| /* |
| * Copyright 2008 Google 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.google.gwt.http.client; |
| |
| /** |
| * Utility class for validating strings. |
| * |
| * TODO(mmendez): Is there a better place for this? |
| */ |
| final class StringValidator { |
| /** |
| * Returns true if the string is empty or null. |
| * |
| * @param string to test if null or empty |
| * |
| * @return true if the string is empty or null |
| */ |
| public static boolean isEmptyOrNullString(String string) { |
| return (string == null) || (0 == string.trim().length()); |
| } |
| |
| /** |
| * Throws if <code>value</code> is <code>null</code> or empty. This method |
| * ignores leading and trailing whitespace. |
| * |
| * @param name the name of the value, used in error messages |
| * @param value the string value that needs to be validated |
| * |
| * @throws IllegalArgumentException if the string is empty, or all whitespace |
| * @throws NullPointerException if the string is <code>null</code> |
| */ |
| public static void throwIfEmptyOrNull(String name, String value) { |
| assert (name != null); |
| assert (name.trim().length() != 0); |
| |
| throwIfNull(name, value); |
| |
| if (0 == value.trim().length()) { |
| throw new IllegalArgumentException(name + " cannot be empty"); |
| } |
| } |
| |
| /** |
| * Throws a {@link NullPointerException} if the value is <code>null</code>. |
| * |
| * @param name the name of the value, used in error messages |
| * @param value the value that needs to be validated |
| * |
| * @throws NullPointerException if the value is <code>null</code> |
| */ |
| public static void throwIfNull(String name, Object value) { |
| if (null == value) { |
| throw new NullPointerException(name + " cannot be null"); |
| } |
| } |
| |
| private StringValidator() { |
| } |
| } |