) by Per Wendel.
*/
public abstract class Assert {
/**
* Assert a boolean expression, throwing {@code IllegalArgumentException}
* if the test result is {@code false}.
*
Assert.isTrue(i > 0, "The value must be greater than zero");
*
* @param expression a boolean expression
* @param message the exception message to use if the assertion fails
* @throws IllegalArgumentException if expression is {@code false}
*/
public static void isTrue(boolean expression, String message) {
if (!expression) {
throw new IllegalArgumentException(message);
}
}
/**
* Assert that an object is not {@code null} .
* Assert.notNull(clazz, "The class must not be null");
*
* @param object the object to check
* @param message the exception message to use if the assertion fails
* @throws IllegalArgumentException if the object is {@code null}
*/
public static void notNull(Object object, String message) {
if (object == null) {
throw new IllegalArgumentException(message);
}
}
/**
* Assert that an object is not {@code null} .
* Assert.notNull(clazz);
*
* @param object the object to check
* @throws IllegalArgumentException if the object is {@code null}
*/
public static void notNull(Object object) {
notNull(object, "[Assertion failed] - this argument is required; it must not be null");
}
/**
* Assert that the given String is not empty; that is,
* it must not be {@code null} and not the empty String.
* Assert.hasLength(name, "Name must not be empty");
*
* @param text the String to check
* @param message the exception message to use if the assertion fails
* @see StringUtils#hasLength
*/
public static void hasLength(String text, String message) {
if (!StringUtils.hasLength(text)) {
throw new IllegalArgumentException(message);
}
}
/**
* Assert that an array has elements; that is, it must not be
* {@code null} and must have at least one element.
* Assert.notEmpty(array, "The array must have elements");
*
* @param array the array to check
* @param message the exception message to use if the assertion fails
* @throws IllegalArgumentException if the object array is {@code null} or has no elements
*/
public static void notEmpty(Object[] array, String message) {
if (ObjectUtils.isEmpty(array)) {
throw new IllegalArgumentException(message);
}
}
/**
* Assert a boolean expression, throwing {@code IllegalStateException}
* if the test result is {@code false}. Call isTrue if you wish to
* throw IllegalArgumentException on an assertion failure.
* Assert.state(id == null, "The id property must not already be initialized");
*
* @param expression a boolean expression
* @param message the exception message to use if the assertion fails
* @throws IllegalStateException if expression is {@code false}
*/
public static void state(boolean expression, String message) {
if (!expression) {
throw new IllegalStateException(message);
}
}
}