org.openide.util.Parameters Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.openide.util;
/**
* Utilities for checking the values of method parameters.
*
* Methods in this class generally take the name of
* the parameter to check and its value and throw exceptions
* with messages according to the method name or just return. For example,
* if you have a myMethod() method taking a myParam
* parameter whose value must be a Java identifier, you usually check that
* by doing:
*
*
* public void myMethod(String myParam) {
* if (!Utilities.isJavaIdentifier(myParam)) {
* throw new IllegalArgumentException("The myParam parameter is not a valid Java identifier");
* }
* }
*
*
* Using this class you can do the same in a simpler way:
*
*
* public void myMethod(String myParam) {
* Parameters.javaIdentifier("myParam", myParam);
* }
*
*
* @author Andrei Badea
* @since org.openide.util 7.6
*/
public class Parameters {
private Parameters() {}
/**
* Asserts the parameter value is not null.
* Use {@code java.util.Objects.requireNonNull} in JDK 7.
* @param name the parameter name.
* @param value the parameter value.
* @throws NullPointerException if the parameter value is null.
*/
public static void notNull(CharSequence name, Object value) {
if (value == null) {
throw new NullPointerException("The " + name + " parameter cannot be null"); // NOI18N
}
}
/**
* Asserts the parameter value is neither null nor an empty
* character sequence.
*
* @param name the parameter name.
* @param value the parameter value.
* @throws NullPointerException if the parameter value is null.
* @throws IllegalArgumentException if the parameter value is an empty
* character sequence.
*/
public static void notEmpty(CharSequence name, CharSequence value) {
notNull(name, value);
if (value.length() == 0) {
throw new IllegalArgumentException("The " + name + " parameter cannot be an empty character sequence"); // NOI18N
}
}
/**
* Asserts the parameter value is not null and it contains
* at least one non-whitespace character. Whitespace is defined as by
* {@link String#trim}.
*
* @param name the parameter name.
* @param value the parameter value.
* @throws NullPointerException if the parameter value is null.
* @throws IllegalArgumentException if the parameter value does not
* contain at least one non-whitespace character.
*/
public static void notWhitespace(CharSequence name, CharSequence value) {
notNull(name, value);
if (value.toString().trim().length() == 0) {
throw new IllegalArgumentException("The " + name + " parameter must contain at least one non-whitespace character"); // NOI18N
}
}
/**
* Asserts the parameter value is not null and it is
* a Java identifier.
*
* @param name the parameter name.
* @param value the parameter value.
* @throws NullPointerException if the parameter value is null.
* @throws IllegalArgumentException if the parameter value is not
* a Java identifier.
*/
public static void javaIdentifier(CharSequence name, CharSequence value) {
notNull(name, value);
javaIdentifierOrNull(name, value);
}
/**
* Asserts the parameter value is either null or a Java
* identifier.
*
* @param name the parameter name.
* @param value the parameter value.
* @throws IllegalArgumentException if the parameter value is neither
* null nor a Java identifier.
*/
public static void javaIdentifierOrNull(CharSequence name, CharSequence value) {
if (value != null && !BaseUtilities.isJavaIdentifier(value.toString())) {
throw new IllegalArgumentException("The " + name + " parameter ('" + value + "') is not a valid Java identifier"); // NOI18N
}
}
}