org.opencastproject.util.RequireUtil Maven / Gradle / Ivy
/*
* Licensed to The Apereo Foundation under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
*
* The Apereo Foundation licenses this file to you under the Educational
* Community 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://opensource.org/licenses/ecl2.txt
*
* 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.opencastproject.util;
import org.apache.commons.lang3.StringUtils;
/**
* Utility functions for handling common requirements.
*/
public final class RequireUtil {
private RequireUtil() {
}
/**
* Require an expression to hold true.
*
* @param expr
* the expression
* @param exprName
* the name of the expression used to create an error message in case expr evaluates to false
* @throws IllegalArgumentException
* in case expr evaluates to false
*/
public static void requireTrue(boolean expr, String exprName) {
if (!expr) {
throw new IllegalArgumentException("Requirement '" + exprName + "' must hold true");
}
}
/**
* The given value must not be null.
*
* Example:
*
*
* class A {
* private String a;
*
* A(String a) {
* this.a = notNull(a, "a");
* }
* }
*
*
* @param value
* the value to check for null
* @param valueName
* the name of the value; used in error message
* @return the value, if it is not null
* @throws IllegalArgumentException
* in case of value being null
*/
public static A notNull(A value, String valueName) {
if (value == null)
throw new IllegalArgumentException(valueName + " must not be null");
return value;
}
/**
* The given value must not be null or empty.
*
* Example:
*
*
* class A {
* private String a;
*
* A(String a) {
* this.a = notEmpty(a, "a");
* }
* }
*
*
* @param value
* the value to check for emptiness
* @param valueName
* the name of the value; used in error message
* @return the value, if it is not empty
* @throws IllegalArgumentException
* in case of value being empty
*/
public static String notEmpty(String value, String valueName) {
if (StringUtils.isEmpty(value))
throw new IllegalArgumentException(valueName + " must not be null or empty");
return value;
}
/**
* The given string value must not be blank, empty nor {@code null}. Otherwise, an {@link IllegalArgumentException} is
* thrown.
*
* @param value
* the value to check for not being empty
* @param valueName
* the name of the value
* @return the value, if not blank
*/
public static String requireNotBlank(String value, String valueName) {
if (StringUtils.isBlank(value))
throw new IllegalArgumentException(valueName + " must not be null or blank");
return value;
}
public static double between(double value, double min, double max) {
if (min <= value && value <= max)
return value;
throw new IllegalArgumentException(value + " must be between " + min + " and " + max);
}
public static int min(int value, int min) {
if (min <= value)
return value;
throw new IllegalArgumentException(value + " must not be smaller than " + min);
}
}